Quick Thermostat Question

[Ste Crook]

I want to replace this honeywell thermostat with this Salus one, and I cant work out which wires are meant to go into which, any help would be greatly appreciated

On the Honeywell one I think the Live goes to number 1 (on the right) and the neutral into number 2 (second from the left)

I am pretty much just baffled with the last one?

Cheers
Ste

 

[davesparks]

Based on the information provided you need to run another cable to the thermostat from another part of the central heating control circuit where the permanent live of the system is present. This is due to there being no permanent live at the existing thermostat.

Wires at the existing thermostat are as follows:
Red - Sw live from programmer
Yellow - Sw live to valve
Blue - Neutral

 

[Ste Crook]

Cheers Dave,
It should work as it is though shouldn't it? The previous one worked ok until the heating started turning on even though the thermostat was right down.

 

[Meggerman]

You could just link L to COM but display will only be on when programmer is calling. I would buy another room stat that you can use the wires you have.

 

[Ste Crook]

You could just link L to COM but display will only be on when programmer is calling. I would buy another room stat that you can use the wires you have.

When the programmer is calling? Sorry i'm not that well up on boilers, and the reason I bought a wireless thermostat is I don't want the thernostat in the same room as its already in as its significantly colder than any other room in the house

 

[davesparks]

Cheers Dave,
It should work as it is though shouldn't it? The previous one worked ok until the heating started turning on even though the thermostat was right down.

Does the old thermostat make a click sound when turned up and down?

Does turning the heating off at the programmer prevent this problem?

How was the faulty thermostat diagnosed?

Based on experience that mechanical thermostat is likely to be fine, my first port of call for this fault would be an issue with the valve.

 

[Meggerman]

When the programmer is calling? Sorry i'm not that well up on boilers, and the reason I bought a wireless thermostat is I don't want the thernostat in the same room as its already in as its significantly colder than any other room in the house

Sorry, I just saw the back of it and assumed it was a room stat not an RF one. In that case you need to replace it with a programmable room thermostat (will do both timings and temp) and convert your existing red wire to perm live at either wiring centre or programmer (you have not stated if S / Y Plan or combi).

 

[davesparks]

You could just link L to COM but display will only be on when programmer is calling. I would buy another room stat that you can use the wires you have.

No it won't, that's a wireless thermostat receiver he's got there, you can tell by the writing on the label and the fact its got dip-switches to set and address.

 

[Meggerman]

No it won't, that's a wireless thermostat receiver he's got there, you can tell by the writing on the label and the fact its got dip-switches to set and address.

Yeah , I realised after writing it, see my last

 

[Ste Crook]

Does the old thermostat make a click sound when turned up and down?

Yes, but usually always at the same place

Does turning the heating off at the programmer prevent this problem?
There is a timer with a Off / Twice / Once / 24Hr in another room, I tend to turn the heating off here as otherwise the thermostat has a constant red light on it (showing its active?)

How was the faulty thermostat diagnosed?
It wasnt really, I just wanted a new one, its in a hallway which has no heating so is always cold

Based on experience that mechanical thermostat is likely to be fine, my first port of call for this fault would be an issue with the valve.

 

[Ste Crook]

Also its a combi boiler

 

[davesparks]

Rules out a valve then!

 

[Meggerman]

Rules out a valve then!

He may have 2 heating zones..... but unlikely

 

[davesparks]

Ok then, bearing in mind the roomstat should be in a room without a TRV on the radiator.

Is the new roomstat programmable or just a roomstat?

If programmable you could get a suitably qualified person to connect it directly into the combi boiler and disconnect the existing controls. Do not do this yourself

If it is just a stat then it may be best mounted next to the timeswitch where all of the necessary connections should be available (or could be made available easily). The existing roomstat could then be replaced with a blank plate.

 

[davesparks]

He may have 2 heating zones..... but unlikely

Using a little bit of logic he has not said anything about the fault only affecting downstairs or upstairs heating or any mention of the heating of a specific area.
And the colour of the existing cables gives a good guide to the age of the installation, sometime before multi-zoned installations became popular.

 

[Ste Crook]

Don't think so,

Basically the combi boiler is upstairs, and downstairs I have that thermostat, then in another room I have a Drayton SM1, and a big power switch to turn it all off.

I am just baffled as to why the other day I had the Drayton Box set to 24 hours but the thermostat set right down the heating was still on

 

[Ste Crook]

The new thermostat is a Salus RT300RF, would this be compatible or do I need to go for something a little higher budget?

 

[Meggerman]

Using a little bit of logic he has not said anything about the fault only affecting downstairs or upstairs heating or any mention of the heating of a specific area.
And the colour of the existing cables gives a good guide to the age of the installation, sometime before multi-zoned installations became popular.

He did not mention it was combi either, and that is probably converted from a old Y Plan that got ripped out. Also I did plenty of multi zoned systems on the old colours. Maybe I operate in a more desirable area

 

[rdelectrical]

Get a Honeywell one far better than salus I fitted one for a customer lasted 2years Honeywell far better and easy to fit

 

[davesparks]

Ah well I started my apprenticeship right at the point of changeover, wholesalers were just selling off their last drums of old colours and starting to sell new colours.

I've never yet done a multi zoned system on a combi, done a couple with two boilers in paralell and two heating, two hot water cylinders and a towel rail zone though.

 

[davesparks]

Get a Honeywell one far better than salus I fitted one for a customer lasted 2years Honeywell far better and easy to fit

I've removed plenty of honeywells because customers find them a bit too complicated when all they want to do is just turn their heating on and off!

In my experience the average person just wants their heating to work without any fancy gadgets and such nonsense, keep that for the non essential things

 

[Ste Crook]

I have a feeling its using existing wiring from an old system, we only bought this house last year and the previous owner said they got the Combi boiler 5 years ago.

Could this be why I am having issues? Because there wasnt enough existing cables running through the walls?
I know when I was having some work done a workman took the Drayon box off the wall, and when he put it back on the heating wouldnt work at all, turned out there was this really short wire which had come out which had just made the boiler refuse to work. He seemed pretty puzzled by it because everything looked as if it should be working but it wouldnt.

Whats the best solution and how much is it likely to set me back? I know someone who is a gas fitter but I'm just not sure what it actually needs

 

[davesparks]

The new thermostat is a Salus RT300RF, would this be compatible or do I need to go for something a little higher budget?

That will be fine, if possible the receiver part of the thermostat would be easy to install next to the timeswitch (drayton SM1 unit) with a short bit of 5 core linking the two (or two twins)

 

[Ste Crook]

I've removed plenty of honeywells because customers find them a bit too complicated when all they want to do is just turn their heating on and off!

In my experience the average person just wants their heating to work without any fancy gadgets and such nonsense, keep that for the non essential things

Well said, I try and use as little gas as possible, which is why the thermostat was in a bad place, who in the right mind put a thermostat in a hallway near the front door?

 

[davesparks]

I have a feeling its using existing wiring from an old system, we only bought this house last year and the previous owner said they got the Combi boiler 5 years ago.

Could this be why I am having issues? Because there wasnt enough existing cables running through the walls?
I know when I was having some work done a workman took the Drayon box off the wall, and when he put it back on the heating wouldnt work at all, turned out there was this really short wire which had come out which had just made the boiler refuse to work. He seemed pretty puzzled by it because everything looked as if it should be working but it wouldnt.

Whats the best solution and how much is it likely to set me back? I know someone who is a gas fitter but I'm just not sure what it actually needs

That will be the link between permanent live and the common terminal of the timeswitch, any electrician should have known this, and if he wasn't an electrician he shouldn't have been messing with it!

 

[Ste Crook]

That will be fine, if possible the receiver part of the thermostat would be easy to install next to the timeswitch (drayton SM1 unit) with a short bit of 5 core linking the two (or two twins)

Fantastic, thanks for that, yes if thats got the correct contacts it shouldnt be too much hard work then.

 

[Ste Crook]

That will be the link between permanent live and the common terminal of the timeswitch, any electrician should have known this, and if he wasn't an electrician he shouldn't have been messing with it!

Hahah, I think he had just missed it because for some reason it was much shorter than the others....or wanted to get home

 

[davesparks]

Well said, I try and use as little gas as possible, which is why the thermostat was in a bad place, who in the right mind put a thermostat in a hallway near the front door?

The theory as I was taught it:
Thermostat in coldest room (not in a draught though) so that when that room has got up to temperature all others must already be up to temperature and so switches boiler off. All other rooms are controlled by the thermostatic radiator valves so that they each shut down as they reach temperature. The radiator in the room where the thermostat is should not have a thermostatic valve.

 

[davesparks]

Fantastic, thanks for that, yes if thats got the correct contacts it shouldnt be too much hard work then.

Easy job for someone who knows what they are doing, but be careful there are too many people selling themselves as electricians who will be incapable of a simple task such as this.

 

[Ste Crook]

The theory as I was taught it:
Thermostat in coldest room (not in a draught though) so that when that room has got up to temperature all others must already be up to temperature and so switches boiler off. All other rooms are controlled by the thermostatic radiator valves so that they each shut down as they reach temperature. The radiator in the room where the thermostat is should not have a thermostatic valve.

That makes sense and explains a few things, for example where the thermostat is, there is no longer a radiator in the room, we created a small additional room. Then in the living / dining room radiators don't have thermostatic valves....so basically the living room is just getting hotter and hotter as they have to valves to turn them off and the thermostat in the hallway just isnt getting any warmer.

 

[davesparks]

If it was my house, and if the hallway thermostat is on the other side of the living room wall I would drill through and move it into the living room.

But then I guess if it was my house I would move the wiring into the living room wherever it is at teh moment.

 

[Geordie Spark]

The new thermostat is a Salus RT300RF, would this be compatible or do I need to go for something a little higher budget?

It has NOTHING to do with "budget" - either high or low - but EVERYTHING to do with compatibility and that has nothing to do with price!!

You have given us no information on the boiler so how can we tell you if it's compatible??

If you're wanting this stat to be of the wireless type so you can have it in a room rather than the hallway (sensible in my view) then the place to fit the receiver (for the stat) is right next to the programmer and wire it into that. How to wire it is something we won't know without seeing it in the flesh so to speak and it is NOT a job for a person of your very limited ability.

 

[davesparks]

Hey, that's what I've said, mostly, or at least what I meant to say

 

[Geordie Spark]

Hey, that's what I've said, mostly, or at least what I meant to say

I know .. I just tarted it up for you and increased my post count a bit

If he's up to it though, the answer is a programmable wireless room stat with the receiver wired straight into the boiler and ditch the existing programmer. It would be by far the easiest option for me but that's because heating controls was one of my "things".

 

[davesparks]

Thanks!

Now you see I would have to disagree on the programmable roomstat, terrible things. I have removed many at clients requests due to them not understanding them or how they work or how to set them. And I agree with them, a simple to use programmer and a roomstat which you can turn up and down as desired.
I'd go so far as to say if rather have a sunvic tlm/tlx/tl whatever it is, good solid mechanical and most seem to still be working fine.

 

[shanky887614]

Well said, I try and use as little gas as possible, which is why the thermostat was in a bad place, who in the right mind put a thermostat in a hallway near the front door?

they did that in my house, honestly there idiots

 

[Geordie Spark]

they did that in my house, honestly there idiots

It was common practice especially in council houses and I've never fully understood why.

 

[Geordie Spark]

Thanks!

Now you see I would have to disagree on the programmable roomstat, terrible things. I have removed many at clients requests due to them not understanding them or how they work or how to set them. And I agree with them, a simple to use programmer and a roomstat which you can turn up and down as desired.
I'd go so far as to say if rather have a sunvic tlm/tlx/tl whatever it is, good solid mechanical and most seem to still be working fine.

It may come as a surprise to you, but I agree with you that programmable room stats can be a nightmare to set. I had two of them in one of my houses - one for the front half & one for the back half (don't ask!!) and it took a while to get them sussed but once I did the whole system worked like a dream.

I have one in the house I have now and it's fine and not too hard to set up but that's maybe because I served my apprenticeship on the last one!!!

 

[wozz]

Only fitted a couple of salus units and my god the customers struggled a lot with using them. They were up there with polyplumb for being non user friendly.

 

[Ste Crook]

yeah you're right, I did only provide limited information, I presumed it would be a little more straight forward than it is. I will ask an electrician to have a go at fitting it.
Unfortunately its not as simple as drilling through the wall and putting it on the other side, good suggestion though, just the theromostat is on the opposite wall.

 

[davesparks]

It is very simple for an electrician, but also very easy for someone with no experience to either end up with heating which doesn't work at all, or just wont switch off.

If it is possible to install the receiver next to the prgrammer then it should be a matter of an hours labour and a foot of cable, not a huge price to pay for a working heating system.

 

[davesparks]

It may come as a surprise to you, but I agree with you that programmable room stats can be a nightmare to set. I had two of them in one of my houses - one for the front half & one for the back half (don't ask!!) and it took a while to get them sussed but once I did the whole system worked like a dream.

I have one in the house I have now and it's fine and not too hard to set up but that's maybe because I served my apprenticeship on the last one!!!

Not surprised at all, you seem like a terribly sensible chap, great minds often think alike and of course comrades from 'the radio 3 of forums' should stick together

I guess my issue is not so much with the stats themselves as with the idiots who install them for people who don't want or understand them.
In the last week I have removed them from 2 houses, one where the poor people were still turning the heating on and off at the programmer (disconnected CH channel) and wondering why it didn't respond. Second one they had left the programmer connected, and the old roomstat on the wall but disconnected, they were setting times on the programmable stat then turning the disconnected stat up and down.

Both times I explained to them what these stats were all about and how they work and they both asked if they can have a normal stat and programmer combo, obviously I said yes and fitted what they wanted.

 

[ncpitts]

the terminal you dont know on the honeywell is the switched live.

Put honeywell no. 1 (red ) into the live of the Salus and link to com
Put honeywell no.2(blue) to N (neutral) on salus
Put honeywell no.3 (yellow) into NO (normally Open) on the salus

Then put the central heating part of your programmer onto constant if your salus is a programmable thermostat.

Hope this helps

 

[davesparks]

What a bodge!

 

[ncpitts]

What a bodge!

Why ?
The chap asked a a specific question that has been answered.
I could have gone on to say to take the cable it of terminal 4 if the programmer and make it a permanent live and also change the clock to a single channel, but that's not what he asked for.
If the only thing you cab say it's to criticise then please, say nothing.
If this is representative of the way people's input is considered then maybe it's best not to post at all .
Thought this was a place to share knowledge and experience
Rant over

 

[davesparks]

It's a bodge because you end up with no time control of the heating and a wireless stat receiver in the hallway looking ugly.

If you had read the thread properly you will see that the unit is a thermostat and that the existing time control is a timeswitch, not a programmer.

You suggest making the cable currently connected to terminal 4 of the timeswitch a permanent live and changing the timeswitch to a single channel unit (which he has already told us it is), this won't achieve anything as there will not be a wire connected to terminal 4.

I criticised because your advice is unsound and not coherent with the information the OP has given.

Yes this is a place to share knowledge, but you have not shared knowledge, just handed out inappropriate advice.