Myson
Midas B
| Problem | Solution |
| Overheating | 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. |