What am I missing? Heating controls

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Savage87

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Hi, I have a combi boiler which has 2 motorised 2 port valves, 1 going to upstairs radiators and 1 going to ground floor underfloor heating.

Before installing the underfloor heating I had a wireless room thermostat which controlled the heating. Heating on -> boiler on. (This has it's own wireless receiver)

Now I have a wiring centre for the underfloor heating which has 8 zones Heatmiser UH1-W but only using one for the UFH and in parallel I'm using the old wireless thermostat for the rads.

I've just bought another wireless thermostat that works with the wiring centre UH1-W programmed it to work on one of the zones, it does turn on/off the motorised valve on and the actuator(230v) that goes to one of the radiators but if the desired temperature is reached and the old thermostat which is not linked to the UH1-W is still calling for heat the actuator doesn't shut down as it's still energised because the motorised valve for the rads is still on.

I'm trying to find a solution so the actuator shuts down when the thermostat reaches the desired temperature if another actuator/thermostat/motorised valve is still running.

I hope it all makes sense. Any help would be appreciated. Thanks!

Alex N

 
Rip it all out, start again logically.

Downstairs, the ONLY thermostat(s) should go the the UFH wiring centre.  When ANY UFH zone calls for heat, the UFH wiring centre has a call for heat output which should open it's motorised valve (it's own wiring will turn on it's circulating pump)

Upstairs you might want a conventional room stat and that will turn on the motorised valve for the radiators.

And the final part of the jigsaw is the feedback contacts from both motorised valves are connected in oparallel and call for heat from the boiler when either is opened (and turn on the boilers circulating pump)
 

 
If you take the time o look inside the heat miser unit you will see that you can intact wire your conventional heating (rads) system into the heat miser unit.  This is controlled separately to the ufh aspect by the unit. 

 
Thanks for your reply guys. Dave, I've started it logically and I'm not going to rip it out :). It did the job that I wanted it to up until I got another wirelless themostat for the UFH wiring centre.

Where I'm a bit stuck is that I need some sort of device or something that can sit in between the contacts of the zone that controls the rads and the motorised valve so when the temperature is reached in one of the rooms it will close the actuator which is installed on the radiator valve(where the TRV use to be).

I only have one motorised valve for 4 room/rads. I want to get a wireless thermostat that connects to the wiring centre for each room.

Example:

Room 1: Wireless room thermostat calls for heat -> actuator on rad1 switches on -> motorised valve switches on -> boiler goes on.

Room 2: Wireless room thermostat calls for heat -> actuator on rad2 switches on

If room1 has reached temperature stat will send signal to wiring centre to switch off the actuator. This doesn't actually happens because stat2 is still calling for heat and motorisez valve is still on which is connected to the same L and N of the zones. How can I acheive what I'm trying to do?

I will post a couple of links of the kit that I have.

UH1-W diagram: https://www.heatmiser.com/en/download/79/wiring-centres/4426/uh1-w.pdf

PRT-UWTS: https://docs.google.com/viewerng/viewer?url=https://www.heatmiser.com/en/wp-admin/admin-ajax.php?juwpfisadmin%3Dfalse%26action%3Dwpfd%26task%3Dfile.download%26wpfd_category_id%3D76%26wpfd_file_id%3D4423%26token%3D1d754a0c63742f76462e908ff8ff63e5%26preview%3D1

2 core 230v actuator: http://underfloorparts.co.uk/product/thermal-actuator-ufch-polypipe-polyplumb-pb00401/?gclid=Cj0KEQiA6_TBBRDInaPjhcelt5oBEiQApPeTF-2_K39KuH846usKlpyR_XCxtnuw4k9Clj-7QykexUQaAm1j8P8HAQ

Once again, any help would be appreciated!

 
Okay, the under floor bit downstairs is irrelevant. concentrate on upstairs.

You need to replicate what the UFH controller does, which is actuate the motorised valve for upstairs when ANY of the upstairs room stats calls for heat.

Are you saying you have fitted those actuators to a conventional radiator? if so how?

Even if they fit, they might open the radiator valve, but won't give any feedback contact to turn on the motorised valve for the radiators.

If you have managed to get those actuators to physically operate a radiator valve, then the simplest solution is another "under floor" controller upstairs.  It won't know or care  that it's actually controlling radiators and will provide all the logic needed.

 

 
Last edited by a moderator:
The actuators should fit normal rad valves as they generally come with a threaded ring which screws on where the valve head usually goes and has a push fit ring that receives the actuator head. 

You could wire a separate controller for the upstairs rads and use the wireless stat for rads? 

Alternatively you could wire the rad actuators back to the original controller and use a second zone for upstairs, however if you want individual radiator control then you'll need a separate stat for each rad/zone. 

 
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Yes but if you want to control each room individually then each room needs a thermostat (wired or wireless is irrelevant) and each rad needs an actuator, all connected to a controller.  By far the simplest would be a completely separate controller for upstairs. You can't do it with just one connection to the downstairs UFH controller.

And thanks to Sharpend, I never knew you could fit those actuators to conventional radiators.
 

 
The wireless thermostats have a setting on them that you can choise if it controls ufh or rads, so when it's set to rads it will only liven up the zone that it's set to and not the manifold valve and pump.

Yes, you can screw on the actuators on the radiator valve, the only downside is that it takes about 4 minutes to fully open.

Dave, I can do that with the one controller, I will be buying more room stats for the UH1-W, but first I need to figure out how to sort out this problem.

 
Zone 1 must be for ufh, then alternate zones are optional rad zones, thus connections for valve! Look at the diagrams! 

Have to say this seems a totally inefficient method of controlling rads? 

 
What would you suggest Sharpend ?

That diagram above is what's come of the manufacturer's website.

Like I said above you can programe the stat to do either ufh or rads.

What I've done I've connected L and N from zone 2 going to 1 rad and also connected blue and brown from motorised valve to the same ports of zone 2.

If I'm going to connect another actuator to zone 3 and the same motorised valve, when one is enegised it will keep both rads/actuators on until both have reached temp. Does it make sense?

 
I don't think you can.

What they are showing is one individual motorised valve for each radiator.  That would work, but it a totally over the top plumbing solution.

What you want is one "master" motorised valve to open when ANY radiator calls for heat. I can't see you can achieve that with what I am seeing. you CAN achieve that with a separate controller for upstairs and making it THINK it's controlling UFH. That's the solution I think you need.
 

 
The uh8-rf is the newer version of the UH1-W, it does the same job

I don't think you can.

What they are showing is one individual motorised valve for each radiator.  That would work, but it a totally over the top plumbing solution.

What you want is one "master" motorised valve to open when ANY radiator calls for heat. I can't see you can achieve that with what I am seeing. you CAN achieve that with a separate controller for upstairs and making it THINK it's controlling UFH. That's the solution I think you need.
 
I understand what you're saying as you can connect the valve for the rads where the manifold valve is supposed to connect. That would work, but I'm trying to see if that can be avoided. Thanks!

 
I think you are misunderstanding the drawings. 

The zone 2 is where the rad valve is connected. Zone 3 is where the actuator is connected. Now on each actuator zone a max of 3 actuators can be connected. Therefore one valve can work 3 rads or three valves are connected if plumbed as valve per rad? 

 
Sharpend, that diagram is the standard diagram, you are not restricted on which zones you can use for ufh or rads. You can have 1 ufh zone and 7 rad zones or 7ufh zone and 1 rad zone..

The actual diagram that I have installed is zone 1 -> 3 actuators for ufh, zone 2 -> 1 actuator on 1 rad that activates the motorised valve when active.

and I'm planning to use zone 3,4 and 5 for another 3 rads which will have 3 actuators on them that will all activate the same motorised valve as zone 2. Is it clear? :)

 
So how do you propose to use the same valve? 

You need one valve and one actuator per rad, the controller will not differentiate the valve between each actuator. 

 
The way you have connected the actuator and valve will open the valve and actuator together for that rad as the controller will only send one signal to that zone port despite what is connected to it. 

 
I now have it wired like that, but it doesn't fully work as I want it, hence this thread..so, what am I missing?

In my mind I need "something" in between the connectors of the zones and motorised valve, some sort of switch/relay, I don't know?!

 
The way you have connected the actuator and valve will open the valve and actuator together for that rad as the controller will only send one signal to that zone port despite what is connected to it. 
Correct, but how can I stop heating one room when the others are still heating? How can I make one of the actuators shutdown whilst the motorised valve is still running?

 
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