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Help me understanding my heating installation and replacement

Hi all,

I just joined the forum as I couldn't find help just being a lurker. :)

I just bought my first house (yay me) and it's a new one. The installation has been done my a bunch of different people and the plumber himself couldn't explain fully what he's done (yes, you read it right). I tried to understand myself, open junction boxes etc but, you will see in the picture, it's a mess.

The house is configured this way (three different valves on the boiler):
  • Underfloor wet heating split into two zones for the ground floor
  • Radiators on the floors (1st and 2nd floor, 4 rooms in total)
  • Water cylinder
The underfloor heating is controlled via remote two heatmiser thermostats connected to a UH8-RF.
The radiators are all controlled via a single honeywell remote thermostat.
Then there is a Dangoss programmer in the mix (Electronic 3-Channel FP735Si).

See the attached pictures for a better idea of the installation.

My questions to the forum:
  • what is the point of the Dangoss programmer in all of that? Is it to allow each unit (UH, rads and cylinder) to turn have the boiler on? Is it really necessary?
  • I want to have smarter thermostats with something more centralised. I got three Nest Thermostat thinking it would be doable to swap all to it but the more I dig the more it looks complicated if doable at all. What do you think? I installed a Nest myself in my previous flat on a combi boiler but it was a much more straight forward installation.
I am not a good DYI person but I am not afraid of putting my hands in wires so long I know where I am going. Can you help me getting to that point please? :)

Cheers
 

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I'm curious what is the orange piping?
Heatmiser are the market leaders in smart thermostats there neostats will do everything and more than nest and hive.
 

king of pipes

Esteemed
Plumber
Gas Engineer
On the surface it doesn't look that bad the installer wasnt a complete novice where these systems fall down is when they are are wired trying to configure different makes of control can sometimes be difficult theres alot going on there a good sparks should be able to test out the separate circuits controls and explain better than your engineer or maybe with him there also I have my own electrician who I work closely with we both check systems out. Kop
 

ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
I'm curious what is the orange piping?
Heatmiser are the market leaders in smart thermostats there neostats will do everything and more than nest and hive.
Sprinkler / mister system
[automerge]1575448057[/automerge]
Looks good install but where’s your main stop tap gone it’s in the pic with the pipping but not with the final boxing ?

Also your filling loop has gone aswell ?
 
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Thanks all! My comments below.

I'm curious what is the orange piping?
Heatmiser are the market leaders in smart thermostats there neostats will do everything and more than nest and hive.
Indeed, orange pipe is for sprinklers.

Can neostats / Heatmiser automatically learn and adapt to our pattern? Can it detect if I am getting home early and turn on the heating? Those are the types of things I liked from the Nest as well the very looking style it has (thermostats are often very ugly).

On the surface it doesn't look that bad the installer wasnt a complete novice where these systems fall down is when they are are wired trying to configure different makes of control can sometimes be difficult theres alot going on there a good sparks should be able to test out the separate circuits controls and explain better than your engineer or maybe with him there also I have my own electrician who I work closely with we both check systems out. Kop
That's a good sumup ; it "looks" good indeed but behind the scene it's hard for anyone to maintain. I will have to get someone in anyway to help understanding it / cleaning and switching to something "smarter".

Sprinkler / mister system
[automerge]1575448057[/automerge]
Looks good install but where’s your main stop tap gone it’s in the pic with the pipping but not with the final boxing ?

Also your filling loop has gone aswell ?
Those are two very questions... I feel like they just buried the whole thing and I can't even fill-in at the moment (I have air in the radiators but I am afraid of venting it as I will lose pressure I can put back).
 
Hi guys,

Thanks so far for the ones who responded to my thread.

I am now really going for a full replacement of the current controls with Nest Thermostat ones. I think this is how the installation would look like:
  • I get rid of the the Dangoss programmer (it will be replaced with the Nests)
  • Hot water and radiators valves connected onto one Nest
  • UH8 zone 1 connected to one Nest
  • UH8 zone 2 connected to one Nest
Does that make sense?

Thanks
[automerge]1576247823[/automerge]
EDIT: actually the UH8-RF can't be used with anything else to control it. So I need a new underfloor heating wiring center. I will go for the UH4, I don't need 8, without the "RF" feature. Does that make sense to you?
 
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ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
What’s the two sets of brown and blue wires

Unless there paired up as 2 zones per circuit ?
 
What’s the two sets of brown and blue wires

Unless there paired up as 2 zones per circuit ?
Yes indeed, the wiring diagram shows them as 2 N + 2 L. And looking at the manifold picture I can see 4 valves so it's likely split into 2 x 2 zones actually.
 

ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
Yes indeed, the wiring diagram shows them as 2 N + 2 L. And looking at the manifold picture I can see 4 valves so it's likely split into 2 x 2 zones actually.
Need the non wireless version then sorry
 
Hi all,

I am slowly progressing in the planning of switching off my heatmiser thermostats for the Nest ones.

I am currently planning on swapping my UH8-RF for a UH4 in order to control the manifold actuator valves through the Nest. Here is the UH8-RF diagram:
Screenshot from 2020-01-03 08-24-53.png

And here is the UH4:
Screenshot from 2020-01-03 08-26-20.png

The main "problematic" difference I note is the split between the UFH pump and the UFH Valve. On the UH8 it's on two separate sockets whereas the UH4 is on a single one. Will this be a problem?

This is a reminder of how my UH8 is currently wired:
20191203_201446 (1).jpg
As you can see I only have the "live" plugged on the UFH Valve ; is it "normal"?

I think in terms of wiring I can do:
- putting everything on the UH4, ie UFH vales + radiator valve + hot water valve, so I end up with a single device plugged on the boiler. Then I would have 1 Nest controlling UF zone 1, 1 Nest controlling UF zone 2, 1 Nest controlling zone 4 (configured as radiators) + hot water.

Does that make sense?

Thanks
 
From what I can see on the new board the pump live is activated through end switch on zone valve and there must be a link to bring the boiler on that I cant see in diagram. If you follow the wiring diagram you should be ok
 
UH8RF controls the pump differently to a UH4 ( the former has an adjustable delay setting).

The current wiring for your UFH looks incomplete for the valve.

You really need an “as built” wiring diagram for your existing system - to properly understand how it is configured.
 

ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
Looks fine to me just wire it as instructions probably picking up a neutral from somewhere by the valve
 
Thanks all ; much appreciated.

I guess that the wiring on the valves is generally "safe"? ie so long I don't plug 220 on those I should be safe to make a mistake? I think I need a multimeter!
 

ShaunCorbs

Staff member
S. Mod
Plumber
Gas Engineer
Yes just follow your existing zones eg two into one

turn the power off before any works check that it is off with a multi meter
 

RoryD

Plumber
Gas Engineer
Hi guys,

Thanks so far for the ones who responded to my thread.

I am now really going for a full replacement of the current controls with Nest Thermostat ones. I think this is how the installation would look like:
  • I get rid of the the Dangoss programmer (it will be replaced with the Nests)
  • Hot water and radiators valves connected onto one Nest
  • UH8 zone 1 connected to one Nest
  • UH8 zone 2 connected to one Nest
Does that make sense?

Thanks
[automerge]1576247823[/automerge]
EDIT: actually the UH8-RF can't be used with anything else to control it. So I need a new underfloor heating wiring center. I will go for the UH4, I don't need 8, without the "RF" feature. Does that make sense to you?
If that is Nu-Heat UFH it will not operate correctly with a NEST as I was informed by Technical. Nu-Heat supply a similar unit that functions the same. also.....my concern is......why are you called Tee bag?? ........?
 
If that is Nu-Heat UFH it will not operate correctly with a NEST as I was informed by Technical. Nu-Heat supply a similar unit that functions the same. also...my concern is....why are you called Tee bag?? .?
Which "unit" do you mean? The wiring center? On paper the UH8-RF is doing the same as UH4 but with the wireless part.

Re the nickname it's a long story. :D
 

RoryD

Plumber
Gas Engineer
Which "unit" do you mean? The wiring center? On paper the UH8-RF is doing the same as UH4 but with the wireless part.

Re the nickname it's a long story. :D
The Underfloor Heating is not responsive to temperature settings remotely unless Nu Heats isused(I just believed and used theirs which worked great). Judging by your pic your Nickname came from when you served?
 
The Underfloor Heating is not responsive to temperature settings remotely unless Nu Heats isused(I just believed and used theirs which worked great). Judging by your pic your Nickname came from when you served?
Hm I am not familiar with Nu Heats ; is it a specific brand for the manifold? Can you tell it from the very picture of the OP? ("20191120_161226.jpg").

Nickname is from silly jokes at Uni and image is from gaming ; sorry I didn't serve. ;)
 

RoryD

Plumber
Gas Engineer
Hm I am not familiar with Nu Heats ; is it a specific brand for the manifold? Can you tell it from the very picture of the OP? ("20191120_161226.jpg").

Nickname is from silly jokes at Uni and image is from gaming ; sorry I didn't serve. ;)
Actually you are right it isn't Nu-Heat. However try to identify the Manufacterer and find out if it is possible. Regarding the "Spaghetti"... That is par for the course in most cases. Sometimes if there is an issue, it's best to call someone in.
 
Rory,

The units are Heatmisers - albeit they may be badged under a different brand name. My understanding is that Teabag wants to use Nest so he /she is removing the 12v UFH 8 RF unit and the Neo Air stats and replacing it with the 240v UFH 4 unit coupled to Nest. I assume he is doing this because Neo Air which is compatible with the UFH 8 RF don’t include smart TRV’s in their range to control the radiator circuits (you have to use air stats and zone valves) An alternative would be Evohome to control everything - but that is In a different price league.

It is a fairly straightforward change, provided you wire the UFH 4 (240v) correctly and don’t just copy the 12v UFH 8 RF wiring.
 
Rory,

The units are Heatmisers - albeit they may be badged under a different brand name. My understanding is that Teabag wants to use Nest so he /she is removing the 12v UFH 8 RF unit and the Neo Air stats and replacing it with the 240v UFH 4 unit coupled to Nest. I assume he is doing this because Neo Air which is compatible with the UFH 8 RF don’t include smart TRV’s in their range to control the radiator circuits (you have to use air stats and zone valves) An alternative would be Evohome to control everything - but that is In a different price league.

It is a fairly straightforward change, provided you wire the UFH 4 (240v) correctly and don’t just copy the 12v UFH 8 RF wiring.
Hi Rory,

It's a pretty good sum up. :)

I am confused by the 12v vs 240v part though, the wiring diagrams are both showing they are operating 240v actuators?

Thanks
 
Teabag

The inputs to a Heatmiser UFH8 are 12v through Neostats - in the RF version you dont see it, but the actuators et al are switched at 12v with a 240v output.

For Nest, I assume you are switching at 240v with 240v outputs, hence using the Heatmiser UFH4?

My comment on not copying the UFH8 wiring across to the UFH4, but to work to the wiring diagram and “bell” the existing wires is good practice to avoid mistakes.

From your photos one of the valves is only taking a positive feed from the UFH8 - I assume that it works and that the installer was short of a core to bring neutral back to the UFH8 - that is not good practice. So, if it was me, I would check out all the wiring.

There is nothing wrong with what you are proposing with Nest and with the UFH4 it will work - apologies if I confused you.
 
Teabag

The inputs to a Heatmiser UFH8 are 12v through Neostats - in the RF version you dont see it, but the actuators et al are switched at 12v with a 240v output.

For Nest, I assume you are switching at 240v with 240v outputs, hence using the Heatmiser UFH4?

My comment on not copying the UFH8 wiring across to the UFH4, but to work to the wiring diagram and “bell” the existing wires is good practice to avoid mistakes.

From your photos one of the valves is only taking a positive feed from the UFH8 - I assume that it works and that the installer was short of a core to bring neutral back to the UFH8 - that is not good practice. So, if it was me, I would check out all the wiring.

There is nothing wrong with what you are proposing with Nest and with the UFH4 it will work - apologies if I confused you.
Thanks mate, appreciated your feedback.

I think you are showing that I neglected the difference in tensions between the Next and UFH4 / 8. The UFH4 is expecting 12V to from Neostats and the Nest would send 240v. I was thinking of indeed replacing the Neostats from the UFH4 diagrams by the Nest wires directly. Am I good to send back the UFH4?...

EDIT: the below diagram shows it's actually expecting 240v thermostat, so I should be able to plug the Nest Links directly?
Screenshot_20200107-101054_Drive.jpg
 
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UFH4 is 240v signal - fine for Nest. UFH8 and UFH8 RF (albeit this in hidden in the RF version) is 12v signal.
So to clarify for my own piece of mind the UFH4 switches 230 from stat to actuators but UFH8 and RF switches 12 to and from stat and to actuators?
 
So to clarify for my own piece of mind the UFH4 switches 230 from stat to actuators but UFH8 and RF switches 12 to and from stat and to actuators?
If I got it right all the way the UFH8 is switching at 12V on the board but activate the actuators using 240V. It must have been simpler to use 12V as it's done remotely / internally.
 
SJB - despite the similarity in names the controls are very different in the way you can integrate them into a control system.

UFH4 is a simple controller that can be easily adapted to utilise different actuators and thermostat inputs for UFH and a zoned radiator group.

UFH8, is direct wired, with a wider control capability. 1 to 7 of the zones can be used for UFH or a radiator zone through software settings at the thermostat. Zone 8 can only be used as a radiator zone. It is designed for use with Neo Stat and is not user friendly to integrate with other manufacturers stats / timers.

UFH8 - RF is as UFH8 but is only suitable for use with Neo Air stats / timers - unless you are a Geek on understanding protocols.

The issue, as I see it, with the Heatmiser range is that they are excellent for UFH - possibly best in class, but when you want to combine a number of radiator zones in conjunction with UFH zones, the user interface becomes overly complex. Their product range / capability for the control of radiator zones is a long way from best in class.

Teabags preference to convert to a single wifi / app enabled system that the user can understand is a common request.
 
Hi folks,

I just want to update my own thread after 6 months+. I actually did all the work discussed above back in March and got enough time to conclude everything has been working as expected since I changed my system for a Nest controlled one.

When I did in March it was still a solid winter so it gave me the confidence the heating was still working as good as my previous thermostat with all the convenience of the Nest system.

I am attaching a picture of the final wiring with the three Nests on the UH4. I am sure there is room for improvement, on the actual cable management but also on some wiring themselves (like the HW valve only wired on the L on the UH4). Second picture is how it looks once all boxes are closed.

I didn't put any picture of the wiring for each thermostat but it was reasonably simple. I used an LED transformer for each of them in order to get 12V next to my 220V sockets. Last picture attached is the one of a working thermostat!

Anyhow I hope this can help someone else looking for a similar setup. :)
 

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