I have a ~2006 Hayward H400 heater (with the metal case) hooked up to Hayward Pro Logic automation controller from the same year. Quite some time ago (2 years), the keypad on the heater quit working. I thought no big deal as I always set the temp via the pool controller.
About 6 months ago, I noticed that the heater would sometimes turn on by itself and not respond to the controller - even when I set it to 'manual off'. I've finally figured out that the thing turns on after I clean the filter pump basket and close the air bleeder on top of the filter too quickly. If I close it S--L--O--W--L--Y, like taking 60 seconds, the heater will not come on. Otherwise it will, and the only way to get it to turn off is to unplug the top plug coming into the side of the heater. This cuts the gas off immediately and then the heater will eventually turn off once it's decided it's dome with it's cooldown.
Anyone experience this before? I don't want to just start throwing parts at it, but my first guess is that the dead keypad *might* be the problem. Could it be a sensor or other issue? When it's heating the spa (or, on rare occasions, the pool), it's accurate as far as temperature goes.
Any ideas would be appreciated!
About 6 months ago, I noticed that the heater would sometimes turn on by itself and not respond to the controller - even when I set it to 'manual off'. I've finally figured out that the thing turns on after I clean the filter pump basket and close the air bleeder on top of the filter too quickly. If I close it S--L--O--W--L--Y, like taking 60 seconds, the heater will not come on. Otherwise it will, and the only way to get it to turn off is to unplug the top plug coming into the side of the heater. This cuts the gas off immediately and then the heater will eventually turn off once it's decided it's dome with it's cooldown.
Anyone experience this before? I don't want to just start throwing parts at it, but my first guess is that the dead keypad *might* be the problem. Could it be a sensor or other issue? When it's heating the spa (or, on rare occasions, the pool), it's accurate as far as temperature goes.
Any ideas would be appreciated!
