In article .com,
writes
Hi,

My Vokera Excell 80 SP boiler will heat the radiators, but it doesn't
seem to know when the taps are switched on, as such the hot water
doesn't work.

I have checked the pressure, and it's about 1.5bar.

Can anyone suggest how I might troubleshoot the problem further?

This boiler gets mentions here quite a lot so you could do worse than
doing a google groups search for it.

The installer manual for it has good fault finding flows and is available from
http://www.vokera.co.uk/ (needs flash), head for Installer Product Info
Discontinued Products. Reading this will let you know what bits are where
and guide you through a fault finding session.

The flow switch would be a prime candidate and easy to check, disconnect
power, turn on tap and check for operation of the switch using a multimeter
on ohms/continuity. Next best is probably the diverter valve, check back at
previous posts as this is mentioned there. Finally, the soldered joints on
the pcb for the H/W (and C/H) temp control are prone to failure, an easy
job to re-make them if you can solder but leave that option til last (if
wiggling the spindle causes a momentary spring back into life then this is
a good bet).

This is a pretty simple boiler so is a good candidate diy but watch out for
live parts and don't touch gas carrying parts unless you are competent.

Oh, also see the Gas-News forums:
http://www.gas-news.co.uk/discus/mes...tml?1124134482
They are pretty trade oriented so may be less likely to help an amateur but
there is a lot of useful existing content.

Good luck.
--
fred
Plusnet - I hope you like vanilla