Worcester Bosch 28CDi RSF Combi

[copper-sid]

Hi All
Just moved into a house with the above combi boiler fitted around 2002. It works great and has a built in programmer in the control panel which works the heating and hot water.
However there is no room thermostat and the missus is complaining about being unable to control heating in the conventional way..ie turning a knob!
I would like to know if I can wire in a thermostat and what type please?
I don't need a wireless stat as I can hard wire from bolier to stat location quite easily.
There is a manual for the boiler which shows where the stat should fit on the boiler.
There are 4 terminals marked NS LS LR and a spare.
The built in programmer is plugged into a circuit board. It has the normal time/day/on/off/once/twice settings which work fine. It also has a section marked " Room Thermostat " and above this are three buttons marked ON LEARN SIGNAL
At the moment the boiler will only work when the ON button is pressed. I don't know what the LEARN means and presumably the SIGNAL button means a signal from the thermostat?

Sorry for the long post but I hope this paints a good picture. I can also post pictures of the programmer and the terminals if required.

So in summary I would be grateful to know
1. Can I hard wire a stat?
2. Which type will work? (don't need wireless)
3. Do I leave the programmer alone?

Many many thanks.
Sid

 

[ChrisR]

1 yes. Option is a programmable stat so all the CH timing is done on the stat, & you can have different temps at different times of the day. Current timer going to ON 24/7, is one way to deal with that.

If you use a battery operated stat and its volt free contacts (ie nothing on the mains), you'd connect to LS and LR. (= supply and return)
(Either way round)
Batteries last several years in those. Ones which glow at you when you touch them are nice. Honeywell are great but not the cheapest.

If you (MUST! ) use a mechanical stat you'll need neutral (NS) as well, and also the orientation of S and R becoes important. That means 3 core + earth cable cos you shouldn't re-appropriate Earth for anything else.

 

[copper-sid]

Hi ChrisR
Thanks for your thoughts.
I thought I might avoid the cost of a programmable stat as the current one works fine!
Does a battery operated stat mean that there is a receiver unit wired to the boiler and the sender is elsewhere working on batteries?
If I went for the mechanical stat, which type would work? And will the existing programmer still work as normal?
Cheers.
Sid

 

[45yearsagasman]

If you want a simple hard wired stat then fit a Honeywell dt90e, and connect as suggested LS LR. Simple stat to use and around £30-35

 

[copper-sid]

Thanks for that Gasman.
I feel like i'm heading closer to the final resolution here!!
If everyone can see the pictures. My boiler has a programmer built in to the fascia pic1. You will just see that it has a Room Stat section with buttons ON and SIGNAL and in between them the word LEARN.
At the moment the boiler will only work if the ON button is pressed. It won't work if it's on SIGNAL as there is no room stat to give a signal...I think!
What I would like to know is can I wire in a simple mechanical thermostat into the terminals NS LS and LR? (pic 2) And would this work with the button marked SIGNAL? Or do I disconnect the programmer which I don't want to?
Sorry about my confusion but I thought I'd get it right.

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• copper-sid
• 27 Jul 2012
• 1

Untitled

• copper-sid
• 27 Jul 2012
• 1

 

[45yearsagasman]

That is a wireless system and as such you should have a room thermostat as part of the set up. Have you not got the wireless room stat?

 

[copper-sid]

Hi All
Gasman....thanks for identifying this as a wireless system. Unfortunately there was no wireless room stat when i moved in!!
So please tell me what I can do here?
Either find a the wireless part or can I wire in a mechanical room stat which will work with the programmer?
Cheers.
Sid

 

[45yearsagasman]

If you cannot locate the wireless room stat, then Worcester may be able to supply one as a spare together with the instructions on how to pair it up with the receiver.

 

[copper-sid]

Ok
Great. Thanks to all for the advice. i shall now try and achieve the impossible by trying Worcester!!
Sid

 

[ollski]

Standard drayton digistat transmitter should work fine with this if the receiver is still working.

 

[Agile]

You say "just moved in" !

have you bought the house or are a tenant?

If bought the seller should have left the room stat unit.

If renting, the landlord should provide a new one if previous stole it.

Tony

 

[copper-sid]

Hi
Agile...i've bought the house and the last owner said he hadn't bothered with a thermostat....somehow i now think it was a little porky!!
Ollski...thanks for your suggestion. The receiver part seems to be working so can you please give me the model number for the Drayton you've mentioned?
Or can I just wire in a simple mechanical thermostat which will work with the programmer bit?
Sid

 

[copper-sid]

Hi All
I've managed to get a little further with my query.
Worcester Bosch have identified my built in programmer and wireless receiver as part numbers 8716 156 1170 and 8716 156 1170 respectively. I'm told that I need a transmitter unit part no. 8716 156 1180 which is described as a British Gas RCH Wireless Room Thermostat.
So does anyone know if I can still get this or any equivelant transmitter please?
(I can't seem to post the picture of this unit but can message it if required)