What is this attached to my central heating timer?

[candyjet]

I have a 40 year old oil fired central heating system, with a potterton timer, underneath which there is a white box with some sort of copper wired electrical device.

The timer is broken and I want to replace it, but before I do, I think I should find out what the component is.

I hope that there should be a picture if you go to this link

http://hometown.aol.co.uk/tcgales/myhomepage/photo.html

The question is, what is that bit?

Thanks

Tony G

 

[oilman]

It's a relay in a box. Homemade job, and a good idea. Don't chuck it, it is used to switch the load which otherwise gets switched by the programmer. Don't let any "professional" chuck it out either. If they try, they don't know what they're doing, despite what they might tell you.

 

[candyjet]

Thanks for the reply.

I was thinking of getting a Seimens timer. Will the wiring to the relay and timer be similar to the Potterton?

Thanks again,

TG

 

[oilman]

Probably.

What about a timer for the hot water, and an optimising programmable thermostat. It will actually save you money. (Honeywell CM67)

 

[fireman22]

i`ve done this myself, but used right sized enclosure to house relay.
The relay is switching the load or it is being used to stop feedback to keep heating and hot water seperate. Any digital or mechanical programmer will do the job as contacts only switching load of relay coil.