We have a Laars LX (Installed 2007) pool heater in southern Ontario. It is in use late May to mid Sept.
This heater has largely been a disappointment. We've replaced the blower twice on it.
This may be our last season as I can't abide its unreliability.
Our replacement blower (installed 2011) failed this summer (it would hum, but would not turn) so we replaced it last week with a new blower.
Upon installing the new blower, the heater went through its start-up sequence fine and we were again heating.
This was with the top off and the front access panel removed (i.e I was checking to make sure everything was ok before wrapping up.)
Upon closing up the heater (top back on, front panel back on) we again got the air flow switch error.
I re-opened the heater (top off, front panel removed). Re-started it, and everything worked fine. We were heating.
Again, upon closing it up, I got the air flow sw error.
I've checked to be sure the Fan Pressure Switch hose is well connected at the fan and the switch and that it isn't being crimped when the cover goes back on.
At this point I'm a bit stumped and would welcome any advice in case anyone has run across this one before.