Heater Problem - Black Smoke

[DaveV]

Hi - I have a Pentair MiniMax, about 5 years old. Always worked great. This year when I first turned it on, fumey black smoke came out of it while it was operating. It did heat the water, but the smoke continued. It left a sooty dust on top of the heater. Something aint right. Anyone know what?

[Poconos]

Don't know anything about that heater but I assume it's either nat gas or propane. In either case sounds like a very rich mixture which on a gas heater can be caused by blocked combustion air flow or the pressure regulator went ape and the gas pressure is way high. Can you look at the flame and see what it looks like? Should be mostly blue with orange flame tips I believe, for the right fuel/air mixture. If the gas pressure went high you should see an abnormally large flame too. the soot is a sign of incomplete combustion.
Al

[gottliebo]

Hi - I have a Pentair MiniMax, about 5 years old. Always worked great. This year when I first turned it on, fumey black smoke came out of it while it was operating. It did heat the water, but the smoke continued. It left a sooty dust on top of the heater. Something aint right. Anyone know what?

This is a guess but if you had the pool shutdown for the winter and live in a colder climate like I do (Wisconsin), it could have been mouse nest. Happened to me 3 years ago. There was a nest built on the burners and another above the heat exchanger. The little buggers chewed through the insulation and used some of that to make the nest. Now I check it every spring before firing it up.

[waste]

I'm pretty sure these are like the Max-E-Therm heaters by Sta - Rite, both of the above suggestions are reasons for this but think that gottliebo's answer is more likely. I've seen many heaters where mice have found their way into the ignition chamber and nested . However, if the unit has fired and sustained ignition a few times for a while, eventually the nesting materials would be fully consumed, as would the nesters So perhaps there is an issue with the air/ gas mix

[CarlD]

And here I was thinking: Maybe get some marshmallows?

(sorry, couldn't resist! )