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Honeywell CM907 - No heat!

Postby mclb01 » Mon Dec 27, 2010 5:35 pm

EDIT - sorry I posted this thread twice in error. Please delete one of the threads.

Hi all - hope everyone had a nice Xmas!

Help - I have no heat! I have a Honeywell CM907 7 Day Prog Thermostat (installed by qualified Electrician) controlling my Alpha CD32C combi boiler and heating system which was all installed around 3 years ago (by Corgi installer). As of today, the CM907 is calling for heat but my boiler isn't firing. The boiler is fine as it fires when I turn on the hot water and the heating worked yesterday. I've checked the boiler pressure and this is fine too.

Not sure if relevant but over the last few months some of the buttons have stopped working on the CM907 (Time change, copy day, day select, program buttons, OK button etc). I don't know why this has happened?

I can only assume at this stage that the CM907 is at fault as it is calling for heat but for some reason this signal isn't getting through to the boiler?

I've contacted the Honeywell helpdesk (closed until 4th Jan) and the installer has gone away skiing and I therefore have 2 questions to you good chaps:

1. Does anyone have any ideas what this could be?

2. Is it possible to manually fire up the boiler in the meantime, i.e. independently of the thermostat calling for heat?

Thanks in advance.
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Simply Build It

Postby stoneyboy » Tue Dec 28, 2010 5:37 pm

If you have a motorised valve controlling the heating you could try operating the manual lever and see if the heating will come on. Beyond that you are into fitting a shunt to the terminals of thermostat.
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