My pool heater front board temperature is flashing but i can control the modes of the heater. replaced the board yesterday and it worked fine???

SOURCE: service light on

I just had the same problem resolved, my mastertemp 400 would run up the temp to 82F and then cutoff, the service light flashes and then 50 seconds later the heater would restart and run for 2 minnutesbefore shutting down again and relighting in 50 seconds. Repeating until the temp setting is reached.

I had the pool guy out 3 times until he found a bad thermal regulator valve (kit #77707-0010). Once replaced the heater runs great.

He told me that it's my pool chemestry that is to blame, I had it checked (like I do weekely by me and monthly by the pool supply store) and it perfect??? I'm now questioning what caused the corroson and stop it from coming back?

I hope tis helps.

SOURCE: My Laars Lite 2 will not ignite.

I figured it out on my own.

SOURCE: PUREX TRITON MINIMAX 400 Pool Heater Control Board

DId yo find the problem? My heater is doing the same thing.

SOURCE: Service light comes on our Raypak RP 2100 pool heater.

this usually indicates a high limit condition.you must first ascertain if you have a component failure or a true high tempature condition.your model has 2 limit controls and they are both located in side panel on water in/out header

SOURCE: I have Jandy RS4 system with 4-button poolside

Pull the cover off the control panel. You will probably find a button which would be accessible from outside the panel with a paper clip or pencil but is unlabeled. On the board itself by the button, in small letters it should say "reset". Push the button and see what happens.