How can I fix the low pressure on my Potterton Puma boiler?
My boiler often drops in pressure and the red low pressure light comes on. I usually turn the black tap to let in some water and its ok again. I have had 2 plumbers out to fix this before and it has now gone again. The gas in the boiler is lit but I cannot get the low pressure light to go off so have no hot water or heating.