Hello all my name is Chris and I've got a Pentair Mastertemp 250 heater that the mice like to use as a condo during the winter. My wires have been chewed to death and I've had to patch them up repeatedly almost every year just to get the thing to run. It seems my membrane is also toast since the pool on and spa on button no longer function and the only way to get the heater to go on and off is to set the temperature either higher or lower than the water Temperature. I've struggled with this thing for years and learned a few things about keeping the mice out of your blower by taping up the air inlet and blower out let etc. But no matter what they get inside the heater so I don't even bother to try to keep them out any more.
This year I thought I could cobb my way through another summer when I was able to get the heater to fire and run for a couple hours but now it seems that it just won't even go through the diagnostic before the membrane switch pad goes blank. I just bought a new membrane 40$ and the entire ignition control system with all wires and the box along with a new airflow switch for 145$ which looked spanking new so I thought it was a deal. I once bought a new airflow switch for like 60$ before I was told to simply blow into the old one which worked like a charm. Oh well live and learn. So now I'll have three airflow switches lol. I'm also very close to buying a new control board which would pretty much be the bulk of the electronics in the unit.
Can any one tell me if the diagnostic goes through the first couple things and then goes blank could the board still be working fine and it just has something to do with the membrane. It goes right up to the r-8 display and then goes blank but if the board was dead wouldn't it just be blank from the start? Any one who has been there done that with this unit would like to hear from you because the regular pool heater guys want like half the cost of a new unit.