"Brownie" wrote in message
...
I did Google prior to this post but was a bit confused by a variety of
answers.

I have a gravity fed CH system with standard boiler with a programmable
timer.

I assume that your central heating is pumped.

Do you have a 'gravity' hot water system, typically with 1" diameter pipes going
from a floor standing boiler to hot water tank, or a fully pumped system
typically with a wall mounted boiler?

In the former case you might want to consider the Danfoss TP9 which would
replace you existing programmer and thermostat. Last winter I could not find any
exact competitors. The unit comes in two parts, programmer and room temperature
sensor. I bought one, and it works well in this situation.

In the latter case you can probably consider replacing the existing room
thermostat with a programmable uint such as the Honeywell CM67. You would leave
your present programmer CH on all the time, the CM67 would call for heating
according to your temperature profile. There are a number of competitors.

In either case you can download the installation instructions from the
manufacturers web sites. If you can follow the instructions, it is not a
difficult DIY job, if not, you may be better finding a suitably qualified person
to do the installation for you. The modern electronic progammable thermostats
typically provide a more precise temperature control than the old mechanical
ones.


Michael Chare