Looking fora tank thermostat with a built in timer

I've recently replaced a Honeywell T6360 thermostat with a CM907
Chronostat and I am generally very happy with it.
There is one downside though. To give total control of the heating
over to the CM907 the main programmer/timer unit (a Potterton EP2001)
has to be set to continous for the heating. Due to the restrictions of
the EP2001 this also means that the hot water has to be set to continous.
If fact the act of setting the heating to continous on the EP2001 causes
the EP2001 to set the hotwater to continous too.
So what I'd ldeally like is a tank thermostat with a bult in timer as
for much of the time we don't need hot water but would still like a
warm house!
The system is a pumped Y plan BTW.
Any pointers?
-- --------------------------------------------------------------------
Guy Dawson I.T. Manager Crossflight Ltd
Reply to
Guy Dawson
Instead of taking the live feed to the CM907 switch (pin A probably) from the timed "CH on" pin of the EP2001 (pin 4 I think) why not take this live feed from a non-timed, permanent live?
Then the timer applies only to the HW and the temperature profile of the CM907 takes care of the timing for the CH.
Reply to
John Phillips
That would involve running new wires. The boilder and controller are in new extension (well, new in 1990) while the CM907 is the original (and current) hall.
I guess if I would rewire the switched live at the EP2001 to be a non-switched live then this might be enough.
Guy, who feels guess is not good enough! -- -------------------------------------------------------------------- Guy Dawson I.T. Manager Crossflight Ltd snipped-for-privacy@crossflight.co.uk
Reply to
Guy Dawson
Yes - that's exactly what I wanted to suggest. Sorry if it wasn't clear which end of the thermostat cable I was writing about.
It should just need the thermostat switch wire moved at the EP2001 from the "CH on" pin (pin 4 I think) to the L pin (or pin 5 if the installer link from L to 5 is there). BTW I'm going on a diagram from the web so please do check your EP2001 documentataion for correctness and safety.
Of course a programmable cylinder stat would also do if available, but the above seems simpler if it can be safely done.
Reply to
John Phillips
You should be able to set the CH to continuous and the HW to once or twice.
You may need to reset the device and/or move a mechanincal interlock and/or move a jumper from Gravity/10 to Full/Pumped/16 .
Reply to
Ed Sirett
There's my main problem - no documentation for the EP2001.
-- Guy
Reply to
Guy Dawson
formatting link
's an installer and a user guide.
I see Ed S. suggests it can be put into separate HW and CH control mode by switching from 10- to 16-program mode. See the installer guide section 12. Note that this seems to be done with the battery disconnected (see section 13).
If so, that would be an easier solution still ...
Reply to
John Phillips
In message , John Phillips writes
IIRC, the 10-16 selector is a mechanical interlock on the rear of the programmer, ... screwdriver and a 90 degree rotation
Reply to
In message , Guy Dawson writes
What do you need to know about the 2001 that isn't on the back of the programmer ?
I prolly have a user guide somewhere
Reply to

Site Timeline Threads

  • Following the recent flooding, we are thinking of buying a pump so that we can...
  • previous in

    UK Do-It-Yourself

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.