How do I take this thermostat off the wall to renew it?

Or are we waiting for your friend Ben Doon to come along and shout "troll!"

On the bottom edge should be, either, two slots that you stick a flat screw driver in and release the front, or two screws that you turn to release the front.

I had exactly that model. I seem to recall some difficulties working out the securing mechanism, so I removed it with a lump hammer. Unfortunately, I can't remember the "correct" way to remove them, although it was obvious at the time from the remaining pieces.

However, you should note that it isn't a thermostat, but a central heating programmer. You might also want to do some sort of fault finding investigation, rather than just replacing components randomly.

Christian.

Look for some small screws underneath, they slacken then the whole thing rotates around the top edge disconnecting from the backplate. This is not a themostat it is a timer/programmer.

If you look underneath on the right, you'll see a tab the same colour as the front. Push this up with a screwdriver, and hinge the light coloured front upward.

However, it's a programmer, not a thermostat. And if the lights work as normal and you can hear the relays click if you toggle the buttons to alter the state, I'd say the problem is likely elsewhere.

SNIP

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