My Pentair mastertemp 250 has been hanging on by a thread for years now. The Mice chew on the wires and have built nests inside the unit. I can keep them out of the blower by taping up the air inlet and outlet but can't keep them out of the unit. Also the membrane switches don't work any more so I have to turn the unit on and off by using the temp control buttons. It seems to have finally given up the ghost as now the blower won't even turn on any more. I used to turn of the heater by setting the temp lower than the water and waiting for the blower to stop and then powering off the whole system. Now when I power up it goes through the regular diagnostic up to r=8 and then goes blank nothing and the blower doesn't even come on any more. Manual says get a new control board. So I ordered one and the membrane too. Has anybody had similar problems and could tell me what worked for you.