How much power does my thermostat use?

[Martin Pentreath]

Hi,

As winter seems to be arriving, I'm finally going to install my Honeywell CMT927 (wireless programmable thermostat) this weekend. I'm an incorrigible miser when it comes to electricity (delighted now that carbon footprints are all the rage, I can hop on that bandwaggon, but my stinginess has nothing as noble as environmental concern behind it). Anyway, I was going to just take the power feed from the same FCU as the boiler. But it has occurred to my parsimonious mind that it's pretty wasteful having the thermostat running for six months of the year when it's not doing anything. So I'm inclined to give it its own FCU so I can turn it off next spring, but does anyone have any idea how much power these things actually use? The documentation that came with it doesn't say, and I can't even find the thing on Honeywell's website.

Cheers!

Martin

[John]

Get a life - there are more important things to worry about - like people buying stupid outside Xmas lights from China every year so they can enjoy Xmas.

I guess the answer is 'negligible'

[John Rumm]

Strap it to your hot water cylinder so all that energy is not wasted in the summer.

[<me9]

The electronics will take next to nothing. the main consumption will be the actual switching relay when actuated, This is unlikely to be more than a watt, and wouldn't be consuming power when the heating is off.

[Dave Liquorice]

The amount of energy you save by using it (sensibly) will far out strip the amount of energy it will consume for the entire year.

Even if you say it takes 5W (unlikely) thats only 43.8 kWhrs/year or about the same as an average boiler running for 2hrs.

[John Rumm]

If you use an impulse relay (as used by the battery powered prog stats) then you will only take power as it switches.

My prog stat is about 4 years old, and still on its first set of AAs.

[geoff]

In message , Martin Pentreath writes

Switch it off when you're not using it then

ha ha