RWB2 buttons won't move

[Richyyy]

I have central heating controlled by a Landis & Gyr RWB2, looks exactly like this one:

I don't use the timer (or the little buttons to the right-hand side, really), just slide the bigger buttons all the way from 'off' to 'on' when I want hot water or the heating on. The whole thing's been constantly buzzing for a while, but continuing to work fine, so I just ignored the noise. Today, I tried to slide the bottom button over for hot water, and it just wouldn't move. It's always been a bit stiff, but it's clearly different this time, and actively preventing being moved. Took the front section off the wall, and still nothing would move (nothing obviously wrong inside, but I don't claim to have any idea what I'd be looking for).

So my basic question is what do people think is likely to be the issue? Do those buttons need power to be released to move, so it's something to do with the wiring on the wall section? Is the thing anywhere near 'smart' enough to block me from moving the button if there's something wrong elsewhere in the system? Do I just need to buy a new control panel, stick that on the wall, and it'll start working perfectly fine?

Any advice or help would be greatly appreciated.

 

[flameport]

The sliders are just mechanical switches.
If they don't move they are broken.

The solution is to buy a new programmer.
Just be sure to make a note of which wire(s) go to which terminals before removing the old one.

 

[Hugh Jaleak]

This : http://www.heatingcontrolsonline.co.uk/siemens-landis-staefa-rwb2e-programmer-p-41.html or this : http://www.heatingcontrolsonline.co.uk/siemens-landis-staefa-rwb29-programmer-p-43.html should be a straight swap onto existing backplate. Other units may require rewiring of the backplate.

Turn power OFF before removing or replacing the programmer otherwise you may blow the new unit!

 

[MANDATE]

I have the same programmer. Going back about 12 months I had a problem where the timer clock had stopped, but I could still switch the boiler on or off.
I did partially dismantle and from what I recall there was nothing complicated.
There is no power needed to operate the sliding switches and its nothing to do with the wiring.
It will be pure mechanical and whatever is preventing them from moving will be obvious when you remove the front. probably worn and something fouling.
The buzzing is most likely coming from the motor.
I was on the verge of replacing mine with a 'horstman' which i had purchased that fits the existing back plate.
Couple of reasons why I didn't
Terminals on RWB2 on left, those on horstman on right, which makes no difference, except I had tiled around mine,meaning I would have to re position the back plate so left it till the following day.
The second reason was that I temporary replaced the faulty programmer after applying some WD40 and the timer started working again.

 

[Richyyy]

Thanks for the help people. Hopefully saved me a significantly more expensive call out for a professional as long as the replacement works.

 

[Richyyy]

This may well be an intensely stupid question to people who know what they're talking about - how do I tell if my system is 'gravity' or 'fully pumped'? The new controller has a dipswitch to move depending on which it is (the old one doesn't, as far as I can see).

There's a water tank in the loft, but that's about the extent of my knowledge.

 

[MANDATE]

This may well be an intensely stupid question to people who know what they're talking about - how do I tell if my system is 'gravity' or 'fully pumped'? The new controller has a dipswitch to move depending on which it is (the old one doesn't, as far as I can see).

There's a water tank in the loft, but that's about the extent of my knowledge.

I think you'll find the old one does. There's a horizontal slot and in the middle is a 'white coloured programme range adjuster' shaped square with two rounded corners. It has a slot in it and it can be turned so the slot is either horizonal (16 programs) or vertical(10 programs)
However in a fully pumped system you would have either a 3port motorised valve 'T' shaped meaning water would be pumped up and out of the valve to either HW or CH or both.
Or in place of the 3port two 2port valves one for HW and one for CH.

 

[45yearsagasman]

You have a fully pumped system if you have something like these:- View media item 38425 View media item 44939

 

[ianmcd]

when your old programmer was working if you could slide the CH to on without the HW one moving too then you have fully pumped if the HW one moved at the same time its gravity

 

[Richyyy]

Okay, sounds like gravity - thanks again everybody. New programmer arrived, everything working, hot water and heating available again. All for about 45 quid, with the bonus of getting rid of the buzzing noise from the old controller. Perfect.

 

[MANDATE]

What programmer did you purchase for £45 and where from?
Don't think I've seen a siemens RWB2E under £53 inc vat

 

[Richyyy]

What programmer did you purchase for £45 and where from?
Don't think I've seen a siemens RWB2E under £53 inc vat

The one linked earlier in this thread by Hugh Jaleak (RWB29 rather than RWB2E, for what that's worth): http://www.heatingcontrolsonline.co.uk/siemens-landis-staefa-rwb29-programmer-p-43.html

I lashed out on the 3 quid for next-day delivery.