I have a potterton Puma combi boiler around 5 years old. Since the guarantee ran out the kitchen rad has not worked at all - checked TRV - all ok. Recently the rads have been going off if taps in bathroom are not turned off really tightly. But tightening them has turned rads back on. When a bath is run the heating goes off completely. In the last few weeks I have had the low pressure light on - this has been remedied by turning the valve under the boiler. Now I have only hot rads upstairs!. I have tried turning them all off and then on again - one at a time- starting downstairs,. This was ok for about half an hour and then the downstairs ones started getting cold again. Please help me - this causes so much frustration in the house - I may soon need marriage guidance!!
Help - heating driving me crazy
- Thread starter smallwood
- Start date
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You may have a hidden leak somewhere causing the loss of pressure. An airlock may have thus got in and stopped the downstairs circuit. How old is the radiator system? Another possibility is pump failure and the upstairs rads may still work by gravity. If this is the case you probably find the upstairs rads get hot even when the central heating is turned off for the summer.
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The divertor valve in a combi boiler system acts to divert the heat energy either to DHW (domestic hot water) or to CH (central heating), but not both.
The design is such that a demand for DHW takes priority over demand for CH. This is mostly because very much more heat energy is needed to 'instantaneously' heat cold water to a usable temperature at the tap than is needed to gradually raise the temperature of circulating CH water. It's this priority that causes CH problems if a hot tap is left dribbling.
Also, one of the many failure modes of a divertor valve results in CH water not being heated.
If the DV is faulty, although replacement is not technically difficult, you need a fair amount of general knowledge about heating and plumbing to tackle it safely and successfully, so you should consider paying a heating engineer to diagnose and fix the fault.
The design is such that a demand for DHW takes priority over demand for CH. This is mostly because very much more heat energy is needed to 'instantaneously' heat cold water to a usable temperature at the tap than is needed to gradually raise the temperature of circulating CH water. It's this priority that causes CH problems if a hot tap is left dribbling.
Also, one of the many failure modes of a divertor valve results in CH water not being heated.
If the DV is faulty, although replacement is not technically difficult, you need a fair amount of general knowledge about heating and plumbing to tackle it safely and successfully, so you should consider paying a heating engineer to diagnose and fix the fault.
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