combi boiler hot water

[stuparry]

I have a gavina GTI-R 30 combi boiler.The problem is a distinct lack of hot water.The cold water pressure is fine ,being pumped to the house.The boiler fires up and reaches the corect temp.I have taken the pump off and had it checked and is working.Ihave drained some water from the boiler and this looks very clean.I have disconnected the hot water out -flow from the boiler to see what the flow is like ,but this seems about the same that i recieve at the taps.Ihave even taken off a mixer tap to see what the flow is like.No luck please could somebody advise? By the way the boiler is 4 years old

[Jonathan Pearson]

If your boiler has a mechanical diverter valve, then no hot water usually means that the diaphragm has worn out, you can check this by turning on the hot tap and over-riding the microswitch (usually moving it up with insulated screwdriver) on top of the valve and see if boiler fires up - only do this if you know what you are doing as you've got 240v inside

Jon

[Dave£]

If what you are trying to say is that you have poor water pressure at the hot taps and this water not as hot as it should be, then most likely, IMO, your secondary heat exchanger needs descaling (or replacing, if you prefer). Mine was near impossible to descale without special equipment. I ended up buying a new one.

Dave L (I am not a plumber)

[Ed Sirett]

I'd go with the scaled heat exchanger idea. Especially since the OP seems to imply there is poor flow aswell.