adding honeywell type valve for zone control

[news]

At work we occupy an old coach house with a 1950s ballroom attached, The heating is all on one zone and the ballroom has 3 radiators supplied under floor, the rest of the house has a mixture of pressed steel radiators with lockshield valves and old cast iron radiators with 30mm valves. The ballroom gets hot before the rest so I am considering putting a honeywell valve where the inlet pipe goes under the floor (in a boiler room adjacent to the ballroom) and using a wireless thermostat from the ballroom to cut flow just to this zone when the thermostat is satisfied. Can anyone see fault with this idea?

AJH

[harryagain]

You'll probably find it's well rusted steel pipe if it's that age.

The sort of job that could easily escalate into something major/complete renewal as the pipe might break if disturbed. Have you got the pipe screwing equipment?

If it's all one zone, how is fitting a zone valve going to turn one part of it off?

[fred]

In article , [e-mail] writes

Basically a sound idea with a couple of mild reservations:

Zone valves aren't continuously rated so it would be better if you feed the live feed to the wireless receiver relay contacts from the boiler demand. This means that the zone valve will only become energised when the rest of the house and the ballroom are calling for heat.

Whilst they are one of the most user friendly range of wireless stats, I would suggest avoiding Honeywell models for this application as they only offer proportional control. This means that they will cycle at times that cannot be guaranteed to coincide with the demand from any main house stat. Better to choose one with simple on-off control which is more common on cheaper stats and jumper selectable on a few of the more expensive ones.

[news]

OK but is there a zone valve that can be motored up or down from the thermostat without needing to be continuously fed?

Any suggestions for a cheap one?

Thanks

AJH

[fred]

They're uncommon in domestic installations (so expect them to be expensive) and outside my experience but there are a couple of makes mentioned in the group FAQ:

I'd expect you to need a stat with changeover contacts but I'd expect that to be the norm on those that you will be considering. Check in the specs that they don't mind having the excitation voltage applied continuously.

I've used the wired version of this Grasslin wireless model:

56quid so less than most and it is at least a known brand.

It's adequate if a tad less easy to program than the market leaders but the printed crib sheet on the back of the little door on the RHS that hides a couple of extra programming buttons is clear enough. No automatic GMT/BST switching.

[Tim Watts]

There are but I've never seen one in the wild.

I was not aware of a zone vale not being continuously rated - that would be a serious flaw as some places my be calling for heat for long periods in the winter.