Service light comes on our Raypak RP 2100 pool heater.

go to the master box and be sure no fuses are in need of reset there..then raise your water temp a few degrees..may also need to see if the burner comes on..inside..if not call your service company whomever they are..I worked for westport pools, we used to install these things.. I was in the construction part, we had a seperate service crew..but I did learn some stuff about these..

The part number for the thermistor for your heater is 005299B, officially called the temperature sensor IID it is also refered to a temp sensor or temp sensor kit.

John

high limit 135 error

Yes its faulty PC board.As no Power Coming from the board.Click this link directly to get PC board. http://www.a1poolparts.com/-strse-Heaters--dsh--Parts-cln-Raypak/searchpath/1015892/start/61/total/103/Categories.bok ------------------ To confirm the fault in PC board. Check for exact 24 volts on PC board. One yellow and One Blue wire. --------- For checking transformer check 120/240 volt to transformer(time clock circuit breaker wire connections). Thanks. Keep updated for any more query. You can rate this solution and show your appreciation.

If sound of click has changed try this; Get a small mirror that you can use to inspect in the burner tray while trying to start and inspect after dark to see if the spark is jumping anywhere it should not. Also when it is light out do the same only look closley at the pilot assembly itself and see if any soot has built up on the pilot burner this will also stop the spark from being hot enough to ignight the flame. Be sure to let any gas fumes clear each time you try light the heater as when they build up they can be very dangerious, this is also why you should use the mirror to inspect. To keep your face away from any flair ups.

press the mode button until the display reads "off". Remove the four screws holding the control cover on. Swing panel down so that the back of the board is visible. Press the mode button until "RESfl" appear. Press and hold both "up" and "down" buttons for 5-7 seconds until three dashes appear (---). This resets the fault history and clears any stored faults.