Midas B


Problem Solution

1. Flow switch fails closed

2. Pump failure

3. Overheat stat out of calibration, check temperatures

No hot water or heating

Relay PCB is prone to failing, visually observe the relays as a hot water tap is opened and closed, both relays should operate. check fuses on board before ordering a replacement.

radiators warming with hot water demand

non return valve in bottom connection of heating pump may need replacing


Midas SI


Problem Solution
boiler not operating if lights 1, 2 &5 are on the PCB then check the normal/purge switch for continuity. If no continuity then switch is faulty
pilot on but no main burner

check pilot for correct size, check low gas pressure is correct, check inline resistor for breaking down, spark jumps across the break but prevents rectification

fan cycling

check main overheat stat for continuity, this can cause the fan to come on and go off and repeat the cycle.