Hardie TC12b Master Valve Output Only 2V? Check AC Power & Transformer

Master valve/pump start terminal should output 24–28 VAC. If only 2V:

Check Sequence

1. Measure 120 VAC at controller power input. If missing → check GFCI/breaker.
2. If 120 VAC present but no 24 VAC at 24VAC terminals → transformer failed.
3. Replace transformer (available at electrical supply).

Battery Mode Note

On battery only, controller shows display but cannot drive outputs. Must have AC power for valves/pump relay.