Installing Honeywell ST6400C 7day programmer

[HokkaHokka]

Hello,

I have an old but unused ST6400c that I would like to use to replace my old Honeywell which is faulty.
I'm not an electrician or experienced at all with wiring but is this a relatively straightforward job and if so can you please give me any pointers?
Thanks
HH

 

[ericmark]

It seems it uses are reasonable standard plate, terminal 4 is central heating on, terminal 3 domestic hot water on and if you need DHW off that is terminal 1. It may even fit the same back plate.

However in the main we have stopped using programmers, as we can get hard wired programmable thermostats for around £35 and with a well insulated DHW tank there is no real reason to turn off DHW.

There are exceptions where there is no tank thermostat for the DHW and only control is if boiler runs or not. But just been setting my central heating, and 17°C over night then in morning raises 0.5°C every 2 hours as thermostat is in the hall so want to ensure heating runs so the TRV's can set room temperatures. So around 6 temperature changes through the day, but programmer only allows on/off.

 

[DetlefSchmitz]

However in the main we have stopped using programmers, as we can get hard wired programmable thermostats for around £35 and with a well insulated DHW tank there is no real reason to turn off DHW.

Speak for yourself. I, for example use one to turn off the water heating during the day, so that the solar thermal can do it for free.