How to start an AC unit when thermostat is missing

[Gene South]

I am going an inspection on a foreclosure and the control half of the thermostat is missing. The thermostat base and wiring is visibile, but the control part is missing. I am inspecting this house for a friend and the house is pretty bad shape. He just asked me if I can at least put jumper wires on the unit to find out if the unit will even operate. Anyone know if this is possible and any tips of starting this HVAC up without an thermostat?

Thanks

Gene

[Vern Heiler]

I am going an inspection on a foreclosure and the control half of the thermostat is missing. The thermostat base and wiring is visibile, but the control part is missing. I am inspecting this house for a friend and the house is pretty bad shape. He just asked me if I can at least put jumper wires on the unit to find out if the unit will even operate. Anyone know if this is possible and any tips of starting this HVAC up without an thermostat?

Thanks

Gene

the Red wire is 28v
the Green wire is Indoor fan
the Yellow wire is Compressor
the White wire is Heat
the Orange wire is the SOV (switch over valve) for heat pumps
the Black wire is Emergency or Secondary Heat " " "

Jumper what you want to happen to the Red wire. e.g.

Red to Green and Yellow for normal air-conditioner to run.

[Gunnar Alquist]

If it is for a friend, then that is one thing. But I have had experience with doing that sort of thing and can tell you that it is a can of worms if the agent sees you do this.

Several years ago, I had a wall heater that would not operate, so I put a jumper to see if it was the heater or the thermostat. The heater still did not operate, but the agent (who did not understand what I had done) mentioned it to the listing agent and it got back to the seller who demanded that I replace the heater because I "broke" it. Didn't and didn't. But, I also will not do anything other than operate the thermostat any longer.

[Scott Patterson]

I am going an inspection on a foreclosure and the control half of the thermostat is missing. The thermostat base and wiring is visibile, but the control part is missing. I am inspecting this house for a friend and the house is pretty bad shape. He just asked me if I can at least put jumper wires on the unit to find out if the unit will even operate. Anyone know if this is possible and any tips of starting this HVAC up without an thermostat?

Thanks

Gene

Vern has shown you the way to do it. But, I had the exact same scenario last week except it was not for a friend.... I told my client that I could not turn the HVAC on because the thermostat control was missing. I was not about to jumper the wires as it would not be a proper inspection of the system with a missing thermostat.

[Wayne Carlisle]

Be carefull not to ground out the system. It will blow the step down transformer.

[Elliot Franson]

The simplest way around this sort of issue is to carry an inexpensive replacement thermostat in your vehicle, preferably one that can function on either a standard split system or a heat pump setup. <$25.

[Jerry Peck]

The simplest way around this sort of issue is to carry an inexpensive replacement thermostat in your vehicle, preferably one that can function on either a standard split system or a heat pump setup. <$25.


"The simplest way" ... is to report what you found - no thermostat - and call for the system to be checked by an a/c contractor.

Not only is it the "simplest way" but it is also the safest way (electrically speaking and monetarily speaking) as that way *you* did not change or alter anything (and installing a thermostat you carry with you could still result in Gunnar's experience).

Home inspectors need to get out of the thinking that they need to "fix things" to make them work just so they can then write those same things up for repair.

Think about the illogic in that.

It is like keeping a terminally ill person who is on death row alive just so you can kill him when he comes up on the schedule.

[Elliot Franson]

The simplest way" ... is to report what you found - no thermostat - and call for the system to be checked by an a/c contractor.

Mr. Peck: Perhaps, but that is not what the OP asked.



Not only is it the "simplest way" but it is also the safest way (electrically speaking and monetarily speaking) as that way *you* did not change or alter anything (and installing a thermostat you carry with you could still result in Gunnar's experience).


Mr. Peck: Perhaps, but the OP may not be as ham-handed as Mr. Alquist appears to have been.



Home inspectors need to get out of the thinking that they need to "fix things" to make them work just so they can then write those same things up for repair.


Mr. Peck: Perhaps, but that does not amount to fixing things. It is tantamount to having a light bulb to screw into an empty socket to test that outlet. And, if you find the idea of using a light bulb too far fetched, then testing the socket with a multi-meter does nothing more than providing a viable alternative to replacing that bulb.


Think about the illogic in that.

Mr. Peck: Well yes, I have.


It is like keeping a terminally ill person who is on death row alive just so you can kill him when he comes up on the schedule.


Mr. Peck: Take yet another puff. All better now?

[Bob Harper]

Looks like A.D. "Elliot Franson" is back and just as charming as ever.

I think it is very much on point to question starting a unit that is missing its t'stat. You don't know why it is missing. You don't know what you may damage by running the system as is. If they want the AC inspected then the seller should have it placed into working order prior to your inspection. This is akin to turning on water, gas or electric service that has been shut off.

[David Bell]

Be careful on the heat pumps, reversing valves vary from manufacturer and can be cool active or heat active. Most cool active units need the O wire, G wire, and the Y wire energized for cooling. Heat active units will just need the Y and G for cooling.

[Ted Menelly]

Looks like A.D. "Elliot Franson" is back and just as charming as ever.

I think it is very much on point to question starting a unit that is missing its t'stat. You don't know why it is missing. You don't know what you may damage by running the system as is. If they want the AC inspected then the seller should have it placed into working order prior to your inspection. This is akin to turning on water, gas or electric service that has been shut off.


OK

So...If an HVAC man comes into a home, inspects the system and all appears to be in order, everything appears to be hooked up, the only thing that is missing is the thermostat that may very well have been knocked off the wall and broken when moving, the home is vacant and trashed, a client wants to know at the very least if the system is going to kick on and if the AC or heat actually blows hot or cold just so he does not have to put major money out immediately for one component of the home right away......and you are going to do what....Hook a thermostat up or jumper the wires to check further what might be going on or not??????

The point is that this home is fairly well known to be pretty much a dump that someone does not mind buying but does not want an immediate 5, 6, 7000 on a new system before they touch anything.

All other points are pretty much mute. No....I am not just sticking up for a fellow Texan because I would never do this for a client in a home inspection.

Jerry

My goodness......."keeping a man alive on death row just so you can kill him later" :eek::confused:

[Vern Heiler]

Be careful on the heat pumps, reversing valves vary from manufacturer and can be cool active or heat active. Most cool active units need the O wire, G wire, and the Y wire energized for cooling. Heat active units will just need the Y and G for cooling.

What would be the danger?

[Elliot Franson]

I think it is very much on point to question starting a unit that is missing its t'stat. You don't know why it is missing. You don't know what you may damage by running the system as is. If they want the AC inspected then the seller should have it placed into working order prior to your inspection. This is akin to turning on water, gas or electric service that has been shut off.

Mr. Harper: Though you surely look authoritative standing there, arms akimbo, your comparison is off base. Turning on utilities involves the operation of main shut-off valves or replacement of the electrical meter. A thermostat is merely a switch operated by a thermometer, just like the those found on water heaters, ovens, et al.

It is truly no wonder that so many HIs are confused about many issues when one considers the seeming total disregard for reason often encountered on this forum and others. Just my opinion.

[David Bell]

What would be the danger?
The danger is in not knowing. If you are not sure how something operates, don't operate it. Blown air handler low voltage fuses, transformers, and circuit boards are in danger.

[Vern Heiler]

The danger is in not knowing. If you are not sure how something operates, don't operate it. Blown air handler low voltage fuses, transformers, and circuit boards are in danger.

Not from not knowing wither the SOV is energized in the heating or cooling mode.

The only damage that can be caused by jumping the control wires is, as stated by someone, shorting the 28v to ground. The worst case would be to burn out the transformer which is about $18. Many of the transformers are protected by a replaceable fuse, about 75 cents. (Don't touch the red wire to the cabinet or neutral wire, if present!)

[David Bell]

Not from not knowing wither the SOV is energized in the heating or cooling mode.

The only damage that can be caused by jumping the control wires is, as stated by someone, shorting the 28v to ground. The worst case would be to burn out the transformer which is about $18. Many of the transformers are protected by a replaceable fuse, about 75 cents. (Don't touch the red wire to the cabinet or neutral wire, if present!)

Underlining is mine
The worst case scenario is a fried control board in either the air handler or heat pump. I don't deny the expense is limited, most boards are $75 to $150 but, do HIs have the parts, the time, or the certification to repair these items?

[Bob Harper]

You don't know why it was removed or disabled. you fire it up and kill the compressor because the oil has not had a chance to heat up. As DB stated, you can fry a control board, which would cost you SEVERAL hundred $$ when you include the first trip out for a tech to diagnose the problem, then order the part, go get it ,then come back and put it in, then run a system check. If anything is is going bad such as a capacitor, contactor, etc. they will surely try to dump that cost in your lap as well. Just does not seem justified to me. Now, with some of the newer equipment, you may have more than one compressor. What if they disabled it because the fan was noisy but your running it before it could be cleaned caused it to die before the tech could clean it? What if the filter was missing and you sucked a bunch of crap into the A coil and HX?

FYI, I've seen t'stats pulled because the homeowner was scared to touch the distrbution panel breakers or physically could not get there so they pulled the stat.

[Vern Heiler]

You don't know why it was removed or disabled. you fire it up and kill the compressor because the oil has not had a chance to heat up. As DB stated, you can fry a control board, which would cost you SEVERAL hundred $$ when you include the first trip out for a tech to diagnose the problem, then order the part, go get it ,then come back and put it in, then run a system check. If anything is is going bad such as a capacitor, contactor, etc. they will surely try to dump that cost in your lap as well. Just does not seem justified to me. Now, with some of the newer equipment, you may have more than one compressor. What if they disabled it because the fan was noisy but your running it before it could be cleaned caused it to die before the tech could clean it? What if the filter was missing and you sucked a bunch of crap into the A coil and HX?

FYI, I've seen t'stats pulled because the homeowner was scared to touch the distrbution panel breakers or physically could not get there so they pulled the stat.

You would be hard pressed to show a way that anything other than the transformer could be damaged by jumpering the low voltage wiring. You can't "fry" the control board even if you tied all of the wires together. If the oil is not warm by now, it never will be!

The house in question is a repo. The thermostat went the same way as the ceiling fans, mirrors, refrigerator, stove, etc. They took them! Nobody was trying to protect the equipment.

[Gunnar Alquist]

Mr. Peck: Perhaps, but the OP may not be as ham-handed as Mr. Alquist appears to have been.

Mr. Peck: Take yet another puff. All better now?

Geeze A.D., it's no wonder you were kicked-off the board already.

(Elliot Franson, AKA A.D. Miller - Ignored.)

[Jack Feldmann]

If this was for a friend, then I would call my other friend thats a HVAC guy and have him stop by.
If it was for a paying client, I'm not going to touch it and tell them to get a HVAC guy to check it out.

Jump wires? Carry a cheap thermostat? Not me! While I'm pretty comfortable with plumbing stuff, and can do a bunch of electrical things, I am lacking in HVAC repair skills.
I don't mind putting in light bulbs to check light fixtures. Mostly I only put them in the fixtures where I need light.
I carry a little cap to shut off ice maker lines that some yahoo has left open.
I have even added nuts and bolts to pull down ladders so I feel safer going up and down.

But I draw the line at doing a McGyver on a HVAC system. Maybe just me.

[David Bell]

You would be hard pressed to show a way that anything other than the transformer could be damaged by jumpering the low voltage wiring. You can't "fry" the control board even if you tied all of the wires together. If the oil is not warm by now, it never will be!

The house in question is a repo. The thermostat went the same way as the ceiling fans, mirrors, refrigerator, stove, etc. They took them! Nobody was trying to protect the equipment.

Like talking to my ex, no good is going to come out of it. Hanging up now.

[DavidR]

If the stat is missing and you start jumpering wires you have stepped outside your scope of work as a HI.

Call in a HVAC guy or call it out as stat missing.

Since this is for a friend it might be a little different as he would hopefully be a bit more understanding if the transformer got fried.

[John Arnold]

Geeze A.D., it's no wonder you were kicked-off the board already.

(Elliot Franson, AKA A.D. Miller - Ignored.)

Twice, already, actually. He's in at least his third incarnation.

Really, who knows how many of these guys and gals are actually A.D.? There could be hundreds!

[Elliot Franson]

Geeze A.D., it's no wonder you were kicked-off the board already.

(Elliot Franson, AKA A.D. Miller - Ignored.)

Mr. Alquist: "'Tis of no importance what bats and oxen think." - Emerson

[Elliot Franson]

Twice, already, actually. He's in at least his third incarnation.

Really, who knows how many of these guys and gals are actually A.D.? There could be hundreds!

Mr. Arnold: We are legion.

[Darren Miller]

Mr. Arnold: We are legion.

shouldn't it be "we are a disease?"

[David Bell]

Legionnaires
In honor of those who have no defense!

[Ed Wood]

shouldn't it be "we are a disease?"

Mr. Miller: I can't speak for you.

[David Bell]

Mr. Miller: I can't speak for you.

Believe me we all took the joke for too long.

[Elliot Franson]

Believe me we all took the joke for too long.

David: What joke would that be?

[David Bell]

David: What joke would that be?
I would reply in latin but, I tend to be more direct. The joke would be someone that feels the need to invent different personalities to remain on a board that obviously has little or no use for them. Your intelligence is constantly overshadowed by your lack of respect for others, an unwillingness to admit any mistakes and, to be honest, I think your time would be better spent surfing porn sites. I wish you well in your future personalities and I pray for your family.

[Elliot Franson]

I would reply in latin but, I tend to be more direct. The joke would be someone that feels the need to invent different personalities to remain on a board that obviously has little or no use for them. Your intelligence is constantly overshadowed by your lack of respect for others, an unwillingness to admit any mistakes and, to be honest, I think your time would be better spent surfing porn sites. I wish you well in your future personalities and I pray for your family.

Mr. Bell: Your abusive post has been report to Mr. Hannigan.

[Jerry Peck]

Mr. Bell: Your abusive post has been report to Mr. Hannigan.

Did you report it as the report being from the banned user A. D.?

Be careful what you wish for, you may just get involved and end up on the short stick. :D

[David Bell]

Mr. Bell: Your abusive post has been report to Mr. Hannigan.

I would like to take this opportunity to apologize for this thread going awry. It seems I could not resist the bait. While Elliot,Ed,Aaron or whatever his latest incarnation is, found my words abusive, rest assured they were sincere. Brian will have the last word on this, as he should.

[Elliot Franson]

Did you report it as the report being from the banned user A. D.?

Be careful what you wish for, you may just get involved and end up on the short stick. :D

Mr. Peck: Let Jerry worry about Jerry. Elliot can fend for himself, I assure you.

[Elliot Franson]

I would like to take this opportunity to apologize for this thread going awry. It seems I could not resist the bait. While Elliot,Ed,Aaron or whatever his latest incarnation is, found my words abusive, rest assured they were sincere. Brian will have the last word on this, as he should.

Mr. Bell: Your incessant groundless accusations notwithstanding, your apology is accepted, even if it was not directed toward me.

[William Brady]

this is destroying the whole purpose of Inspection News. I come hear for tips and knowledge not this. Can someone tell me how to ingore this guys Elliot

[Jim Luttrall]

this is destroying the whole purpose of Inspection News. I come hear for tips and knowledge not this. Can someone tell me how to ignore this guys Elliot
Go to the "User CP" at the top left hand of the page under the inspection news banner then to the buddy/ignore list and you can add anyone you wish to the lists. Of course if that person is quoted, you will still see their quote but it is better than nothing.

[Don Horn]

Unless you are a licensed HVAC contractor do not attempt to rewire. This goes beyond the scope of an inspection and you assume liability.

[Mitchell Toelle]

Unless you are a licensed HVAC contractor do not attempt to rewire. This goes beyond the scope of an inspection and you assume liability.

Thank you!!!! End of discussion. Oh yea....he's a friend....go for it...but be ready to pay to keep your friendship should anything go wrong.

[James Duffin]

I inspected a foreclosure today and the A/C did not work when operated with the thermostat. The heat worked fine. Upon inspecting the condensate pump I saw the wire to the float switch had been disconnected. At her request after a brief lesson in HVAC controls I hooked it back up and the condensing unit started humming but did not come on. Since this was an as-is sell the lady buying the house was glad to know that the A/C does not work. I see that as no difference as jumping out a thermostat and it will help her make up her mind as to what she is going to do.

[David Bell]

I inspected a foreclosure today and the A/C did not work when operated with the thermostat. The heat worked fine. Upon inspecting the condensate pump I saw the wire to the float switch had been disconnected. At her request after a brief lesson in HVAC controls I hooked it back up and the condensing unit started humming but did not come on. Since this was an as-is sell the lady buying the house was glad to know that the A/C does not work. I see that as no difference as jumping out a thermostat and it will help her make up her mind as to what she is going to do.

You don't know whether the A/C works or not, what you know is that after hooking up a safety switch wire the contactor pulled in and was humming. The disconnect could be off, the circiut breaker could be off.

[James Duffin]

Had power and the compressor relay pulled in....so in my opinion it did not work. The wire was probably disconnected because it was not working but you never can tell without checking.

[Scott Patterson]

This thread has simply amazed me at the number of folks who would attempt to try and start up an HVAC system with the thermostat missing! Yet, I bet nobody who would wire up a spare thermostat or jumper the wires together would ever think about turning on a water valve to a sink, toilet, or whatever if it was turned off. Ya know, the more I thought about it I bet they would turn every off valve they found in a home.

Simply stated; If the thermostat is missing the system does not work! That is what you need to report....

[James Duffin]

It would have done this lady no good for me to tell her the A/C did not work. She already knew that since it was sitting there not doing anything. Now she knows that even with power applied it still does not work without spending $120 for a service call to tell her the A/C does not work. This is an as-is sell so no repairs are being done by the seller. Plus the NC SOP allows me to do that if qualified.

[Rick Hurst]

This thread has simply amazed me at the number of folks who would attempt to try and start up an HVAC system with the thermostat missing! Yet, I bet nobody who would wire up a spare thermostat or jumper the wires together would ever think about turning on a water valve to a sink, toilet, or whatever if it was turned off. Ya know, the more I thought about it I bet they would turn every off valve they found in a home.

Simply stated; If the thermostat is missing the system does not work! That is what you need to report....


Scott, I was thinking the same thing.

I was wondering if it had been the condensing unit missing, how many would have hauled in one to hook up just to see if the indoor evaporator coil was working on not?

rick

[David Bell]

Scott, I was thinking the same thing.

I was wondering if it had been the condensing unit missing, how many would have hauled in one to hook up just to see if the indoor evaporator coil was working on not?

rick
Not being an HI, I think in contractor terms.

[James Duffin]

I, for one, don't carry that many spare parts...Only use what the good lord gave me. ;)

[Bob Harper]

Or, following Rick's lead, what if the outdoor disconnect was missing and you have a spare on your truck that matched that box. Would you insert the disconnect and power up the condenser? What if it is a fused disconnect with the fuses missing? Would you provide fuses and attempt to run it?

The seller knew the stat was partially disasembled and missing. They knew why this was so when they listed the house. There should be something in the disclosure form even if it is being sold 'as is'. They knew no one would be able to fire up that AC without it, which is apparently what they wanted, even if it meant a lower price for the house. Their choice. As Scott said, document the missing stat, which precluded you from running the AC. You can document the presence of an A coil and outdoor condenser but note you were unable to run them-done.

FYI, it is illegal for a H.I. to do this in Delaware. You cannot 'repair' any part of an HVAC system unless you hold an HVAC license and New Castle Co, De WILL fine you. Know your local laws.

[James Duffin]

I know my laws....I do hold a NC Mechanical license. I have stated that before and did not see a need to repeat myself until now.

[Elliot Franson]

Scott, I was thinking the same thing.

I was wondering if it had been the condensing unit missing, how many would have hauled in one to hook up just to see if the indoor evaporator coil was working on not?

rick

Mr.Hurst: Can we borrow yours?

[Scott Patterson]

I know my laws....I do hold a NC Mechanical license. I have stated that before and did not see a need to repeat myself until now.

James, that is great that you have that license but I would estimate that around 99% of the home inspectors in the country do not have a license to work on HVAC systems. You are an anomaly in our profession.

[Rick Hurst]

Mr.Hurst: Can we borrow yours?


I have a slightly used failed evaporator coil if you wish to borrow it. I mean "rent" it out. Need to recover some of my expense.

rick

[Elliot Franson]

I have a slightly used failed evaporator coil if you wish to borrow it. I mean "rent" it out. Need to recover some of my expense.

rick

Mr. Hurst: Do you suppose that Mr. Patterson would spring for the rent?

[James Duffin]

James, that is great that you have that license but I would estimate that around 99% of the home inspectors in the country do not have a license to work on HVAC systems. You are an anomaly in our profession.

I hope me having trade licenses does not mean I can not contribute to the discussion. I was just stating what I do as another point of view. No one else has to do it or agree. That is not the point of a forum...to have a consensus on everything would be boring.

[Vern Heiler]

FYI, it is illegal for a H.I. to do this in Delaware. You cannot 'repair' any part of an HVAC system unless you hold an HVAC license and New Castle Co, De WILL fine you. Know your local laws.
From NC General Statutes Chapter 87, Article 2.

(c) To Whom Article Applies. – The provisions of this Article shall apply to all persons, firms, or corporations who engage in, or attempt to engage in, the business of plumbing, heating, or fire sprinkler contracting, or any combination thereof as defined in this Article. The provisions of this Article shall not apply to those who make minor repairs or minor replacements to an already installed system of plumbing or heating, but shall apply to those who make repairs, replacements, or modifications to an already installed fire sprinkler system.

[Scott Patterson]

I hope me having trade licenses does not mean I can not contribute to the discussion. I was just stating what I do as another point of view. No one else has to do it or agree. That is not the point of a forum...to have a consensus on everything would be boring.

Not at all.... I was just pointing out that the vast majority of home inspectors do not have a license as you do. You might want to add to your profile that you do have a mechanical license, then folks could easily see that is your speciality.

[Ron Bibler]

They stab it with their steely knives, But they just can't kill the beast. :D

Dude...AD...

Best

Ron

[Rick Hurst]

Last thing I remember, I was
Running for the door
I had to find the passage back
To the place I was before
’relax,’ said the night man,
We are programmed to receive.
You can checkout any time you like,
But A.D. can never leave!


So see, he's still welcome.:D

[David Bell]

On a dark inspection website, He got thrown off for a post, He said that he did nothing wrong, but he did piss off the host, He went back to his man cave, and invented a new name, The people all new who he was, cause he acted just the same. Chorus here

[David Bell]

Scott, the new pic is much better.

[Scott Patterson]

Scott, the new pic is much better.

Yep, that is what my lovely wife said when she took it..

[Rick Hurst]

I can't see him due to the reflection of the lights. ;)

rick

[Ron Bibler]

I can't see him due to the reflection of the lights. ;)

rick

All of us need to reflect now and then:D

Best

Ron

Bunch of sick twisted freeks...:eek:

[Jerry Peck]

Scott, the new pic is much better.

Looks to me like those players in the background have gone deep and are about to cream Scott from the backside if he does not turn around and catch that dang football then run it in!

:D

[Paul Kondzich]

This thread should have been dead weeks ago. Lets say you see something you have never seen before, maybe Chinese or a better term is "defective drywall." Are you going to rip out all the drywall, the wiring and everything else affected, replace everything and come back in 6 months to check it out now?? Report what you see (or smell) and move on with life...

[Nick Ostrowski]

Install a temporary thermostat? Jump the wires? You guys are nuts.

Thermostat damaged and inoperable - HVAC system could not be tested for operability - have entire HVAC system serviced by a HVAC professional and all repairs/replacements made as needed

Done.

[Jerry Peck]

Thermostat damaged and inoperable - HVAC system could not be tested for operability - have entire HVAC system serviced by a HVAC professional and all repairs/replacements made as needed.

This is better wording: ( changed the wording in bold red)

Thermostat damaged and inoperable - HVAC system DID NOT WORK - have entire HVAC system serviced by a HVAC professional and all repairs/replacements made as needed.

There you are -you have now said exactly what is needed "DID NOT WORK" (it did not), and thus it needs to be repaired (it does need to be repaired).

Saying it "could not be tested for operability" is like saying 'it might work, but I just could not test it' - but you DID test it, and it DID NOT WORK (of course it did not work, the thermostat was missing, but that is no different than if the breakers had been removed and "it did not work".

Your client needs your report to say what you found ... that it "did not work".

I'm not sure what is so hard about that. There could be many reasons "IT DID NOT WORK", are you going to carry spare parts to cover all scenarios? Of course not! Not even James carries spare parts to cover ALL scenarios, so just write it up for what you did find.

[Nick Ostrowski]

If the thermostat was intact and the system did not activate, then you could say "HVAC system did not work". If the thermostat is broken (and the thermostat is integral to getting the HVAC system to operate under normal conditions), then it is not accurate to say "HVAC system did not work" as that would infer you attempted to activate the system and it did not respond to normal operating controls.

The system might operate properly if it had a functional thermostat. But at this point, it is up to the HVAC pro to determine what does or doesn't need to be done.

[Jerry Peck]

If the thermostat was intact and the system did not activate, then you could say "HVAC system did not work". If the thermostat is broken (and the thermostat is integral to getting the HVAC system to operate under normal conditions), then it is not accurate to say "HVAC system did not work" as that would infer you attempted to activate the system and it did not respond to normal operating controls.

The system might operate properly if it had a functional thermostat. But at this point, it is up to the HVAC pro to determine what does or doesn't need to be done.

The thermostat is part of the system, and the system did not work. Plain and simple, cut and dried.

What you area saying is like the condenser unit coil was missing, but you cannot say the system did not work as you do not know that unless and until you install a condenser unit coil and try to operate the system.

Chose any part of the system and you can say the same thing.

Does that then mean you can never say the system does not work?

[Nick Ostrowski]

Does that then mean you can never say the system does not work?

I saw a dishwasher in a house the other day where the drain line was not connected to the sink drain and would have exhausted water into the cabinet if I had tried to operate it. The unit might work properly if the drain line were hooked up. But I don't know what it would or wouldn't do as the installation was not complete. To say in this case "the dishwasher did not work" would infer I attempted to turn it on and it did not respond. That isn't the case. Likewise, saying a heating system, that has a damaged or missing thermostat, does not work would infer I attempted to turn it on and it did not respond.

[Jerry Peck]

I saw a dishwasher in a house the other day where the drain line was not connected to the sink drain and would have exhausted water into the cabinet if I had tried to operate it. The unit might work properly if the drain line were hooked up. But I don't know what it would or wouldn't do as the installation was not complete. To say in this case "the dishwasher did not work" would infer I attempted to turn it on and it did not respond. That isn't the case. Likewise, saying a heating system, that has a damaged or missing thermostat, does not work would infer I attempted to turn it on and it did not respond.

The above would be applicable if we were discussing not running the a/c system because the condensate drain went to a condensate pump and the drain line from the pump was not connected.

However, it is not anything like what we are discussing, but THIS IS: you go to check a dishwasher and the control panel is missing (that is what a thermostat is, the control panel for the a/c system. You then can report the dishwasher was not working ... then continue with (just like with the a/c system) ... the dishwasher was not working, the control panel was missing, have the dishwasher repaired as needed ... which is the same as saying that the a/c system did not work, the thermostat (i.e., control panel) was missing, have the a/c system repaired as needed.

I really do not understand what is so hard about this concept, but I really am trying to find what must be a complicated reason as all the simple reasons say that the thermostat is the control panel for the a/c system and that without the control panel the a/c system did not work, and that the a/c system needs to be repaired as needed.

That means that an a/c contractor comes out, looks at the a/c system and determines as best possible that replacing the thermostat is not going to cause any further damage, replaces the thermostat, operates the system, then determines what else is not working right. That is, after all, what they are paid to do. It is not, after all, what the home inspector is expected nor paid to do.

[Nick Ostrowski]

My verbiage works fine for me.

[William Brady]

Hello, the AC unit did not respond to normal controls, end of story. The dishwasher drain was not connected, end of story. The furnace did not come on using normal controls, thats it. Now if you want to interfer with a long selling process and remember we get paid the others or commission people, then, keep trying to make this inspection process more complicated then it should be. Some things of course need to be addressed and thats what we are paid for but we are not paid to be a pain in the you know what. We can argue this point forever some will always let the ego get in the way of a good business practice.

Sorry I just got carried away don't mean to offend anyone.

[Nick Ostrowski]

Don't hold back Bill. Tell us what you really think.

[William Brady]

At times I just get worn out reading these long posts. I need to get a NOOK so I can keep up all day long.

[ray jackson]

If I can continue to string this thing along. As an A/C technician, when I come across something unusual like a missing stat, or unplugged/switched off piece of equipment. I always look the system over checking for debris in the blower housing and who knows what else. As far as a missing stat, I always check that the wiring is correct at the unit. Just because a wire is red doesn't mean it's 24v hot. Actually that wire will be whatever you want it to be. Heck, that wire doesn't even know it's red.:D

[Vern Heiler]

If I can continue to string this thing along. As an A/C technician, when I come across something unusual like a missing stat, or unplugged/switched off piece of equipment. I always look the system over checking for debris in the blower housing and who knows what else. As far as a missing stat, I always check that the wiring is correct at the unit. Just because a wire is red doesn't mean it's 24v hot. Actually that wire will be whatever you want it to be. Heck, that wire doesn't even know it's red.:D

Good point!

[Eric Russell]

This thread has simply amazed me at the number of folks who would attempt to try and start up an HVAC system with the thermostat missing! Yet, I bet nobody who would wire up a spare thermostat or jumper the wires together would ever think about turning on a water valve to a sink, toilet, or whatever if it was turned off. Ya know, the more I thought about it I bet they would turn every off valve they found in a home.

Simply stated; If the thermostat is missing the system does not work! That is what you need to report....

Well said, Scott. I'm chiming on this one a little bit late, but I too am amazed that anyone would consider operating the HVAC, or any other equipment that had no thermostat, a breaker flipped off, a shut-off valve turned off, etc. Call me crazy, but if it doesn't work, I report it as not working! There is usually a good reason things are turned off. Maybe a leaking pipe past the shut-off valve in the plumbing system...perhaps a short in a wire somewhere inside a wall...defective or dangerous pre-existing conditions that i'm unaware of! Am I going to be responsible for burning down a house because I flipped a breaker back on to check an outlet...NO. A home inspection in TN is still a visual, non-invasive, inspection of readily available and accessible systems and components. The state SOPs also state that a readily openable access panel provided for homeowner inspection. Getting into electrical wiring to check whether or not a unit is operable falls outside that scope. That is stuff better left to the guys with the expertise necessary to be in there! While we're on the subject, naaaaahhh...never mind...I'll start a new thread for that...we kinda got off topic on this one already, and I just added more fodder...

[Markus Keller]

For a friend, I would jump it out. However, I would jump it out at the board so that I can assess the unit, see what's going on and keep anything funky from happening.
For a regular HI, it is highly doubtful I would jump it out. Either way I wouldn't jump it out at the stat. If you do it at the stat you can't see what the unit is doing to know whether there is a problem or you should stop. Wire colors are standard but you never know what's hooked to what for sure. I've seen colors completely screwed up. Always want to check at the board.
Jumping the wrong posts briefly is unlikely to blow the trans, maybe the board fuse. Jumping the wires at the stat location and then walking down to the unit could be long enough to blow the trans but again the board fuse will probably go first.
Having had a few units short out while removing covers, because someone messed with the blower cut-off switch, I keep a pack of fuses in my kit just in case.
Everyone does what they are comfortable, I wouldn't recommend it though.