And it has been running for a couple of weeks after we got it repaired. Right into November. But suddenly the ERV started to blow cold air into the garden apartment! No more heat transfer! Running the ERV or opening windows had the same effect. Cold fresh air. Yikes!
What was going on?
I was back on the phone with the UltimateAir tech support. They suspected that the motor turning the enthalpy wheel gave out, or that the circuit board that controls that motor stopped functioning.
We went back into troubleshooting mode. I called Percy, our electrician, who arrived with his multimeter. We checked the voltage at the critical points of the circuit board. No voltage!
UltimateAir put a new board in the mail right away, and included a new motor too, just in case.
I installed the new board – et voilà, the enthalpy wheel was turning again. Because I didn’t need the new motor, I put it back in the mail to UltimateAir.