wrote:
On Sep 16, 12:54 am, John Rumm wrote:
Robin wrote:
Unfortunately, there is no room thermostat. At least not as far as I
can see. I'm going have a longer think about this and see what my
other options are. As another poster commented, there are some issues
with my simple plug timer plan.
In which case this seems like an ideal opportunity to add one.
Generally very easy to do. If you don't fancy running a cable to the
stat position then you can even get wireless stats.
Thanks. I'm going to pursue this a bit.
Now I just need to find out what the (undocumented) 25 year old control
panel is doing.
If you can get the existing control panel to set the boiler to run
continuously, then you can let the prog stat do all the work from there.
The timer becomes in effect redundant (although no harm in leaving it
there in circuit)


If I understand the system correctly, that control box will control
the temp of the primary circuit. If this is so, then removing it,
wiring over its temp limits or setting the boiler to run continuously
would all be most unwise.

Ideally you want a timer & thermostat to control the supply that feeds
the main jet gas valve in the boiler. Most likely you need to design
your add on wiring from the ground up, ie think about exactly what
youre trying to control and wire things up to do that, WITHOUT
removing any of the key safety devices, such as the existing control
box's primary circuit temp control.

You'll only know for sure by looking for all electrical parts inside
and outside the boiler, and working out which does what. Until you can
be sure, it is not appropriate to remove what are likely to be safety
components on what looks like a crude system.

The original purchaser saved themsevles a few quid by not buying the
timer... I wonder how many times over that saving was gobbled by extra
fuel.


NT


Well...

The real odd thing is that I do have a timer!

It was connected to the boiler, not the "control box" (by control box I
guess you mean the picture of the thermo nuclear device).

For your amusement, I've uploaded a picture of the timer connected to
the boiler. I've removed the plate that covered these connections.

http://www.flickr.com/photos/7204575@N04/2866071656/

On the terminal block, the timer is connected to terminals 7, 8 & 9. The
rating is 20v (obscured by the timer cable).

In the manual for the boiler, (and also on the cover plate for the
terminal block), it says "Do not use Terminals 7 to 12". !

I'll open the control box up at the weekend and see if there is anywhere
obvious to connect the timer.

Many thanks for all the comments.

- Robin