Water heater

[shawelectric]

I have a customer who has a water heater 8 years old(same as the house).They lost hot water ,so they replaced elements...then both thermostats...still no hot water.They called me to check it ,I found the top thermostat would shut off after 1 minute...changed it out again..new one does the same thing

 

[GoldDigger]

1. Any chance that the terminal connections to the thermostat were badly made leading to local heating that directly heated the thermostat? This is made worse if the thermostat is not in good contact with the tank.
2. If properly wired, when the top thermostat opened it should have routed current to the lower heating element until it in turned reached its set point temperature and opened. Double check the wiring to both elements and thermostats. A homeowner could easily misplace the wires during the replacement, especially if the new parts were not exact replacements and had a different terminal configuration.
3. One possibility is that the thermostat ended up actually wired line to line. If the branch resistance was high enough and/or the breaker compromised, the dead short might not have tripped the breaker but instead heated the thermostat until it opened.

 

[Dennis Alwon]

IMO there is only two thing that it can be assuming power is diverted to the lower element.

It is either wired incorrectly but even that doesn't make sense if the top element comes on for a minute or it is another bad T-stat. Did you get it at the same place?

 

[oldsparky52]

Did you change the thermal cut out?

 

[StarCat]

8 Years on what kind of water? I would remove the lower T-stat and see how much scale you detect in the bottom of the tank. Its unfortunate that there is more to the picture than just having the electrical side working correctly. I have see tanks far gone enough where you are wasting your time with what would come off as " strange behavior " of the heating system, when it should be working.
I have also seen anode rod failures which then lead to corrosion failures on cheap brands in short time.

 

[charlie b]

When you fix the issue, they will have a somewhat remodeled 8 year old water heater. I would think it better, and cheaper, to replace it.

 

[synchro]

Was it the thermostat itself that opened or was it the energy cut out (which would need to be reset if it tripped)? Also, is the heating element the proper wattage or is it oversized?

I agree with Charlie that at 8 years old it may not be worth the money and time to keep troubleshooting it.