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Replacing Room Thermostat

I would like to replace my old room thermostat (mechanical dial type) with a new programmable electronic one. Can anyone advise whether this is a 'simple DIY job' or whether i need the services of a 'competent professional' to avoid burning the house down?



  • sdd7677
    sdd7677 Posts: 128 Forumite
    You need to get in touch with plumber who do electric stuff too
  • jrrowleyws
    Its just a thermostat and not a timer? If so, take a look at wiring diagrams between your current one (or similar) and a programmable one. I'd guess the wiring would be the same as its essentially doing the same job just with a different interface.
  • ormus
    ormus Posts: 42,714 Forumite

    there is a universal backplate system. most (modernish) programmers follow the same format. they are effectively interchangeable.
    Get some gorm.
  • Bikertov
    Bikertov Posts: 1,598 Forumite
    First Post First Anniversary Combo Breaker
    So long as you feel competent with electrics, it is not that much more difficult than changing a light switch for a dimmer switch.

    A thermostat is basically a switch that works on temperature. Be it a 'mechanical' one with a dial, or a snazzy programmable electronic one, it is still a switch of sorts.
  • jcb208
    jcb208 Posts: 751 Forumite
    First Post First Anniversary Combo Breaker Mortgage-free Glee!
    Simple if you have basic electrical skills, only 2 wires to connect, live and common, just tape and do not connect earth and neutral from your old thermostat if present
  • gteuk
    gteuk Posts: 6 Forumite
    It is pretty simple but varient on what type of programmer you are looking for, thermostatic controllers come in many variations, the old dial ones are just a fancy relay switching the live, now there are more complexed ones.

    I have designed one for use with electric underfloor heating which can have upto 8 wires connected to it.

    Before buying you controller check out the installation instructions most online sources should have them as downloads, it is also important to ensure it is rated correctly, if for standard gas central heating most controllers will be suitably rated.

    Some of the old analogue dials had a seperate timer in the kitched, does yours ?

    For replacement of an existing fitting an electrician is not required, however you must be deemed as a competant person (whatever one of them is?)
  • mahatma_andy
    Thanks for the replies. It is just the thermostat i'm looking to replace - the existing programmer that controls the heating and the water is staying. I'll take the existing thermostat apart and see what wires are in there.
  • mahatma_andy
    I've had a look in the existing thermostat. There are 4 wires, connected as follows:

    Brown - connected to LIVE
    Blue - connected to NEUTRAL
    Green/Yellow - connected to EARTH and
    Yellow - think this is the switched live?
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