Dual controls but downstairs cold

[hertsman]

Hi - please help me wth a problem, and would like some advice.

I have two thermostat controls for my CH. One upstairs and one downstairs. The theory is that the upstairs and downstairs rads can be set to come on at different times, all running off one combination boiler. And it works fine.

The downstairs controller needed a new battery which was changed. Since then, the downstairs rads are cold. Upstairs is fine, and hot water is fine.

Is the "downstairs controller battery" problem the cause of this?

Or is it a red herring and maybe hiding a more serious problem?

Thanks

 

[Registered Gas Man]

What make is the controller?

Is it RF?

If so maybe it needs re-binding?

 

[past3bar]

You have 2 x 2port valves somewhere?
Sounds like one may be stuck.
Hope you have a by-pass on this system.

 

[hertsman]

Both thermostat controllers are made by Horstmann (the boiler is a Potterton)

Sorry, don't know what you mean by "RF" or "re-binding" (my fault - I'm not technial!)

I had a look where the boiler is. There are four pipes coming out, two for upstairs and two for down. Each pair runs through a switch-type device, so that could be the "port valve" you ask about? There looks to be a small lever at the back of each of these.

 

[Registered Gas Man]

Stupid question but are the batterys in correctly?

RF = Remote frequency = wireless

If your timer is working it will send a signal to the switch type things or zone valve. You can confirm that the switching is taking place by trying to move the lever that you speak of. If the timer is calling for heat and the zone valve is electrically open then if will offer no resistance when moved. If the timer is definaltey working and the zone valve offers any resistance on that lever you can safely assume your problem lies in this area.

A quick solution, until you can get someone to check it out is to manually lock open the zone valve. The lever can be locked in the open position, downstairs will now get warm when upsatirs is on.

 

[hertsman]

Thanks for your replies. They were very useful.

I found the two switches and pushed the one for the downstairs circuit. It was a bit stiff, but then the rads started heating up fine. I reset the downstairs controller and reseated it, then re-programmed it. All working fine now, but I do have a knocking noise everytime it comes on. The downstairs "switch" is a bit stiffer than the other one. Is that what will be causing the knocking noise?