TPR question

[Rick Maday]

WH on 2nd floor in room with furnace and laundry (floor drain in that room).

TPRV drain runs through floor and walls to drain in 1st floor storage room (behind a door in 1/2 bath).

Comments?

[Nick Ostrowski]

Well..............what are your thoughts Rick? Is it good, bad, or somwhere in between?

[wayne soper]

TPR drainage should be visible so you know there is a problem. Is it visible?
Termination into the pan under the water heater would be the preferred choice.

[Rick Maday]

Well..............what are your thoughts Rick? Is it good, bad, or somwhere in between?

I'm trying to find some logic to it.

It does not drain to a (easily) visible location.
It uses up a bunch of copper.
Can't tell if the copper in the wall runs uphill, downhill or loop-d-loops. (interestingly enough the direction the final end of this drain would point at the WH if they were on the same level - about 270deg worth of turns)

There is a floor drain in the room with the WH. Seems it wold be simpler (and safer) to terminate it there.

[Markus Keller]

It doesn't look like the 3/4 copper is stubbed down at all, looks either flush or slightly above the floor. I like to see them at least somewhat into the drain to keep water from splashing all over the floor.
It may not matter too much but I do have to wonder if/how much of that kitty litter has gone done that drain.
It's copper so the pipe through the wall doesn't bother me.

[Rick Maday]

Is it visible?

To this client yes - Warranty inspection. The room it ends up in is behind a door in the 1/2 bath downstairs where this client keeps the kitty box. If they didn't have cats, I don't think they'd have much reason to go in this "room". Guess the builder knew they had cats and would use this area for the litter box.

[Rick Maday]

Well..............what are your thoughts Rick? Is it good, bad, or somwhere in between?

And yours.......?

[Markus Keller]

Rick your last post just popped up while I submitted mine. If there's a floor drain in the WH room then the set-up makes me very suspicious. I agree it doesn't make sense.
Maybe the WH room floor drain got clogged with kitty litter and what we see is the fix.

[John Dirks Jr]

If the 3/4" pipe doesnt neck down, and it's discharging in a place where it wont scald a person if the TPR should discharge, and it doesn't run uphill, I cant see a problem.

Now, how about combustion air for the gas burning appliances on the second floor? Is there enough for the configuration?

[Rick Maday]

If the 3/4" pipe doesnt neck down, and it's discharging in a place where it wont scald a person if the TPR should discharge, and it doesn't run uphill, I cant see a problem.

I don't know if it runs uphill - its in the wall/floor. My biggest question is why not just terminate in same room?

I explained wht the TPRV does and why it's there and my opinion that you should be able to see if it discharges. I also refered client to AHJ - their neighbor is a code inspector for the town. (Not home at time of inspection).

Now, how about combustion air for the gas burning appliances on the second floor? Is there enough for the configuration?

I didn't do any calculations, but the duct next to the WH was for air. Also drawing air from attic through vent in the ceiling.

[Rick Maday]

If the 3/4" pipe doesnt neck down, and it's discharging in a place where it wont scald a person if the TPR should discharge, and it doesn't run uphill, I cant see a problem.

Bold is what concerns me

The following recommendations regarding TPR discharge pipes are based largely on the 2006 International Residential Code P2803.61 as well as other building and plumbing codes.

The discharge piping serving a TPR valve should:

1. Be constructed of an approved material such as CPVC, copper, polyethylene, galvanized steel, polybutylene, polypropylene, or stainless steel.
2. Not be smaller than the diameter of the outlet of the valve it serves (usually no smaller than 3/4").
3. Shall not reduce in size from the valve to the air gap (point of discharge).
4. Be as short and as straight as possible so as to avoid undue stress on the valve.
5. Be installed so as to drain by flow of gravity.
6. Not be trapped since standing water may become contaminated and backflow into the potable water.
7. Discharge to the floor, to an indirect waste receptor, or to the outdoors.
8. Not be directly connected to the drainage system to prevent backflow of potentially contaminating the potable water.
9. Discharge through a visible air gap (atmosphere) in the same room as the water heater.
10. Be first piped to an indirect waste receptor through an air gap located in a heated area when discharging to the outdoors in areas subject to freezing, since freezing water could block the pipe.
11. Not terminate more than 6 inches (152 mm) above the floor or waste receptor.
12. Discharge in a manner that could not cause scalding.
13. Discharge in a manner that could not cause structural or property damage.
14. Discharge to a termination point that is readily observable by occupants because discharge indicates that something is wrong.
15. Be piped independent of other equipment drains, water heater pans, or relief valve discharge piping to the point of discharge.
16. Not have valves anywhere.
17. Not have tee fittings.
18. Not have a threaded connection at the end of the pipe so as to avoid capping.

[/quote]

[John Dirks Jr]

Dont you hate it when you've already left the place and you wanna go back and look again? Happens to me all the time.

[Nick Ostrowski]

TPR drainage should be visible so you know there is a problem. Is it visible?
Termination into the pan under the water heater would be the preferred choice.

Everything Wayne said. And.........the same you said about all the unnecessary bends Rick. Plus, since you are in Illinois, I'm assuming you get those cold midwest winters. If the tube for that TPR exhaust to the exterior, it will be susceptible to freezing and blocking the pipe.

I know the configurations of TPR exhaust lines varies by area but in an area subject to freezing temps, sending these lines outside doesn't make sense. Straight and exhausting in plain view is what I look for. The homeowner needs to be able to see if there is a problem.

[Jerry Peck]

I'm trying to find some logic to it.

The "logic to it" (without considering the code requirements) is that the water 'will not splash all over, will not overflow the water heater drain pan, and will not leak all over when doing the preceding'.

Did you get the other items in that photo also

- combustion air size and height above the floor

- sediment traps

- access to water heater

- ??

[Rick Maday]

(without considering the code requirements)

Now that's not like you.
I was hoping for some code reference.

Did you get the other items in that photo also

- combustion air size and height above the floor

- sediment traps

- access to water heater

- ??

No - please elaborate.
No - Dirt legs were present.
Yes.

Thanks in advance.

[Ron Hasil]

Well Illinois plumbing code states as follows. Subpart d, subpart 4, states it supposed to discharge with in the same room. Also someone said they would like to see the discharge pipe go more into the drain. That would violate the indirect drainage part of the code. If sewerage backed up out of the drain bactiria and such can get into the T & P valve as well as if condtions are right the water can siphon into the water heater.

One other thing is there a vacuum relief valve installed as required in subpart f?



Section 890.1230 Safety Devices

a) All equipment used for heating water or storing hot water shall be provided, at the time of installation of such equipment, with an appropriate relief valve or valves to protect against excessive or unsafe temperature and/or pressure. This shall be achieved by installing either a pressure relief valve and a temperature relief valve or by installing a combination pressure-temperature relief valve.

b) Pressure and Temperature Relief Valves.

1) Pressure Relief Valves. Pressure relief valves shall have an ASME relief rating to meet the pressure conditions specified on the equipment served. They shall be installed in the cold water supply line to the heating equipment served, except where scale formation from hard water may be encountered, in which case they shall be installed in the hot water supply line from the heating equipment served. There shall not be a shut-off valve between the pressure relief valve and the tank. Except where an alternate design is approved by the Department in writing pursuant to Section 890.140(a)(2) or 890.1940, the pressure relief valve must be set to open at a maximum of the working pressure rating of the water heater, but shall not exceed 150 p.s.i. Each pressure relief valve shall have a test lever.

2) Temperature Relief Valves. Temperature relief valves shall bear an American Gas Association (AGA) relief rating, expressed in British Thermal Units (BTU) of heat input per hour, for the equipment served. They shall be installed so that the temperature sensing element is immersed in the hottest water within the top 6 inches of the tank. The valve shall be set to open full when the stored water temperature is 210˚F.

c) Combination Pressure-Temperature Relief Valves.

1) Combination pressure-temperature relief valves shall comply with the applicable requirements as listed in Appendix A, Table A (Approved Standards for Plumbing Appliances/Appurtenances/Devices) for individual pressure and individual temperature relief valves, and shall be installed so that the temperature sensing element is immersed in the hottest water within the top 6 inches of the tank and have a test lever.

2) A check valve or shut-off valve shall not be installed between any safety device and the hot water equipment, nor shall there be any shut-off valve in the discharge pipe from the relief valve. (See Appendix I: Illustrations N and O.)

3) Energy cut-off devices shall not be used in lieu of subsections (c)(1) and (2) of this Section and shall be of a design to properly serve the intended use of the plumbing appliance, appurtenance or device. Exception: Instantaneous cut-off devices are exempted or may be used.

d) Relief Discharge Outlet.

1) A relief discharge outlet shall be indirectly connected to waste. The discharge pipe from the relief valve shall not be located so as to create a safety hazard or to discharge in such a way as to cause damage to the building or its contents. The relief valve shall not discharge through a wall into the outside atmosphere or where there is a possibility of freezing.

2) No reduced coupling, valve or any other restriction shall be installed in the discharge line of any relief valve that would impede the flow of discharge. The discharge line shall be installed from the relief valve to within 6 inches of the floor or receptor and the end of such line shall not be threaded.

3) Any piping used for discharge from the relief valve shall be of metallic material and conform with the requirements of Appendix A, Table A (Approved Materials for Water Distribution Pipe) for potable water piping and shall drain continuously downward to the outlet.

4) The discharge piping shall discharge indirectly into a floor drain, hub drain, service sink, sump or a trapped and vented P-trap which is located in the same room as the water heater. (See Sections 890.1010 and 890.1050(a), (b) and (c).) The trap must have a deep seal to protect against evaporation or shall be fed by means of a priming device designed and installed for that purpose. (The use of a light grade oil in the trap will retard evaporation.)

e) Pressure Marking – Hot Water Storage Tank. Hot water storage tanks shall be permanently marked in an accessible place with the maximum allowable working pressure.

f) Vacuum Relief Valve. Where a hot water storage tank or water heater is located at an elevation above the fixture outlets in the hot water system, or if the storage tank or water heater is bottom fed, a vacuum relief valve as listed in Appendix A, Table A (Approved Standards for Plumbing Appliances/Appurtenances/Devices) shall be installed on the storage tank or heater.

g) Multiple Temperature Hot Water Systems. Such systems shall be provided with thermostatic mixing valves to properly control the desired temperatures.

[Rick Maday]

Ron,

Thanks a ton!

My guess (and the problem I have with this section of the code) is that often

1) A relief discharge outlet shall be indirectly connected to waste. The discharge pipe from the relief valve shall not be located so as to create a safety hazard or to discharge in such a way as to cause damage to the building or its contents. The relief valve shall not discharge through a wall into the outside atmosphere or where there is a possibility of freezing.

and

4) The discharge piping shall discharge indirectly into a floor drain, hub drain, service sink, sump or a trapped and vented P-trap which is located in the same room as the water heater. (See Sections 890.1010 and 890.1050(a), (b) and (c).) The trap must have a deep seal to protect against evaporation or shall be fed by means of a priming device designed and installed for that purpose. (The use of a light grade oil in the trap will retard evaporation.)

Are not both possible.

[Ron Hasil]

Ron,

Thanks a ton!

My guess (and the problem I have with this section of the code) is that often



Are not both possible.

When I have to install a water heater on the second floor I pipe the T&P relief to the floor drain if the drain is installed where it wont leak down to the next level. If that is not the case I ask the inspector if I can discharge it into the drip pan.

Well , best way to handle this is to call the city's plumbing inspector. He will tell you the way he interrupts the code as well what he would allow and disallow. As a plumber here in Illinois I have called and checked with the local inspectors due to each city and township modifies the Illinois plumbing code. Just always keep in mind they can make the code stricter but can not violate the Illinois plumbing code. In other words the Illinois plumbing code is the bare minimum to be allowed.

[Stuart Brooks]

Wasn't there a discussion similar to this this Spring? I seem to recall something said about the max number of bends/ells in the TPRV externsion. The number 4 rings a bell. But then, my bell seems to work sporadically anyway.

[Rick Maday]

Well , best way to handle this is to call the city's plumbing inspector. He will tell you the way he interrupts the code as well what he would allow and disallow. As a plumber here in Illinois I have called and checked with the local inspectors due to each city and township modifies the Illinois plumbing code. Just always keep in mind they can make the code stricter but can not violate the Illinois plumbing code. In other words the Illinois plumbing code is the bare minimum to be allowed.

Thanks for all your help!

I explained wht the TPRV does and why it's there and my opinion that you should be able to see if it discharges. I also refered client to AHJ - their neighbor is a code inspector for the town. (Not home at time of inspection).

I'm interested in hearing what he has to say!

[Ron Hasil]

Keep us posted, on what the town inspector has to say.