DP Programmable thermostat

Can I be rude and ask why? I could have done with something similar recently but ended up fitting a relay instead. Saved me changing to a mid position valve with all the complex wiring that involves though. Yeah, perhaps the radiators do go a bit cooler after a bath, but it's only 20 or 30 minutes...

Hwyl!

M.

I'm going to run two fan convectors off a single 2 port valve. I want the valve to operate when either programmable room thermostat calls for heat, but control each fan convector separately. As far as I am aware, the fan convectors do not have any auxilliary switch terminals for when they activate. However, I'll be happy to be told otherwise (Myson Kickspace 800).

I need the zone valve, as the primary circuit for HWC only is about a 2 metre round trip. Having the fan convector loop open would increase the primary circuit to around 40m, even in summer, much of which (i.e. the bits I haven't done) is uninsulated. (No, I'm not ripping up all my lovely floorboards to lag them!)

Christian.

The Myson has an integrated pipe stat. It only operates the fan when the heating coil is up to temperature.

To have two Kickspace each controlled by a programmer/stat and one 2-port valve, will require the odd relay or two to work right. As relays are not that cheap you may as well make is very easy and fit two 2-port valves, one for each Kickspace. BES sell them for £21 + VAT.

The problem is that it is very easy to get a single zone valve in. When I installed the upstairs/downstairs zone valves, I actually put the plumbing in for an additional one. I suppose I should have thought more about it and put in two extras. Putting two in would look less neat. It isn't really necessary to have two valves, either. It is unlikely that one room would need heat and not the other, and the heat rating of the convector with the fan off is very unlikely to be greater than the heat loss of the room.

The other alternative is to run the kitchen convector off the downstairs circuit and just have a room stat to run the fan. I could live with the kitchen off the same timing as the downstairs. It is only the conservatory where I anticipate the need for radically different timing.

Christian.

The problem with not having a zone valve on a Kickspace is that the cupboard above the Kickspace gets hot. The fan may be off, but the system is still pumping hot water around. It looks like you will need a relay. One will do.

Stat 2 energises relay. contact switch energises KSP 2 One contact switch has the Zone valve on the pole terminal The N/C terminal from this switch is fed from stat 1, which also energises KSP 1 Other terminal of switch contact is fed from stat 2

Simple.

Thinking about it, I don't really want to pump through the conservatory heater when it is turned off. This will be much of the time during winter, as I anticipate heating only 1-2 hours a day, whilst the kitchen will be on a lot. Maybe, I'll just run an unzoned 22mm past the kitchen into the conservatory and install 2 port valves locally to the heaters. There'll be plenty of space under the kitchen units for the valves, I suppose, if I position the pipework so the valves are near the plinth for servicing.

Christian.