Hot Water Problem

[RgR]

I have a Volkera Maxin 24e combi boiler. The heating works fine, but the hot water only starts to flow when the tap is open fully. I have had a look behind the front panel, and noticed a pin which very slowly emerges from a brass housing, to depress the micro switch, which fires the boiler. Unless the flow of water is very fast, it emerges and then stops about half way of its travel. The only way to have it come all the way is to open the tap fully. If somebody takes a shower and it is out for a great length of time, it is more reluctant to come out afterwards, even with the tap on full. It does however improve if it is left for some time. I have seen other messages which mention a dhw diaphragm. Where is it located, and is it easy to change ? This is if you think this is the problem. If not, have you any other ideas ?

Thanks in advance.

 

[gasgeezer]

open the tap if you can push the pin back usually indicates diaphram has split in it

 

[RgR]

O.K. tried this, and its strong. I can't push it back at all.

 

[Agile]

I would still say the diaphragm is failed although the pin may be dirty causing it to stick halfway in the gland.

Its probably leaking at the gland as well if the pin is dirty.

We would charge £106 inclusive in the London area. I view them as tricky but not difficult and we would allow 1.25 hours which includes a service and performance check.

Tony