Not sure what time it came on this morning, I slept right through to the alarm clock! Will test it over weekend and let you know if the reset solved it.
Honeywell CM927 - Optimised Start
- Thread starter Chris_J
- Start date
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Well, it's programmed for 20C @ 11am for Saturdays and it came on bang on 9am this morning. Looks like a reset doesn't do anything.
I noticed that the "factory reset" option in the parameters menu (which is what I used) only resets any settings you have made. It leaves the programme and I guess anything else in tact.
I think I'll try removing the batteries again, but leaving it overnight and see if that helps.
If not, then I guess I need to either turn off the optimisation function, as my hallway must get colder than an average hallway, causing it to fire up at the maximum 2hrs before. Or I need to adjust the times accordingly.
A bit annoying, but hey, it's still a very good stat.
I noticed that the "factory reset" option in the parameters menu (which is what I used) only resets any settings you have made. It leaves the programme and I guess anything else in tact.
I think I'll try removing the batteries again, but leaving it overnight and see if that helps.
If not, then I guess I need to either turn off the optimisation function, as my hallway must get colder than an average hallway, causing it to fire up at the maximum 2hrs before. Or I need to adjust the times accordingly.
A bit annoying, but hey, it's still a very good stat.
It is still learning - only had one day so far! Why not leave it until Monday and see what happens then.
According to the literature, all the settings are stored in EPROM memory. The battery is there purely to run the clock and the display.
Buy a Min/Max thermometer (about £10) and hang it next to the programmer, this will tell you what the temp goes down to overnight. You can then compare starting time with temperature to see if the optimization is doing anything.
I would be surprised if the hall cools down more than the rest of the house, unless there is a large single glazed window or door letting out all heat!. It could be that the radiator in the hall (no TRV I presume) is not large enough. Do you have a rad on the landing upstairs or is the hall one expected to heat the hall stairs and landing?
You don't say if you have TRVs on any of the rads or if the system has been balanced.
I should say that I have a CM927 with optimization turned on and it works like a dream; particularly the way it maintains the temperature virtually constant. I had a CM67 previously which was also very good, but not so user friendly. My son has it now in place of an old mechanical timeswitch and stat. He says things are much better now.
I'll leave it over weekend then and see if it improves.
There is just one short radiator in the hallway, which heats the small area, plus quite a small kitchen. There is another radiator on the landing upstairs. Thinking about it again, I doubt the hall is much colder. When the heating turns on, all rooms in the house seem to get warm at the same rate and stay warm. Plus, I've been downstairs early in the morning before the heating triggers and it's usually 16-17C and I've only programmed for 18C.
System is balanced, but I don't have TRVs. I just use the control valve to choke down the radiators in rooms where I don't need much heat or any heat at all.
There is just one short radiator in the hallway, which heats the small area, plus quite a small kitchen. There is another radiator on the landing upstairs. Thinking about it again, I doubt the hall is much colder. When the heating turns on, all rooms in the house seem to get warm at the same rate and stay warm. Plus, I've been downstairs early in the morning before the heating triggers and it's usually 16-17C and I've only programmed for 18C.
System is balanced, but I don't have TRVs. I just use the control valve to choke down the radiators in rooms where I don't need much heat or any heat at all.
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How do i turn on the "optimum start" option, says in the manual for the CM921 that the installer does this but mine isn't enables
You press the < & > & i at the same time to get into the engineers menu.
You then select option 8 and change the setting from 0 to 1 (enabled)
All the latest CMs are coming out with optimisation disabled as the default setting. It is easy to change, you need the white folded paper part of the instructions. Or download them from their website.
You then select option 8 and change the setting from 0 to 1 (enabled)
All the latest CMs are coming out with optimisation disabled as the default setting. It is easy to change, you need the white folded paper part of the instructions. Or download them from their website.
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