Thread: heat pump or not?

I reported this unit as an AC unit. Not a heat pump. An HVAC guy later told the client it was a heat pump that was not functioning in the heat mode. During the initial, inspection, I concluded AC only mainly because I did not see a reversing valve anywhere on the unit, not even in the service panel area. Also, the unit responded to the Tstat for AC but not for heat, and, the Tstat did not have an aux heat setting. These things combined made my initial conclusion as AC only.

I researched the label an my conclusion is that I was correct, it is an AC only, not heat pump.

Am I correct?

http://www.rheem.com/documents/rakb-...ication-sheets

Looks like AC only....

Maybe, at some time in the past, some tech (the one saying it is a heat pump) added a reversing valve, changed the thermostat, etc and said he changed it to a heat pump?

Originally Posted by John Dirks Jr

I reported this unit as an AC unit. Not a heat pump. An HVAC guy later told the client it was a heat pump that was not functioning in the heat mode. During the initial, inspection, I concluded AC only mainly because I did not see a reversing valve anywhere on the unit, not even in the service panel area. Also, the unit responded to the Tstat for AC but not for heat, and, the Tstat did not have an aux heat setting. These things combined made my initial conclusion as AC only.

I researched the label an my conclusion is that I was correct, it is an AC only, not heat pump.

Am I correct?

http://www.rheem.com/documents/rakb-...ication-sheets

I look for 4 lines, if 2 than AC only, 4 heat pump.

Steve

Do all heat pumps have reversing valves and should they always be visible to us? I did an inspection a few months ago that had a new system. It was heat pump with natural gas as aux heat. Its weird because in my area that doesn't really make sense.

But anyway, I originally thought it was an AC because I could not see a reversing valve. It was in fact a heat pump. So, if it has a reversing valve, where was it hiding?

The Rheem site information seems to indicate it is an AC unit. No mention of heat pump capabilities. Googled "Rheem rakb-024jaz"

It is the condenser for a conventional split ac (not heat pump) system with a cooling capacity ranging from 22,800 btu to 23,800 btu depending on which evaporator coil it is matched with.
These are now hecho in Mexico.

Originally Posted by Stephen Gaudet

I look for 4 lines, if 2 than AC only, 4 heat pump.

Steve

4 of what kind of lines?

Originally Posted by John Dirks Jr

...It was in fact a heat pump....

How did you become convinced that it really is a heat pump?

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So, was there no heat in this house? Or just straight electric in the air handler?

Originally Posted by Stephen Gaudet

I look for 4 lines, if 2 than AC only, 4 heat pump.
Steve

Sorry, but that's not necessarily true. I had a new Trane heat pump installed last year, and it has zero exterior lines, other than electrical and thermostat. Heats and cools like the dickens.

Originally Posted by BridgeMan

Sorry, but that's not necessarily true. I had a new Trane heat pump installed last year, and it has zero exterior lines, other than electrical and thermostat. Heats and cools like the dickens.

The unit in question is part of a split system. Are you saying you had a similar unit installed that didn't have any refrigerant lines outside? Not sure how that would work.

Also, not sure about the "four lines" post. All the heat pumps I've seen have two lines, just like a split system AC condenser.

Originally Posted by John Arnold

The unit in question is part of a split system. Are you saying you had a similar unit installed that didn't have any refrigerant lines outside? Not sure how that would work.

Also, not sure about the "four lines" post. All the heat pumps I've seen have two lines, just like a split system AC condenser.

I believe he is referring to the low voltage control lines. (Red-28v, Yellow-compressor, Orange-four way valve, blue-common).

Originally Posted by Vern Heiler

I believe he is referring to the low voltage control lines. (Red-28v, Yellow-compressor, Orange-four way valve, blue-common).

Alright then. Thanks.

Originally Posted by John Dirks Jr

Do all heat pumps have reversing valves and should they always be visible to us? I did an inspection a few months ago that had a new system. It was heat pump with natural gas as aux heat. Its weird because in my area that doesn't really make sense.

But anyway, I originally thought it was an AC because I could not see a reversing valve. It was in fact a heat pump. So, if it has a reversing valve, where was it hiding?

Dual fuel, is what I have in my home; heat-pump with gas furnace. Makes a lot of sense to have as I can use the heat-pump in the spring and fall when there is little load and the gas furnace in the cold winter. The wife forces it to the gas all the time as she likes the fast heat. Trane hides the valve behind the cowling and you have to stand on your head to see it through the slits.
This might have been a dual fuel system and the heat-pump did not come on because; the t-stat was either not configured correctly, wasn't dual fuel capable, or was broken.

Originally Posted by John Arnold

How did you become convinced that it really is a heat pump?

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So, was there no heat in this house? Or just straight electric in the air handler?

Just so the situation does not get confused. The original unit of which I started this thread over was an AC unit. (post #1) The air handler had electric resistance as the only heat source.

The other situation I mentioned (post #5) was a heat pump. I confirmed so when it came on during the heat mode of the thermostat. There was a delay as often the case and threw me off guard.

In the end, both systems were properly identified in the reports.

Originally Posted by Vern Heiler

I believe he is referring to the low voltage control lines. (Red-28v, Yellow-compressor, Orange-four way valve, blue-common).

Ok makes sense now.

Originally Posted by John Arnold

The unit in question is part of a split system. Are you saying you had a similar unit installed that didn't have any refrigerant lines outside? Not sure how that would work.

I didn't say I had a "similar system" installed, just a new Trane heat pump. It's a Model 4WCY4-1G-12, 14 SEER Single Packaged Heat Pump. Rated at 2.5 ton, but convertible up to 5 ton. No exposed refrigerant lines of any kind on the exterior; they are all buried inside the sheet metal housing.

Hey John, re: your question is the reversing valve always visible I say No, sometimes it is not visible without removing sheet metal or a vinyl jacket over the components. One more thing to be wary of.

Throw in a programable thermostat and you can really get bewildered. What I do then is hit the mode button and see what the system has to offer. (My little secret which I now share with y'all).

It's a condensing unit only.
http://www.rheem.com/documents/rakb-...ication-sheets

Originally Posted by Thom Walker

It's a condensing unit only.
http://www.rheem.com/documents/rakb-...ication-sheets

Easy way to verify if its a heat pump or not. Check the thermostat. If it has "heat, cool and emergency heat" settings, it's a heat pump. If it has heat and cool only, it isn't

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Originally Posted by Thom Walker

It's a condensing unit only.
http://www.rheem.com/documents/rakb-...ication-sheets

Easy way to verify if its a heat pump or not. Check the thermostat. If it has "heat, cool and emergency heat" settings, it's a heat pump. If it has heat and cool only, it isn't.

Originally Posted by Desmond Langton

Easy way to verify if its a heat pump or not. Check the thermostat. If it has "heat, cool and emergency heat" settings, it's a heat pump. If it has heat and cool only, it isn't

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Easy way to verify if its a heat pump or not. Check the thermostat. If it has "heat, cool and emergency heat" settings, it's a heat pump. If it has heat and cool only, it isn't.

And then pray some home owner/handyman hasn't installed the wrong thermostat, cause you may be asked to install a heat pump you said was working fine when it was an A/C unit .

Correction: Make that "homeowner/unhandyman."

There are thousands of them out there. Some of whom even charge a tidy fee for their misdeeds. I think I could write a book about all of the junk work I've come across in the last 40+ years.

Originally Posted by BridgeMan

Correction: Make that "homeowner/unhandyman."

There are thousands of them out there. Some of whom even charge a tidy fee for their misdeeds. I think I could write a book about all of the junk work I've come across in the last 40+ years.

Amen, amen, amen. Check the model number when available.

• I also do the following: set to off.
• Check that the outside unit is off.
• Set to heat and crank it up. Walk outside and the condensing unit should be running. Record air temperature at register after about 10 minutes.
• Turn it off. Walk outside and the unit should be off.
• Set it to em heat. Verify that you have heat. Walk outside and the unit should not be running.

Originally Posted by Thom Walker

Set it to em heat. Verify that you have heat. Walk outside and the unit should not be running.

... unless it is a heat pump, then it should be running, and it should be blowing cold air instead of hot air out the condenser unit fan discharge.

On heat pump systems, I always test the electric resistance heat of the air handler first. If you run the heat pump first, it's sometimes hard to tell if the aux is adequate or not since the heat pump has already warmed system components up.