I have a 3 Year old in ground Hayward H series gas pool heater. The digital readout shows "CE" and the service light is lit. I can not get the heater to fire up and the mode button is hard to change from standby to spa and pool. We did have a very rainy season this year and it is exposed to the elements. Any idea what I need to do to get it back to normal?

Pool is 4m x 8m with an average depth of 1.5m which, unless I've made a very basic math error, gives an approximate volume of 48000 L or 12680 gallons. According to some parts of the internet the water in the pool should filter 2x per day, according to others it should filter once. These are the specifications for the pump I have, unfortunately I'm not completely sure how to read it [url]http://www.espa-argentina.com/descarga/Espa-146caracteristicas-tecnicas.pdf[/url] I have the 750 model, it looks like the first graph is describing the flow based on some other variable but I'm not sure what that is. Also have no idea what the 2nd and 3rd graphs mean