Replacing Potterton Room Stat

Jeremyb123 · Posted: Tue Jun 12, 2007 3:50 pm

The existing Potterton room stat has stopped working, and when the radiators come on they are boiling hot.So when I\\\'ve gone to replace the stat, I\\\'ve noticed that the existing one , as well as live & neutral, has a H for heating, which my replacement does not have, it just has a terminal for L & N, the three, numbered 1,2 & 3. Do I need to replace the stat with a Potterton like for like ?

gas4you · Posted: Tue Jun 12, 2007 5:16 pm

Neutral will remain the same, Live will be live from programmer/timeswitch and the 'heating' will be the switched live from the new stat back to the zone valve or pump. Instructions with new stat should tell you what switched live is.

ricicle · Posted: Tue Jun 12, 2007 5:49 pm

The room stat does not control the temperature of water in the rads.That is the job of a stat on the boiler.

Jeremyb123 · Posted: Mon Oct 22, 2007 2:08 pm

gas4you wrote:

Neutral will remain the same, Live will be live from programmer/timeswitch and the 'heating' will be the switched live from the new stat back to the zone valve or pump. Instructions with new stat should tell you what switched live is.

Thanks.
I've replaced the stat with the Potterton model the supplier said, so all works fine....... except that whenever I put the hot water on, on it's own, the radiators come on as well ????

Steve3948 · Joined: 10 Oct 2007 Posts: 152 Location: United Kingdom

ricicle wrote:

The room stat does not control the temperature of water in the rads.That is the job of a stat on the boiler.

It does control the temperature of the water in the rads by opening and closing the 3 or 2 Port Valve.

The boiler stat controls the temperature of the water in the main flow and return.

Steve3948 · Joined: 10 Oct 2007 Posts: 152 Location: United Kingdom

Jeremyb123 wrote:

gas4you wrote:

Neutral will remain the same, Live will be live from programmer/timeswitch and the 'heating' will be the switched live from the new stat back to the zone valve or pump. Instructions with new stat should tell you what switched live is.

Thanks.
I've replaced the stat with the Potterton model the supplier said, so all works fine....... except that whenever I put the hot water on, on it's own, the radiators come on as well ????

This could be a 3 or 2 Port valve problem, with a micro switch stuck or broken, unless it's a combi.

Do you know what system you have, Combi, Y-Plan, S-Plan, C-Plan ?????