Sefe2021

[Bezin11]

Hi I have a stelpro sefe2021 and have had to change controllerboard 3 times since 2012 usually nothing works. This time turn thermostat to do a heat or cool call or hrv calls furnace blower turns on for a minute then off for minute then back on. When blower is off loose 5vdc at blower contactor coil and still have 24vac at w and c on controller board. Blower amps normal are nameplate 2.2a. Was doing some tests and noticed when thermostat isn't calling and furnace should be not doing anything one contactor for heat element gets 5vdc to coil for a minute then off for a minute element draws 20a with no blower so shut it down. Is it more than likely board again? Heartbeat led pulses 5vdc and 24vac led constant board is making a high pitch quiet sound

[Hgye]

What is your line voltage?