In message , altheman
writes
hello, this may a stupid question to some but to me it is not...i have
recently moved into another house...the current central heating system is
run with a ...RANDALL 4033 PROGRAMMER....it has 2 switches...one that
controls the hot water...the other controls the central heating (
radiators)...what i can gather the PROGRAMMER is approx 20yrs old...but
still seems to work perfectly...my question therefore is....do i need to put
both switches down to run just the central heating ?..for just the hot
water i only put 1 switch down...but someone said that to run the radiators
i had to put both switches down...even if i only wanted radiators on and NOT
hot water,we also have a BAXI gas fire with a back boiler ( if that is of
any importance)..many thanks in advance


Probably yes, if this is an older system, as it sounds like.

My current system is like that - waiting to be upgraded next year. The
HW is a gravity circuit. This means it circulates just because the HW
rises from the boiler in the pipes. There should be pump pumping water
around the heating system. My timer is such that you have to have both
the HW and CH on to get the boiler to fire

I plan on upgrading to a fully pumped system probably next year.

--
Chris French