I am considering overhauling and zoning my central heating later this year, and would like separate control of each rad. I'm looking for motorised valves which are as small as possible and which will fit on 15mm pipes. The only ones I can find are 22mm. [Yes, I know I can use reducers - but the whole thing is still too big].
Does anyone know whether smaller ones are available and, if so, where from?
TIA.
I assume they will be visible.
I am planning to do something similar, linking it all into a home automation system. I was planning to use solenoid valves, as (like you) I have discounted motorised valves as too big / unwieldy.
I'll probably buy mine from Asco
The only concern I have is the 'clunk' as they switch, but hopefully an anti water hammer model will avoid that.
HTH,
Chris
I have seen ones in Scandanavia that appear to use the valve from a TRV together with what I assume is an electromagnet. This is 15mm and very small, though the peak flow is quite low I imagine.
But not sure where you get them in the UK.
In article , G&M writes
The ones I've heard of use the mechanics of a TRV and a heater to activate the TRV capsule. Have seen them recently in individual hospital rooms to have timed control but they seem to be v expensive by virtue of low demand. They have been mentioned in this group, try a google groups. Andy Gabriel I think has mentioned making a low cost version by adding a heater to a regular TRV, again google.
Set Square wrote on Sunday (22/02/2004) :
Solenoid valve are available which are quite small, the problem might be the noise they make as they energise and de-energise. They are though much more reliable than motorised valves.
A good solution for this is to use Sauter drives in place of the TRVs.
The cheapest is the AXT111 F200 which is a thermal drive. These fit onto the base of a TRV in place of the normal head
RS have these at about £35, but a better deal should be possible from Controls Center.
You could also fit one of these drives onto a 15mm base which Sauter also makes.
I've used some of Sauter's motorised drives (AXM 117S)
It should be possible to control a thermal drive with either a simple thermostat or a pulse proportional controller like a CM67 or equivalent.
.andy
To email, substitute .nospam with .gl
Sounds interesting, and could be better than trying to hide motorised valves under floorboards etc. I note from the pdf file that they also have optional auxiliary contacts - which should make it possible to integrate them into an S-Plan-plus control system. The only thing is, though, that the contacts make when the valve is 35%-50% open rather than fully open. I'm not sure whether this is a problem? I suppose if the boiler and pump fire up a bit early, it's not too disastrous as long as there is an automatic by-pass circuit. I suppose, also, that it's far better than the alternative of having a relay in parallel with the valve - which switches when the "start to think about opening" command is sent to the valve!
I don't think that that would be a problem at all.
Think about the behaviour of simple TRVs. These have a thermal capsule which expands and pushes down the pin of the valve. This is an "analogue" effect, not a "digital" one, so at different room temperatures the valve would be anywhere from fully open to fully closed.
If you are concerned about the bypass aspect, you could always fit a pressure activated automatic bypass valve.
.andy
To email, substitute .nospam with .gl
motorised
Search for "prefect controls". I have posted about my experience with these heads for trv bases a couple of times, and I'm still pleased with the results. I have three of these waiting for a suitably shaped tuit.
In article , John Stumbles writes
in '99 ;-). I've eight zone valves in my control cupboard, with sep pipes to each zone (room). Pipe runs were easy for me so I went that route. Retrofit or difficult runs & I'd be going the resistor route, needs the right TRV tho'; the cheapies I got from s'fix would have been a b'ger to modify, Draytons strike me as an easy option with the big exposed head .
The obvious way would be to use a couple of reducing 22/15 sets in place of the
22mm olive in a 'standard' control.
We seem to have gone full circle! In my original post - quoted in full above - I said, "Yes, I know I can use reducers - but the whole thing is still too big"!
honeywell have just produced a valve that replaces the rad valve and can be set up for various tempratures in each room which is cordless and will send a signal to the boiler to fire when a rad requires it. probably costs a fortune !
If you are referring to the HR80, I phoned RKM Heating Controls for pricing, as suggested by Set Square, but they have not had any details from Honeywell yet. Also, the CM67z is a 2-zone affair and from a previous thread it seems Set Square wants more control than that.
Regards
Neil
Yes, that's right! It currently looking like a CM67 (not z) in each room, with one of those wax-heating valves on each rad. I'd still really prefer a motorised valve which could be fitted in the 15mm pipework under the floorboards or inside cupboards - and which is much smaller than a normal
22mm valve plus reducers - since far less would then be visible, and there wouldn't be any cables connected to the rads. Unfortunately, I haven't found anything suitable yet!
cordless
Gap in the market?
Maybe! Or maybe the motor part would still have to be the same size - in which case there wouldn't be much saving in space by the valve itself being
15mm rather than 22mm.Unless anyone knows differently . . .?
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.