Hi all,
I've got a Pentair Mastertemp 400, and similar to this thread my heater has trouble starting after the rain. The blower comes on, it ignites and heats for 2-3 seconds, and then turns off. This repeats 3 times until it gives up and the "service heater" light comes on. If I turn it off and back on it'll start the "3 attempt" cycle again. Usually after a total of 5 attempts it'll light and remain on, functioning as normal until the next rain.
At this point I've replaced the manifold bypass valve, the high limit switch, the thermal regulator, and the Automatic Gas Shutoff switch (all for other failures), but this behavior hasn't changed. It's as though something is getting wet and after heating a bit the wet area drys up and it works again, but for the life of me I can't find anything that seems to be an obvious cause. Any suggestions?
I've got a Pentair Mastertemp 400, and similar to this thread my heater has trouble starting after the rain. The blower comes on, it ignites and heats for 2-3 seconds, and then turns off. This repeats 3 times until it gives up and the "service heater" light comes on. If I turn it off and back on it'll start the "3 attempt" cycle again. Usually after a total of 5 attempts it'll light and remain on, functioning as normal until the next rain.
At this point I've replaced the manifold bypass valve, the high limit switch, the thermal regulator, and the Automatic Gas Shutoff switch (all for other failures), but this behavior hasn't changed. It's as though something is getting wet and after heating a bit the wet area drys up and it works again, but for the life of me I can't find anything that seems to be an obvious cause. Any suggestions?