Hi all -
Just getting the pool in shape for the swimming season and decided to fire up the heater. It is a Hayward H400 Natural Gas heater, going on 4 years old. The heater is controlled by an Aqualogic PS-8. The heater appears to fire up just fine (blower motor comes on first, followed by ignition several seconds later), but I noticed a couple things:
1 - after several seconds (maybe 30-60 seconds?), I will start to hear whining sounds - almost sounds like a baby whale looking for its mom. To me, seems like pressure that's building as the water comes up in temp, but isn't getting relieved somehow. I took out the bypass valve and made sure it was moving freely (it was), and checked the thermal control valve in a pot of boiling water and it was operating properly. After this, it seems the whining sounds have lessened, but are there other spots to check? Should these parts just be replaced?
2 - every so often (maybe every 2-3 minutes), flame will come out of the vent on the top of the unit! About 3-5 seconds later, it will "catch" itself and go back to operating normally. Only to happen again another 2-3 minutes later. Any ideas on what to check for this one?