Jonathon Pullen
Technical Services Manager
Gulf Coast District
The Infamous E1: Part 2
E1 fault code on Ductless equipment is communication fault between the indoor and outdoor units.
When the E1 code shows up on the indoor display board, the coms have failed and the systems have stopped working. Until this problem is fixed, the system will remain off.
Start trouble shooting this problem at the outdoor by taking a DCV reading on L2 and S or 2 and 3 depending on how the unit is labeled. Take a DCV reading on the terminals for the indoor unit wires.
Good coms volts look like + to – 50 volts fluctuation.
If you see a fixed negative or a small amount of fluctuating volts staying in the negative, the indoor board has failed.
If you see a fixed positive volt reading or a fluctuating positive reading the outdoor board is bad.
The reactor also needs to be checked. Check the reactor with the wires off and ohm it out. The ohm reading should be .1-1 ohm and should not be grounded.
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