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On my seemingly expanding list of projects is to install an overflow/drip pan under the hot water heater (this is assuming I can- have not yet verified that one would fit). Could I tap into the line for the pressure relief valve drain instead of plumbing in another pipe/line?

BTW - It's a propane heater that's about 11 years old. No signs of problems. Although the consensus seems to be to replace these with electric, my electrical service can be spotty; plus, I don't really have spare capacity for electric right now (I would have had I gotten a gas dryer to replace my electric one). Here is a picture:

Overflow & drip would be 2 different animals. Overflow ( pressure relief) is designed to prevent the tank from rupturing in the event of too much pressure. The pipe from the relieve valve should be run either through the floor or to a drain.

A drip pan is to catch water should the tank start to leak. It is a great concept, however most mobile home water heaters a buried in a closet. that said I really don't know of too many people that check the tank on a regular basis for leaks and the few gallons the pan holds will soon be on the floor as it overflows. Don't get me wrong I have one under our's, but it is more to indicate a leak than to try to contain one.

Greg

Sorry if I wasn't making myself clear... I was wanting to know whether I could tie the two -pressure relief overflow and "drip" overflow- together instead of having to plumb in a separate line/pipe for the "drip."

Yes, I know that drip pans do nothing in the event of a blow out, but would like to think that initial failures could be caught and managed (with suitable alarm).

The HWH in my "conventional" home was in a half-basement (which couldn't be finished/made habitable). I allowed a tank to just bleed out, as there was no threat to damage: nice drain in the concrete floor.

-mark

OK, ya, there should be no reason that you couldn't T the pan into the relief valve line.

Greg

Being that you have a gas water heater in a MH it is most likely a sealed combustion tank. (if its not it should be especially if its in an inside closet) Underneath the tank is a air vent that is cut into the floor to draw combustion air from under the home. Do not put a drip pan over this vent. If you want a pan you will need to pull the vent, cut a hole on the bottom of the pan, set the pan in place then install the vent through the pan. Any water that is leaked into the pan will run out the vent and go under the home. Or you could just install a water alarm.

Good Luck
Rod

Good catch Rod, I don't work with Gas units much and forgot about the intake.

Greg

I don't have a mental picture of what the bottom of one of these units might look like (anyone point me toward a picture?), but it's sounding like it's not worth bothering to install a pan. So...

If I just wait until the thing dies a horrible death do I count on insurance covering the mess? Or, with it being older would insurance tend to not cover?

I'd replace this thing now, probably with electric, if I had the time. (I've been under the mobile and it's not some place that I'm aching to return to, especially not until the weather's a bit better- it's on my todo list to repair the belly wrap [will be better prepared -can plan- now that I've ordered the repair manual!].)

Check you local code, but where I live you are not allowed to combine the TPR vent with anything else.

I feel a bit stupid, what's an "TPR vent?" Is this the pressure relief overflow? (uncertain of nomenclature)

TPR from what I understand is the vent pipe (air or exhaust). The relief valve is sometimes called a T&P valve.

Greg

Yeah, that's what I though, but just wanted to make sure. My original layman's concern was over the T&P- the exhaust vent would be a fairly obvious to me (as a layman) no-no to combine

Sorry, I did mean T&P. Here is our local code. Your's may vary, but I doubt it. I don't think anything else can connect to the T&P discharge pipe.

Pressure and temperature relief valves on water heaters shall be piped in accordance with:
a. Shall not be directly connected to a drain system.
b. Discharge through an air gap located in the same room.
c. Not smaller than the diameter of the outlet of the valve.
d. Serve a single relief device and shall not connect to piping serving any other relief device.
e. Discharge to the floor, to an indirect waste receptor or to outdoors. Where discharging to
the outdoors in areas to freezing, discharge pipe shall be first piped to an indirect waste
receptor through an air gap located in a conditioned space.
f. Discharge in a manner that dose not cause personal injury or damage to the structure.
g. Discharge to a termination point that is readily observable by the building occupants.
h. Not be trapped.
i. Not to terminate more than 6” inches above floor or waste receptor.
j. Not have a threaded connection at the end of such pipe.
k. Not have valves or tee fittings.
l. Use approved materials.

A hot water heater pan is used to catch run off from a hot water heater. It is usually made of metal and painted with a rustproof and waterproof finish. The pans also come with a drainage hole. This is important if you want to install a drain line to the pan. Some pans do not have this feature. If yours doesn't, you will have to install one yourself. Using a carbide bit drill you can simply drill a hole into the side of the pan, then attach a drain nozzle so a pipeline can be connected.
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