Water heater

Hi it's me again. On this particular item I had a plumber istall my new water heater because I had gas, water pipes, etc. to move. Wanted it done by someone that was certified, if you know what I mean. Didn't want to blow up the house before I even got to move in. But I digress, the water started blowing out of the valve it felt like I had a sauna in my bedroom. It is only 3 years old and has a 10 year limited warranty. Not sure what limited means in this case. Anyway do I replace the valve or the water heater. If the valve is the problem how hard is that to replace. Lots of questions. Thanks.

The very first thing any plumber that comes to install a water heating device of any kind in your home is to test water pressure. The very reason when you go to a doctor's office, the first thing they check is temperature and blood pressure. They are searching to see if there are any underlying "problems" that are relating to the "symptoms" of the situation presented.

With a brand new tank releasing water from the T&P, either it is in a closed system due to a dual check at the main or a PRV, possibly the thermostat is set up beyond the normal 120 degrees.

Replacing the valve will not correct the problem. Checking the water pressure, what is on the main line entering the building wall and checking the thermostat settings is a very good start.

Go to one of the big box stores or a local plumbing supply house and buy a water pressure gauge that you can screw into a hose connection. Works good if you can do it on a washing machine connection. Check the pressure while the heater is venting. The T&P valve on the HWH is typically set to (I think) about 125 pounds. If the gauge shows readings near there, you need one of two things - an expansion tank and maybe a pressure reduction valve (prv). To determine if you need a prv, you would need to check your static pressure. Run a faucet for 10-15 seconds (not critical) then check the gauge. If that is above say around 80 pounds, then it wouldn't hurt to use a prv. Venting from the HWH is normally one of three things: the valve is worn out (happens, but not that much), or you have a closed system (a check valve either in the water meter, separate, or in a prv), or if it already has an expansion tank, the tank is shot.

So, a little detective work, then maybe we can nail it down.

Where is the heater that you get a sauna in the bathroom from it? It could be a thermostat, or it could be water expansion. How long does it run?

Suggest you go back a few days in this section. We have had quite a series of discussions on pressure regulating valve, closed systems, and expansion tanks. I would also express my concern about the, "sauna in your bedroom". Surely the water heater isn't in the bedroom, that's totally against code and common sense.