Replacing central heating timeswitch - Landis & Gyr RWB

[mjt81]

Hi Folks,

I currently have a Potterton Puma 80 which has made it to the grand old age of 19 and is still going strong (touch wood) even if it is somewhat on the noisy and most likely highly inefficent side!

Anway - it currently has an external electronic timeswitch for the central heating fitted - Landis & Gyr RWB270. I should add at this point that there is no room stat fitted, its just a timeswitch.

I wanted to replace it with a more functional timeswitch to allow 7 day programming.

I was looking at the Hortsmann C27 as it seems to be cheap enough and gets decent reviews, can anyone confirm if swapping one with the other will be pretty straightforward as far as wiring goes? Or would anyone suggest a different timeswitch?

Cheers!

 

[Whitespirit66]

The Siemens RWB29 is a straight swap for your L&G. Use the existing backplate and wiring.

http://www.heatingcontrolsonline.co.uk/siemens-landis-staefa-rwb29-programmer-p-43.html

Most standard two channel programmers will also replace your existing unit, inc the Horstmann. Just make sure that the timing options of any new programmer are suitable for your needs.

 

[mjt81]

Thanks whiteSpirit - for the sake of a fiver I may just go with the Siemens you suggest if its gona be a simple straightforward swap

Cheers!

 

[mjt81]

Just realised - its clearly not a 2 channel controller I need - its a one channel - exsitsting controller is an L&G but not eh model listed above - identical but only 1 channel. Based on this revised knowledge any suggestions for a one channel controller, or could I still use the two channel, but just wire up for CH and not DWH?

Cheers

 

[Whitespirit66]

Sorry, your suggestion of the Horstmann c27 threw me. Ignore above.

As the C27 is two channel, it's not suitable. You have a combi, so you need a timeswitch. You could either just add a time switch, or adding a programmable room stat would be advisable.

Timeswitchs -

http://www.heatingcontrolsonline.co.uk/danfoss-randall-ts715-p-155.html

http://www.heatingcontrolsonline.co.uk/acl-drayton-invensys-lifestyle-lp711-timeswitch-p-186.html

Programmable Room Stats -

http://www.heatingcontrolsonline.co.uk/danfoss-randall-tp5000-p-132.html

http://www.heatingcontrolsonline.co.uk/danfoss-randall-tp7000-p-134.html

http://www.heatingcontrolsonline.co.uk/honeywell-cm907-day-programmable-thermostat-p-271.html

 

[mjt81]

No problems whitespirit - my fault for giving duff info in the first place!! thanks for your help - might well look into a programmable thermostat as an alternative, as it would be nice to have a room stat too, although the wiring might be a bit of an issue, perhaps I'll look at a wireless option so I can have the 'box' by the boiler then plonk the stat in the living room/hall/wherever without having to mess about with hard wiring it!

 

[Whitespirit66]

If you're using wireless, try to go for the best one that you can afford. Something like a Honeywell CM927 or Danfoss TP7000 - RF. When you choose your stat, someone on here will be able to advise on wiring.