Central heating timers - which one?

[A.Lee]

Next door to me want me to fit a new central heating timer/programmer for them, as 'I am handy' (and cheaper than getting someone in to do it).

They have a Baxi back boiler. Easily 20 years old, probably over 30yo, with a really old dial type timer, which has stopped working altogether, just the on/off switch now works.

This one at Screwfix seems to be the one I'll need:

Am I right in my thinking that this one will be suitable? It may help that they think they have a wiring diagram for the old one, which will make things a little easier if they find it. Thanks Alan.

[RobertL]

I used a horstman timer for a long time and found it good and reliabale and the batteries lasted for ever.

BUT be careful you don't get something too complicated for them or you'll be summoned round there every time they want to change the programme.

Robert

[Owain]

One caveat is that with a system this old the hot water might be gravity fed, and is very likely required to come on for the heating to work (ie heating and hot water are not completely independent. I can't remember which Plan this is but the interlocking inside the programmer may need altering to suit.

Owain

[Roger Mills]

Yes that one will do. It's quite likely - though not certain - that your neighbour has a system with gravity HW and pumped CH, so you need a programmer which can cope with that. The one you suggest certainly can - but so can electronic timers such as

[1] I would personally go for an electronic one rather than a mechanical one if you think your neighbours can cope with it ok.

[1] the Screwfix description doesn't explicitly say that it's suitable for gravity systems, but if you click on the Instruction Manual link, it's clear that it does.

[A.Lee]

Thanks for the replies everyone. The simplicity of this one is what caught my eye. They cannot change a bulb themselves, so working out a digital timer is likely to be beyond their realm, hence the easily seen on/off clips on the clock face are ideal. Thanks Alan.

[geoff]

There are interlock pins on the sliders themselves on the tiara for doing this

[geoff]

In message , A.Lee writes

The Tiara is also a really old dial type timer (but functional)

It has isolated switches (i.e. not connected to live like many are) and so would be suitable for any application

The backplate will probably need changing

Normally on the back of the timer itself ...