I've just bought a new Honeywell CM67 Room Thermostat to connect up to
my ancient (20+ years old?) Potterton Kingfisher CF55 (open flued, gas
fired).

I'm planning to replace the boiler in about a year, but before I
install & configure the new thermostat, I want to check that I'm not
doing anything that might upset the boiler. I'm particularly thinking
of parameters like 'Minimum On Time', 'Cycle Rate' and 'Proportional
Band Width'

Any advice on changing those settings for an antique boiler would be
much appreciated.

Michael

In an earlier contribution to this discussion,
wrote:

I've just bought a new Honeywell CM67 Room Thermostat to connect up to
my ancient (20+ years old?) Potterton Kingfisher CF55 (open flued, gas
fired).

I'm planning to replace the boiler in about a year, but before I
install & configure the new thermostat, I want to check that I'm not
doing anything that might upset the boiler. I'm particularly thinking
of parameters like 'Minimum On Time', 'Cycle Rate' and 'Proportional
Band Width'

Any advice on changing those settings for an antique boiler would be
much appreciated.

Michael

I don't think it's an issue. If you're replacing an old manual room stat,
that won't have had any of these niceties! The boiler should be able to cope
with anything you throw at it.

If you've got a gravity HW and pumped CH system - as seems possible - the
CM67 won't control the boiler directly anyway - it will control the pump,
and the boiler will cycle on its own stat.
--
Cheers,
Set Square
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On Tue, 13 Dec 2005 13:17:31 -0000, Set Square wrote:

I don't think it's an issue. If you're replacing an old manual room
stat, that won't have had any of these niceties! The boiler should
be able to cope with anything you throw at it.

The only warning I've seen is in relation to the propotional control.
It's not recomended to use that if the system uses motorised valves.
Each cycle of the proportional control also cycles the valve. Normally
6 times per hour, rather more than the conventional system of open
when cold close when hot...

If you've got a gravity HW and pumped CH system - as seems possible
- the CM67 won't control the boiler directly anyway - it will
control the pump, and the boiler will cycle on its own stat.

Hopefully with some form of control to stop it firing just to keep the
gravity loop warm.

--
Cheers
Dave. pam is missing e-mail