[jlisenbe]

Installing a new water heater. This house is around 60 years old and there is no drain for the T&P valve. There is, however, a bathroom on the other side of the wall behind the water heater. Does anyone ever run a drain into the, in our case, sunken tub on the other side of the wall? See pics.

[afaroo]

Where is the water heater installed?

[Milo Dolezal]

Where is the T&P pipe now ?

You can drain T&P valve in several ways:

1. If crawl space, run pipe through crawl space and to the outside of the house
2. Install condensation collector pump, lead overflow pipe into it. Run clear tubing from condensation pump to the outside anyway you want to ( no slope necessary / use check valve )
3. If you don't mind the look of it, you can poke a hole over that tub and run 3/4" pipe from T&P valve over the tub. End it with 90 ell facing down
4. If there is a sink in that bathroom, run 3/4" pipe to the drain of the sink and connect to the drain via Branch T, above trap. ( You can also run the tubing from condensation pump to the Branch T )

Hope that helps

Milo

[jlisenbe]

Presently there is no drain for the valve. There is no crawl space. This is basically a closet it is in, but that's how it's plumbed. I'm happy to report that this house was not built by me. Might just go with idea of running something into the tub. Maybe I can dress it up some.

[massplumber2008]

Hi guys..

Hmmm... not sure about this stuff!

I don't like the idea of installing the T&P discharge tube into the bathtub (what if the T&P valve discharged or leaked when someone (kids, elderly, etc.) was in the tub?) . I also don't like the idea of connecting a 3/4" discharge safety valve directly to a branch tee fitting (reduces size of discharge tubing and that is not allowed ever!). The condensate pump might seem great for a trickle type of leak from the T&P valve, but I still see a safety issue with allowing the discharge tube to be restricted by the pump itself.

Where I'm from you either INDIRECTLY discharge the T&P valve tube to a properly trapped and vented floor drain with a trap primer (keeps trap from drying out) in the residential mechanical room, or you simply leave the discharge tube about 8" off the floor... that simple and SAFE!

You could also run the discharge tube into a crawlspace and out the side of the building (terminating in an elbow and pipe about 12" above the ground in a place away from human traffic) as Milo suggested... acceptable in most places I've worked!

If these options don't appeal to you, you could also install the new water heater in a plastic water heater pan with a battery-operated water alarm (minimum protection) in the pan, or an automatic shut off valve (maximum protection) with a sensor in the pan (google WATTS water heater gas and water safety shutoff valve) and know either way that you are doing more than most!

Just thinking aloud guys. Back to you, John!

[jlisenbe]

1. No crawl space.
2. The pan idea is worth considering. I'll take a look at that tomorrow. Thanks.
3. The concept of just letting it overflow in that closet is, at least, safe. We might have some carpet/furniture damage, but no damage to people.

[ma0641]

Is there an outside wall in the closet? If so, drain it through the all. You can run a TP drain up but you must have a way of also draining that pipe. If I need to run the TP line up, connect it to the side of a T, connect the outside drain line to the top and then a ball valve on the bottom of the T. That way, the line is drainable.

[Mike45plus]

Jilsenbe,
I don't recommend routing safety relief valve discharge piping to the outdoors, especially where seasonal outdoor temperatures hover below freezing for extended periods...

[talaniman]

For my 2 cents safety is the key question and T/P valves are for your safety. Do as your instructions recommend on the new water heater and if you don't have an acceptable drain use a bucket, and keep an eye on it. Allow enough space so the drain line is not in the bucket, but can drain to the bucket (8-12 inches should be plenty between the end of the drain line, and the bucket.).

The whole idea is free venting of your tank to relieve any dangerous pressure build up from heating water, safely, and it be OBSERVABLE. I am sure your instruction will say relieve the valve manually once or twice a year and you cannot observe and assess whether the T/P valve is functional in a closed piped situation, so I would not go that route personally, though many have, but I would hate to have a drain back up inhibit or slow that venting function in any way.

At least the free drain to a bucket will get you through until a better option can be used. Same goes for the draining into the tub where as Mark has pointed out may well catch some one by surprise and cause an injury, plus any turns and bends are just setting up potential restrictions that can bite you later in an emergency.

Straight down from the T/P valve to a bucket is my 2 cents.

[Milo Dolezal]

How far is that w/h closet to the closest exterior wall ? Just curious...

Milo

[jlisenbe]

1. The closet where the HW heater is located is pretty much in the center of the house.
2. The bucket idea might very well be workable. That could be done.

[Milo Dolezal]

Agree with the above posts: Safety is always #1. Yes, the bucket sounds like a good solution. Keep in mind that T&P valve doesn't leak all the time, but rather, it is and emergency relieve outlet for your water hater that activates only when the water pressure is over 150psi and/or temperature exceeds certain temperature. Chances are, you may never see it leaking.

Do periodical checks of your house water pressure and pay attention to sudden increase in hot water temperature at your faucets to prevent T&P valve from activating

Good luck

Milo

[jlisenbe]

Now that I think of it, there is a sort of pressure valve relief for this system already. We are on well water, and there is a 90 psi relief valve beside the pressure tank. That's outside. It would, I suppose, kick in before the one on the HW heater if that one is set for 150 psi.

[talaniman]

The water heater is a whole separate system. Your well water holding tank is not subject to thermal expansion either, just inline pressure. The water heater T/P deals in pressure from heating. I think your w/h thermostat is set at 130 or so as a low, and while it can be raised the higher the temp setting the more the T/P valve will open depending on usage of hot water.

Your kitchen and bathroom hot water faucets are also relief valves and in facts the primary, as the T/P valve on the water heater tank is the back up safety for when your usage is very low, like when you are on vacation for an example. For extended period of no usage it's recommended you turn your thermostat down. This should be covered in your manual/booklet that comes with the new water heater.