Dave Liquorice wrote:

On Wed, 03 Oct 2012 22:56:31 +0100, Andy Burns wrote:

I use my boiler (ancient cast iron lump with pilot light) for hot
water all year round, on timer twice a day with tankstat and plenty
of lagging

I bet if you switched from the twice a day time switch to "on demand"
it'd make a noticable difference to the gas used.

Even noting the correction from £1/month to 37p/day, I don't think ICBA.

I found that out when the mechancical time switch failed. Didn't
immediatly replace it, I was living on my own at the time and to heat
the cylinder from stone cold was only 30 mins or so.

I don't know how long the boiler runs for each day in summer, but I'd
guess it's about 1/4 hour morning and evening (I should hook-up a
monitoring script to the networked thermostat).

Just bung it on before I wanted a bath, it would be hot again by the
time I was finished to switch it off. The tank was well lagged and
would remain hot enough for washing up/washing for at least 48hrs.

But I don't want to get up half an hour before I want a shower ...