The pressure on the hot water in our house feels like it's gradually getting worse. I'll try and take some measurements over the coming weeks/months to confirm, but I was wondering if anyone had any thoughts on what it might be, and anything that I can could try in the meantime. It's a combi boiler (Worcester bosch greenstar 25i from memory) Cold water pressure is absolutely fine. I think it's affecting all taps in the house, perhaps not the kitchen tap (but that's always had a lot better pressure than the rest of the house).
How old is the boiler and has it been regularly serviced ? Could be a simple blocked filter ,or if very old and neglected something worse. I assume you mean a lower flow rate ,as opposed to pressure.
Are all isolation valves on the cold pipe to the boiler fully open including the one on the underside of the boiler? Definitely be looking at the filter in the water flow switch. If that’s ok then the plate heat exchanger.
Test taps... Run in a bucket and see how long it takes. Time... Try with hot water turned off but run the hot water tap so cold water comes out then do the same with hot water on. Is there a difference in time it takes to fill bucket?
Yes. Not sure how to turn the hot water off without turning off the boiler entirely. But I tried it with the boiler turned off and it's the same time as with it on; 19 seconds to fill 1.2ltr pot. For reference it takes 9 seconds for the cold to fill up the same pot.
Can't be a hot water problem then.. More flow or pressure as the cold don't go through the boiler.. As for turning off hot water.. Should be a knob on boiler.. Heating and water... Just water and all off. Normally a pic of a tap and radiator
My boiler looks like this: In the central dial I set the hot water side to 'off', but I think all that does is turns off the feature to have a bit of hot water ready as soon as the tap comes on. With this set to 'off' the water still gets hot, but it just takes a few seconds to do so. The fact that it still performs the same with the boiler turned off, are you saying it can't be the heat exchanger or filter as others have suggested? It affects all taps but they vary in age from 2 years to 2 months so don't think it could be that. We did install a new bathroom a couple of months ago, but it was a like for like replacement and the only thing that changed was the taps and tails. Could something have happened during installation that could've caused this? Again it's affecting all taps in the house, not just the two new ones.
Just a quick update in case anyone else has the same issue. It was indeed the heat exchanger. £250 for parts and labour.
Feedback is always good for all peoples ! Sometimes using the correct words help, ie, my flow rate is poor, rather than my pressure ie poor . Good luck Regards Peter