Heating timer - how to take it off backplate???

[steve.chambers]

I have a Horstmann Channelplus XL heating timer. The timer is maybe about 4 years old. It has inexplicably gone wrong and the display has gone blank. Would like to have a look to see if it's just a simple wiring problem but I can't seem to open it up. I've unscrewed the two screws at the top and then thought it would be a simple case of removing the timer from the backplate but no. Have really given it quite a lot of force but it just doesn't come free.

One thing to mention at this point is I'm being a bit naughty and not disconnecting the elecrical supply first. So many electrical things in my house and I just don't want to have to reset the times & programs on them all if I can avoid it, also not sure which fuse it would be on. Guess you'll all come down on me like a ton of bricks for that but it really shouldn't be a problem as I'm not touching any wires by opening it up to have a look. (Course I'd switch the electricity off if I actually need to do any work on it.) So that's part of my question really, could it be that having electricity connected means you can't take the timer off or is it something else I'm doing wrong? Cheers for any advice.... Steve

[Palindr☻me]

The basic problem of opening anything with power on, where you don't know what is inside, is that you could move something into contact with something else, or very close to it - as you pull it apart.

Also, sometimes leads pull off/out when you open boxes. The connections may be in the top plate, but whoever installed it pulled back all the slack after connecting the wires and mounting it. Silly, but it happens.

Mine is on its own circuit - and thus I wouldn't have to go anywhere near the easily-identifiable main ring main fuses, to find which fuse it is on. At worst I would put some lights out, not reset anything electronic.

No ton of bricks. If you short out something in a box in your hands a few inches from your face, the odds are that all that will happen is the fuse blows. A risk any gambler would be happy to take.

OK, so you get it open. What then? Unless you are an electronics engineer/technician, you probably won't be able to mend it. Wiring problems seldom happen to fixed wiring, IME. Only to flexes and other things which have mechanical forces acting on them.

So, I would suggest going back to your consumer unit, identifying all the circuits it couldn't be by the fuse ratings (eg ring mains, cooker, electric water heater, off peak storage heating, whatever) and try the ones that are left. Take a torch.

Then, when you are sure the power is off it - pull away.

[Peter Andrews]

Sue's right but there is an installation guide at

Peter