Thought I would pose the question to the group on the off chance that one of you has seen this issue before...
Our HydroHot HHE-500-09 works just fine on the diesel burner. The electric heating element, however, has failed over time (will explain) and now trips the 120V 20A circuit breaker every time I switch it on.
Initially we noticed that the hot water would last for a shorter time than normal when showering. That lead to no hot water using the electric element only, but the breaker never tripped. Now we have progressed to the point that the breaker will trip as soon as I switch on the electric heater.
The service manual shows only 3 components in the AC heater circuit: the AC relay, the AC high limit switch, and the heating element itself. I've been troubleshooting all 3 components with the following results:
- AC relay: Working as it should. 12VDC on the primary pins, and continuity between the secondary (AC) terminals when I switch on the electric heater.
- AC High Limit: With the AC leads disconnected from the AC relay, I can read continuity from the lead that connects to the relay through the high limit switch to the heating element terminal.
- Heating element: With all leads disconnected I read 9.5 ohms across the terminals. This indicates a GOOD heating element.
I also measured resistance from the AC relay lead (the one that goes through the limit switch to the heating element) with the heating element connections in place. I get 9.5 ohms to the AC input Neutral lead (normal) and about 2K ohms from the AC relay lead to the AC input ground (copper) lead. All of this seems normal and indicates a good AC heating element.
I called AquaHot tech support and they can't think of any other test that I have not done already. Admittedly, this was their level 1 tech support guy who suggested I change the heating element, and if the problem persists, then call back and speak to their 'level 2' guy.
I'm not a big fan of the Air Force troubleshooting method (swap parts until it works
) especially since changing the heating element is such a pain in the wazoo. Wondering if anyone has seen this type of problem on their AquaHot / HydroHot system and was able to resolve it?