"rob" wrote in message
...

"Richard" wrote in message
...
Can anyone help please?

I'm totally in the dark when it comes to central heating systems, so any
help would be most grateful.

Swift Flow 80 Combi Boiler with Honeywell control.
The problem is that I can only get intermittent hot water supply through
the
taps, sometimes it comes through hot but most of the time it's cold.
However, if I leave the central heating on, or switch it on, the hot
water
is fine.

The system is approx. 5yrs old. It's never been serviced (to my shame,
probably why I've got problems now) I had to replace the fan impeller
and
motor a couple of years ago.

Water pressure gauge seems ok

Thanks,
Richard


I have just had the same problem with my c/heating boiler. Ravenheat
(bagsh1te)
This was the diverter valve.
Inside the valve there is a rubber diaphram, which can be replaced
usually.
I replaced mine with another used one as a temp job, but the rest of the
valve had seized,and I have had to replace the whole valve. cost me about
£130. diaphrams are about £18-£30.
This is not a job for a novice, however seasoned diy'ers could do it ok ,
with the correct knowledge.
Because my boiler had had no work on it for 4 years, when I came to do the
job, I got leaks on the pump, through vibrations when taking valve out.
Had
to get new pump seals. also the isolation valves started to leak and I had
to replace them too..
Look on the web for cheaper valves, I found out later, the valve was £55
p/vat on the web. Havent had chance to call them to check if this was the
same valve. gutted when I found out.


£45 + VAT at BES.