Combi boiler, no HW upstairs only

[GasmanxxxR1]

I mainly do installs but a good friend of mine called with the above symptoms. Any ideas as to what i should look out for?

Many thanks

 

[diamondgas]

Stretched diaphragm on the hot water flow valve, reduced flow, filter blockage. That sort of thing Sounds like its detecting flow but not all. If it's the shower then that can be different all together

 

[GasmanxxxR1]

Yes they said the shower was the first thing they noticed, any ideas, thanksdiamond gas

 

[CES]

Are they getting HW at other outlets (i.e. Kitchen), Are they getting water at all upstairs? If its just upstairs affected its probably a pipework/tap issue.

 

[GasmanxxxR1]

They said upstairs only is affected, wife said shower, husband said all the hw outlets upstairs

 

[CES]

its one of those jobs you would have to see for yourself in order to diagnose it. Sounds more like a plumbing problem than a boiler problem IMO.

 

[diamondgas]

Most likely stretched diaphragm ... Do you know what boiler it is? The shower stat cartridge is possible but I'd want to eliminate the boiler TBh much cheaper

 

[GasmanxxxR1]

Thanks for the great advice. How does the stretched diaphragm cause those symptoms?

Must go on that fault finding course

 

[diamondgas]

Certain flow rate required to produce the pressure diff to lift the diaphragm. As it stretches it takes a greater diff to lift the valve. Upstairs will have a lower flow rate than downstairs, shower even less! Eventually the stretching will get to a point where the lower requests will be ignored. Usually shower then upstairs basin....!

Does that make sense?

 

[GasmanxxxR1]

Yes, thats brilliant diamond gas. When i get stuck into it, i love fault finding. Its just been years since had to fault find on a boiler. I now mostly fit new and fault find on the system, if you know what i mean

I really do need to go on a refresher course and earn some money this way...

Any courses to recommend?