Waterheater lukewarm only

[Kenneth Efinger]

Have (had) 7 yrs old GE40M06AAG unit. Started putting out lukewarm water. Temp settings not changed (125). Even though the heating elements tested fine as well as the thermostats, changed all out for new.
Still lukewarm. Replaced unit with Rheem XE40T06ST45U1. Problem still the same with new unit.
Irrelevant, but unit has an expansion tank installed on the cold line.
Any ideas?
Also replaced electric line from breaker to unit in case of short....

 

[Sarg]

Only thing I can think of is the breaker.
Have you checked the input voltage ?

 

[Sponsor]

 

[Reach4]

Turn off the WH. Turn off the valve to the WH water.

See if your hot water spigots deliver water under pressure. If so, you have a cross-connection.

 

[Phog]

If you have access to one of those instant read IR thermometer guns you could measure the temperature of the hot water pipe directly at the top of the hot water tank. Approximately $50 tool available at home depot, and ask your neighbors too, they're pretty common.

Measure it with a hot faucet on, leave it running for 60-90 seconds to let the pipe get up to temperature, and then see what temperature is. You've fixed all the possible problems with the hot water tank and it seems more likely that you're getting cold water mixed into the hot water pipe somehow, downstream after the hot water leaves the hot tank but before it reaches your faucet. Which is leading to warm water. Taking the temperature right where the water comes out of the tank will help verify that.

Last, to use an IR thermometer on a metal surface like copper or steel, you usually have to put a piece of tape on it or something like that (a spray of krylon will also work). And aim the thermometer gun at the tape instead of the bare metal.

 

[Kenneth Efinger]

Replaced the 30amp breaker already....

 

[Fitter30]

Need a volt meter and clamp on amp meter. Water heater first the top element heats upper 1/2 when thermostat satisfies sends power to lower element till lower thermostat satisfies unless after using water cools top thermostat and power goes to top element. 4500 watt element 18.75 amps @240 volts