I have one of these:-
Works OK, but it will not allow independant hot water/heating, just both together and therefore I want to fit a different kind, which I already have.
Problem is that I can't manage to release it from its sub-base which is mounted on the wall - the manual says that, "it can be removed if required by depressing the locking catch with a screwdriver".
All fine and dandy, but where is the locking catch ?
Thanks.
Don't know this particular model, but it's usually underneath. Some (presumably not thi, as it says 'catch', but you never know) have a small recessed screw.
Look for a hole or slot underneath into which you can poke a thin screwdriver or thick paper clip.
Apart from how to get into the unit, isn't there an apparent question about the system itself?
If the Honeywell won't control DHW and CH seperately, a replacement is unlikely to do so, because the fault lies in the controls available to the programmer, not the programmer? A lack of control valves to be turned on and off?
Just an idle thought and probably wrong.
No, the problem is purely with the programmer - the system can happily do hot water or heating or both, manually. The programmer simply cannot operate the two individually.
The message from Neil Barker contains these words:
I have no knowledge of that particular programmer but programmers traditionally have been designed to work both with fully pumped and pumped central heating/gravity driven domestic hot water systems.
Given that your programmer won't cooperate has it been set for gravity DHW?
Not quite sure what you mean by not allowing independant control - as it's precisely designed for this. But of course depends on other things. If you have gravity circulated hot water heating circuit for example you can't have heating only.
Look for a tiny slot in the bottom corner.
Then it's wired up incorrectly. It does precisely that here. Unless you want different on off times.
Can you please define what you mean by "individually". The programmer has separate sliders for CH and HW - each of which can be set independently at off, once per day, twice per day or constant. What does it *not* do?
To answer that myself, maybe you want to time both the CH and HW but have them going on and off at *different* times from each other? If that is the case, this programmer *won't* do that, 'cos it's only got one timer. You would thus need to replace it with one having *two* independent timers.
OR - and possibly a better solution - replace your room stat with a programmable stat. You can then leave the CH control on your existing programmer set to 'constant' and do the *actual* timing on the programmable stat. This has the advantage of being able to select different temperatures for different times of day (or different days of the week if it's a 7-day jobby) as well as things like providing an automatic frost stat (and usually other goodies too).
That's correct and what I want to do - e.g.
Heating 6am-7.30am, hot water 6-7am. Heating 4.30pm-10pm, hot water 5pm-6pm
I already have another digital timer that can do this - just need to remove the old one first, hence the original question.
Thanks for the suggestions all.
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