You know, the thing on the wall where you decide what time’s you want hot water and heating to come and turn off.

It depends. Like for like replacement if you can still buy the same model (not as unlikely as it sounds) could be a single screw as they usually sit on a backplate which has the terminal for the cables.

Changing for a different model should just be a matter of working out which cable is which. Then it will likely depend on how clearly the terminals were labelled on the old one.

If you can deal with ring main lighting ceiling roses you should be ok. About same level of complexity.

As above really. Are you incorporating a seperate stat or an integrated one on the unit?

Hmmmm, I fear this may be beyond me, I don’t know what a separate stat or integrated one is and ring main lighting ceiling roses sound like a symptom of plague!

I’ll get on to a sparky. Thanks for the help fella’s.

A stat is the room thermostat. Temperature control basically. Do you have one of these elsewhere in the house already? I’m no sparky but a hairy arse builder and it will make a difference as to what control unit you can or can’t buy I’d say.

I fitted one to my system which previously didn’t have one, just an on/off switch. All I did was cut the cables in line with the switch and connect them to the relevant timer terminals, the the switch just stays ‘on’ and the timer controls everything. Piece of cake.

For replacing an existing one, your biggest hurdle is going to be identifying the existing terminals; if you’re lucky they may be labelled inside the box, or you could google the model to see if there’s a manual online somewhere.

You might find that if you undo the screws at the bottom of the programmer and lift it up that it has a standard backplate which the replacement can be clipped straight on to.

Post a pic.

As others have said, a number of brands use the same back plate. If is a Danfoss or Drayton they will use the same back plate.

Turn off the power, loosen two screws at the bottom, lift the old one off, put the new one on.

If you need to change wiring, best get someone who knows what they are doing to change it.

You are right to be careful – mains voltage at controller.