Hi all-
I've got some time at home now with self-isolation, so I'm working on my pool equipment. My 8-year-old Mastertemp 400 won't stay lit. It's not throwing any diagnostic codes- the burner fires, but it smells bad like it is not burning right, and it even sounds wrong (deep rumble- more than normal it seems). After 5-30 seconds the burner shuts off and the cycle repeats- no codes. If I let it go, it will keep firing for a few seconds before shutting off. It worked last year, but I did notice a few times where the burner turned off and had to re-fire, so maybe the problem has just got worse. I've read the info here about the Fenwal control box, and suspect that might be one of my issues, but I don't think that accounts for the other problems when the burner is lit like the smell. I've also noticed a lot of corrosion in the heater, mostly on the top plate of the combustion chamber, including the exhaust stack (see pictures).
Like I said, this heater is 8 years old now. I'm not sure what would lead to this corrosion on top of the outside of the combustion chamber. I don't see any signs of leaks or water intrusion inside. I haven't disassembled the combustion chamber to see what the coils or heat exchanger look like.
I'm starting to wonder if it's worth diagnosing this unit any further vs replacing the entire heater. A replacement part for that corroded top plate on the combustion chamber is $500-600, plus any parts to the Fenwal control box to keep the burner lit, plus whatever is causing it to burn dirty, plus any other parts that I can find that might need to be replaced along the way.
Any tips?
I've got some time at home now with self-isolation, so I'm working on my pool equipment. My 8-year-old Mastertemp 400 won't stay lit. It's not throwing any diagnostic codes- the burner fires, but it smells bad like it is not burning right, and it even sounds wrong (deep rumble- more than normal it seems). After 5-30 seconds the burner shuts off and the cycle repeats- no codes. If I let it go, it will keep firing for a few seconds before shutting off. It worked last year, but I did notice a few times where the burner turned off and had to re-fire, so maybe the problem has just got worse. I've read the info here about the Fenwal control box, and suspect that might be one of my issues, but I don't think that accounts for the other problems when the burner is lit like the smell. I've also noticed a lot of corrosion in the heater, mostly on the top plate of the combustion chamber, including the exhaust stack (see pictures).
Like I said, this heater is 8 years old now. I'm not sure what would lead to this corrosion on top of the outside of the combustion chamber. I don't see any signs of leaks or water intrusion inside. I haven't disassembled the combustion chamber to see what the coils or heat exchanger look like.
I'm starting to wonder if it's worth diagnosing this unit any further vs replacing the entire heater. A replacement part for that corroded top plate on the combustion chamber is $500-600, plus any parts to the Fenwal control box to keep the burner lit, plus whatever is causing it to burn dirty, plus any other parts that I can find that might need to be replaced along the way.
Any tips?
