GE Gas 40 gallon hot water heater...not hot enough?

**Aaron65** · 03-03-2013, 03:24 PM

My old State 40 gallon gas hot water heater started banging around recently, so I flushed it out...long story short, it was 15 years old and I replaced it, even though it worked great. I didn't want to come home to a mess. It was banging loud enough that I could hear it on the first floor from the basement. I bought a 40 gallon GE (Rheem) from Home Depot. I have a mix of galvanized/plastic/copper plumbing in my basement, and my basement is about 6 feet tall on a good day. I ended up hooking up the new heater with stainless steel flex pipes, and I had to loop the hot tube and install the cold in a 180 degree bend. Neither is kinked. It doesn't look super professional, but it fits. After my wife complained of a shower that got cold after 15 minutes, I turned the thermostat from 120 to 130, then to 140, and finally to 150. It's better, but she's still getting cold at the end. I called GE, and they sent out a new sensor/thermostat, which I installed. I put the thermostat on 140 after I was done. My shower on the first floor seemed to have plenty of hot water, but I did have to turn the cold mix down as I took a shower. If I turn the cold off, it's scalding hot even after 10 minutes. In her shower upstairs, which has never been as hot as mine, I now can barely turn the cold mix on to maintain a decent temperature. This was not a problem before the new hot water heater. So--I'm wondering what I may have done wrong, or if there's something wrong with the heater itself. Any input is appreciated...Thanks!

**jadnashua** · 03-03-2013, 03:56 PM

First, when you run the WH above 120-degrees, you must install a tempering valve for safety reasons.

IF the valves are anti-scald, they also have an adjustable limit stop in them to set the maximum shower water outlet. You may need to adjust those. In the process of turning the water off, then filling up the new WH, you could have dislodged some crud in the pipes that is now caught in the valve or cartridges or showerhead. It also would momentarily create a mismatch in the pressure on the hot/cold side of the valve, and if it is an anti-scald valve, it could have jammed the spool valve to one end. Some valves also have check valves inside them, and those can get lodged to one end or obstructed with crud.

Some valves can develop an internal cross-over, and thus mix some hot with the cold all the time. This can limit how hot a local branch can become, since it is already being mixed. A vanity faucet, or a tub/shower one can do this and usually is fixed by replacing the cartridge.

This should give you some things to check, but may not answer your question.

**Terry** · 03-03-2013, 04:51 PM

In addition to the above post, the shower head determines how long a shower you can take. Some heads just dump water out.

**Aaron65** · 03-03-2013, 06:40 PM

Thanks for all the fast answers! The water pressure seems about the same as it's always been, but it's certainly a possibility that some crud got dislodged. I'm going to guess there's no anti-scald valves in the system...the shower valves are pretty old. It's certainly worth the effort to pull those out and flush everything, and replace the cartridges. How do you tell if it's an anti-scald valve?

**jadnashua** · 03-03-2013, 06:52 PM

If it has a separate valve for each of the hot and cold, it almost certainly isn't (there are a few exceptions, but not generally done with a separate pressure balance valve). If it's a single handle, it probably is. They've been required for quite awhile now...how old are they?