I have had the error F25 appear on my boiler and as a result have filled it with water to raise the pressure levels to between 1 and 2. However after 15-20 minutes the pressure level is back to zero and the error F25 is on screen again. I have checked that all the radiators are hot which they are and cannot see a visible leak. Please help!
check pressure release valve pipe going from boiler through the wall to outside 15mm pipe, see if it is passing water and also check the pressure in your expanssion vessel if water cums out of the valve it nakered
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