Dual Zone Heating, wrong radiators coming on

[Graham27]

I've just moved into a new build property with a dual zone heating system. The downstairs thermostat is meant to control the downstairs radiators and the radiators to upstairs bathroom and ensuite. The upstairs thermostat is just meant to control the bedroom radiators.
When the downstairs control is on (and upstairs off), the raditator in main bedroom heats up (no other bedroom radiators heat up), but not the radiator in the ensuite.
When the upstairs control is on (and downstairs off) the radiator in the main bedroom does not het up on, but the radiator in the ensuite does.

Does this mean that there is a problem with the pipe connections, or could there be some other reason ?

 

[oldbutnotdead]

Most likely a wiring error but in a new build could be anything. Get onto the site manager or the builder.

 

[terryplumb]

Sounds like it's the way it was set up ,rightly or wrongly.

 

[Graham27]

Thanks for your replies. It is certainly not working as it should. I'm wating for the site manager to get back to me.
Are you able to explain how it might be a wiring problem ? I would have thought that if, for example, the downstairs control was opening the valve for upstairs, the water would flow to all the upstairs radiators not just one.
I'm just trying to understand so I don't get fobbed off by the builder.

 

[Graham27]

The pipework runs behind the plasterboard, so I assume that if it has been plumber incorrectly the builder will have to open this up ?

 

[martygturner]

No just swap the thermostat wiring in the wiring centre...

 

[terryplumb]

If your issue is that some radiators are not on a zone that you would like them to be on ,then swapping wiring or thermostats are not going to change that, that would require physically changing the pipework.

 

[oldbutnotdead]

You could do with experimenting properly.
If rads have TRVs on set them to max, if not then just open the valves to full.
Check that all lockshields are actually open (one by one turn lockshield fully clockwise COUNTING THE TURNS NEEDED TO FULLY CLOSE, note that number somewhere then turn lockshield valve anticlockwise that same number of turns). If any were fully closed, open them by 2 turns.
Bleed all radiators (may have to repressurise after this)
Set downstairs ON, upstairs OFF.
Check boiler is running, see which rads get hot and which don't.
Repeat with upstairs on, downstairs off.
If control is merely inverted (so downstairs is operating all bedroom rads, upstairs operating all downstairs and bathrooms) then it's almost certainly easy wiring fix.
If rads are random then it gets more complex. Quite likely there are 2 manifolds somewhere central, if there are then probably not a complex fix but it's builders problem anyway.

 

[Madrab]

Thanks for your replies. It is certainly not working as it should. I'm wating for the site manager to get back to me.

I would have thought that if, for example, the downstairs control was opening the valve for upstairs, the water would flow to all the upstairs radiators not just one.

Yes, you are correct. As suggested, wiring wouldn't be an issue here. Usually the downstairs stat would control all the downstairs rads and the upstairs stat would control the upstairs rads - sometime the upstairs rad is on the downstairs zone as they can interact.

If using one stat it is meant to turn on both the bedroom and en-suite rad and it only turns on one and the other rad is turned on by the stat downstairs then it can't be piped to the correct zone.

 

[Graham27]

Thank you everyone for your replies, they are very helpful. I do think it is the pipework, since as far as I understand it, the wiring just determines which zone valve opens/closes.
Anyway the site manager is now meeting me tomorrow and I hopefully I will find out what the issue is.

 

[terryplumb]

Good luck ,do let us know how you get on.

 

[Graham27]

Just to say it was the two radiators being piped to the wrong zones. The builder is now going to correct the piping.
Thanks for all your replies.