Best setting/efficiency for programable thermostat (CM927)?

[wrighty208]

Hi,
I've recently bought and fitted a Honeywell CM927 wireless programable thermostat (that i'm very happy with by the way!).

I have a standard open vented gravity system (Y-Plan) with an old back boiler in the living room.

I'm just experimenting to find what the most efficient settings of the thermostat are and whether it's best to leave the heating on all day/night at lower temperatures or leave off when not needed.

I currently have the boiler on setting 3 of 5 (not sure of the temps - old baxi back boiler!), I have all the TRV's set at number 3 (about 21 degrees I think) except the hall when I don't have a TRV (as I have the thermostat there! and I have the hot water tank stat set at 60 degrees.

What do you think would be the best settings on the programable thermostat considering I'm generally up at 6:30 and off to work by 8am returning at 6pm and off to bed about 11ish? Also so I have the optimisation on or off (I have it on at the moment and it seems to work very well - just not sure if it's costing me a lot more money!)

Thanks for any opinions!

 

[Chris_J]

The most efficient way to heat your home is to only heat when you need it, and as much as you need it. If you program your stat to keep your home warm when you're not there, you're wasting money.

As you say, the Honeywell CM927 comes with an optimisation setting which will calculate the best time to switch the heating on in order to achieve your desired room temperature at the particular time you set.

So, if you generally arrive home for 6pm and like to come home to a warm house, then simply set eg. 21C for 6:00pm (or possibly a bit later if it doesn't bother you and want to save more pennies.) The stat will do the rest of the work by monitoring the room temperature and working out when it should switch on to achieve 21C @ 6pm.

This then means there is absolutely no need to leave your boiler on low 24hrs a day, wasting energy and wearing your boiler out. The stat will run the boiler for the minimum amount of time possible to suit your needs.


One thing I can't answer, and I'm wondering myself is temperature settings. I'm not sure whether it's actually more energy efficient to turn the boiler up to maximum, making it work harder to satisfy the stat, but then of course being able to switch off earlier. Or turn the temperature down so it's just high enough to achieve the highest temperature setting on your stat. Not sure...