John Rumm wrote:
F wrote:
On 19/10/2009 13:14 Jim wrote:
FW100 Weather Compensation Controller 7716192067

Seriously expensive. Is there any advantage other than a comfortable
temperature a litle earlier?

It won't get there any sooner, it will just do it more consistently and
with less overshoot.

It can't pay for itself.

Can it?

Eventually - it will reduce the gas usage a bit and improve the
condensing efficiency of the boiler a bit. I calculate on gas bills like
mine it could save about £100/year. So on a DIY install, payback in a
couple of years perhaps.

You haven't accounted for the saving of not having to buy separate
timeclocks and thermostats: a decent digital thermostat will set you
back about this much anyway.