I have an Amtrol Boilermate indirect fired water heater with an oil boiler. About 9 months ago we had no hot water in our house. When I went to go troubleshoot what was wrong, I saw the Amtrol Boilermate control panel with the green light just clicking / flashing every ~2 seconds. The hot water is cycled through our house with a Taco circulator pump located at the hot water outlet from the tank.

I adjusted the hot water temp on the Boilermate, and when I got to a temp of 131, the green light went solid and the circulator pump turned on and started pumping hot water into our home.

I’ve figured out that the circulator pump will on turn on when the hot water temperate on the control panel is set to a number ending in 1. So anything besides 121, 131, or 141, the circulator pump will not turn on. I would prefer to leave the temp around ~125*, not 131 or 141. Sometimes it will still get stuck when the temp is set to one of these numbers, and I’ll have to cycle through different temp numbers to get it to turn on.

I flushed the hot water tank a couple years ago, and was planning on doing it again very soon.

I was considering replacing the thermostat in the tank, or the control panel. I just don’t want to buy a $150 control panel, replace it, and not fix the issue.

Any ideas what could be causing this?