I have a potterton promax combi he plus showing error code e160. Dont have the manul to see what the problem is.

SOURCE: Error Code F-20

I have same machine and manual says, "F20" on display (water inlet problem - no water or insufficient water supply). Select STOP twice to cancel the cycle. Unplug washer or disconnect power. Check the following. Are water faucets completely turned on? Are screens at inlet hose connection to washer clogged? Are water inlet hoses kinked? Are water inlet hoses frozen? Plug in washer or reconnect power. Re select cycle and press START. if the problem remains, call for service.

SOURCE: Baxi/Potterton wall hung fan assisted combi boiler

does the boiler come on when the hot water tap is run if not change the hot water flow switch or the diaphram in the hot water flow valve it may be split

SOURCE: fitting room stat

take the link out and fit stat wires in its place,will work then.