TPR Discharge

Home built in 2001. TPR discharge piping discharging into a trash can. The home owner indicated that she is having to empty the trash can every week using a wet/dry vacum with a pump and drain line. Has anyone else ever run into a set-up like this?

Is it overheating What is the water pressure? Is there an expansion tank?

Also, the 2 TPR valve relief extensions cannot be connected to one pipe together.

504.6 Requirements for discharge piping.
The discharge
piping serving a pressure relief valve, temperature relief valve
or combination thereof shall:

  1. Not be directly connected to the drainage system.
  2. Discharge through an air gap located in the same room
    as the water heater.
  3. Not be smaller than the diameter of the outlet of the
    valve served and shall discharge full size to the air gap.
  4. Serve a single relief device and shall not connect to piping
    serving any other relief device or equipment.
  5. Discharge to the floor, to an indirect waste receptor or
    to the outdoors. Where discharging to the outdoors in
    areas subject to freezing, discharge piping shall be first
    piped to an indirect waste receptor through an air gap
    located in a conditioned area.
  6. Discharge in a manner that does not cause personal
    injury or structural damage.
  7. Discharge to a termination point that is readily observable
    by the building occupants.
  8. Not be trapped.
  9. Be installed so as to flow by gravity.
  10. Not terminate more than 6 inches (152 mm) above the
    floor or waste receptor.
  11. Not have a threaded connection at the end of such piping

ha ha… thought Larry was answering Larry for a minute.:slight_smile:

If those are original (2001) The TPRV’s are beyond their normal life expectancy.

Good chance you have faulty valves.

Borrowed from a very knowledgeable inspector.

Thanks. Also, would this be considered a cross connection with the discharge tube in the water of trash can?

Would the water heater TPR discharge into the furnace condensate pump satisfy these requirements (is this from the Mechanical Code)?
I would think that if the valve actually discharged that it would overflow the pump receptor anyway but do these valves sometimes leak and drip, indicating a possible future failure that would not be detected with the attached installation?
Any suggestions on how to right this up?

Absolutely not.

Any time you’re looking for a way “to write something up,” it’s easy when you just keep it simple. You could give a long explanation of how it should terminate out doors, or through an air-gap, but to keep it simple, just state;

The termination of the discharge piping for the water heater TPR valve is improper, and should be corrected by a qualified plumber.

If someone asks you “what’s wrong” or “how should it terminate,” explain it to them, and then let them know that if the plumber is actually qualified, he/she will know how to correct it.

Check the expansion tank to make sure it has not failed, I’ve seen a water heater that continued to leak even after changing the TPRV. Further investigation found that the bladder in the expansion tank failed and that coupled with excessive water pressure 90+ psi it leaked. Just a thought as to what might be the cause.

Even though we are not required to identify the cause I think its very benefical to know not just for the personal satisfaction but it also gives you a different perspective on inspecting

Jeff’s response is well thought out.

And here is the "504.6 Requirements for discharge piping." link:

Thanks Larry for the code verbiage.
After I sent the post, I went back to the InterNACHI “25 Standards Every Inspector Should Know” for a good summary and note on the possible dripping that could occur, along with item 7 that the discharge must be readily observable by the building occupants.
This will be my simple response that it is not readily observable.