Help with Purex Minimax 400 Heater

[wood-man]

I have a Purex Triton Minimax plus 400 that shuts off after the heater has been running for ~ 1 minute. What things should I look at to trouble shoot the problem?

It seems that the problem is related to heat. I pulled off the main header and check the baffles for blockage and all seems fine. Could this be a problem with a thermostat which is shutting down the unit?

Also noticed the pressure sensor is looking worn. But if this was bad I'm thinking the furnace would not fire at all. Is this correct?

Anybody have advice?

 

[Bama Rambler]

Sounds like the high temp cutout. I'd start there.

 

[Speedo]

Found out when we first had ours installed that I needed to bleed the air from then newly installed gas line. It took a minute or so and then worked just fine. Possibly there could be some air causing it to kick off because not enough gas is present. Just a guess.

 

[CraigMW]

We have the same heater, and had a similar problem when we first bought our house. The heater would run for about a minute and would then stop and I'd hear the clicking of the piezo starter. At first I thought this might be a problem with the gas solenoid valve, or due to a spider web or something. I had my pool guy come over and check it out and he spent about an hour cleaning things out, to no avail. Then he did a pressure test and found that the gas coming through the line was very weak. We ended up having to replace the 125 foot gas line because it had rusted out. I have no idea how old the gas line was, but I believe it was either black pipe or galvanized. In any event, it had to be replaced and in the process, I noticed how trashed it really was. I'm amazed that any gas at all came out. In any event, we had a trench built and ran new polyethylene pipe (yellow) that transitions to coated steel risers. Now the heater runs great. Unfortunately, this was a pretty expensive fix, but we were also able to run new electrical and communications conduits to the pool house. You definitely should do a pressure test to make sure your heater is getting enough gas.