Heating System Modification

7 Mar 2005
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United Kingdom
My central heating has 2 zones, one upstairs ans one downstairs. The thermostat for the upstairs is in the hall and the thermostat for the downstairs is in the lounge.

The problem is that when the lounge is occupied (especially when the gas fire is on), the downstairs tends to get cold.

I would like to use the thermostat in the hall (upstairs zone) to control both zones. I understandthat the radiators in the lounge would be better off with TRVs fitted (nexy job). In other words to go back to a standard system.

Can I just link together the wires in the airing cupboard junction box so that the control to the upstairs zone valve is linked to the downstairs control valve?

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Can't see anything against this, especially if you're going to put in TRVs as well.
When you do, make sure rad(s) which affect the hall stat's area are either not TRV'd or set to max, otherwise the system will never switch off!
Thanks for that. Currently the hall rad does not have a TRV as it's near the thermostat running the upstairs. Also the two rads in th elounge do not have TRVs either but I will probably put them on to control the temp.
By the way, is it just a matter of moving the control wire that goes to the upstairs zone and screwing it on the same terminal as the downstairs zone wire - in the airing cupboard junction box.

Presumably there thermostat switch can run both as they are relatively low current valve motors.
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Yes do it all inthe junction box, just take the brown wire from the downstairs zone valve out from the connection with the downstairs roomstat and join it with the brown wire from the upstairs zone valves keeping the switched phase from the upstairs roomstat.

For safety's sake in the junction box remove and terminate the switched phase (from the program controller) and neutral to the downstairs roomstat. Leave the wires safely terminated in the box should you wish in future to change back.

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