Hi, wonder if anyone can help, I have a Potterton Puma 100e which is a number of years old now and has always been troublesome. My new problem is that no hot water or central heating can be got from the boiler. When a hot tap is opened a restricted flow can be heard through the boiler but it wont fire up. The only light lit on the control panel is the mains light. The red light on the modulater board lights when the hot tap is opened. Following the fault finding process in the manual all voltages are present and the manual says change the fan but I have bench tested the fan and it runs fine. The relays open and close when the boiler standby switch is operated. When the c/h switch is operated the fan can be heard running and the pump runs. There is one bar preesure shown on the dial and gas and water supplies are present. Anyone any ideas on fault finding this very troublesome boiler. I have also replaced the DHW flow switch and micro switch.
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