what is wrong with my boiler?

i have a potterton puma 80e, light tells me low pressure but, pressure up to 2bar, fan not running, changed fan, no good light still sats low pressure even up to 2 & half bar, dont seem to be getting live from fan connector but could be 12v & not reading on a neon, can you help??
peter, January 2005


done
the problem is the low water pressure sensor, i would say it is blocked or where the sensor conects to the pipe its is blocked there. the sensor is located behind the pcb housing by the pump, to the left i think, it will have 2 wires conected to it i think they are yellow. you will need to electricaly isolate the boiler and drain down the ch water, when you take out the sensor there should be hole inthe bottom about 3mm across you need to unblock it, also check the connection while your at as that may be blocked also.

P D, August 2007
remove front cover look behind circuit board carrier (that swings down when 1 screw at top released) you will see a small circular sensor with 3 connections on it only two of them used, this is the low water pressure sensor, remove one wire and the if the boiler fires up and the heating works, you need to change the sensor. never run the boilerfor any length of time with it disconnected as it could run dry ( very bad ) sensor is cheap and readily available.

dom, January 2005
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