220 Code:  AC 220V no connection

Generally, JP Combi Heater supports the AC power 220V±15%. 

If your JP Combi Heater LCD switch shows a 220 code, the advised methods are as below:

1) Check the connections: 

Yellow-green is the ground wire;

Black wire is the neutral wire;

Red wire is the live wire.

If the wires are connected correctly and the 220 error still shows, then try to second method.

2) Disconnect the 12V and 220V power on the heater and press the button (below) several times. Make sure to press it hard so that the button is reset. You can use a tool to press it. Your finger may not get through it.

For those Silent Combi units, there is no RESET button to press. The solution is to release the extra hot water from the tank/boiler and run the Ventilation mode to cool down the temperature of the boiler. The error code should disappear soon.