New Grant 50-90 Euroflame boiler-truly ancient timeswitch

[McBride]

I had the boiler replaced 2 years ago but not the clock. This is a real newbie question so be easy on me..

I want to replace the clock and I have a fair confidence in electrics but I' ve heard horror stories about the importance of matching up the wires. I haven't taken apart the ancient time (30 years +) dial clock, which has 'Lee' and a serial no written on it, because I don't want to put te CH out of commission before I know how to replace it.

My question is, surely there are only 3 wires from the mains that I need to connect to the timeswitch?

 

[breezer]

there will be more than that.

a basic timer has supply in -L,N,E

supply to boiler L,N,E

thats 6 wires


why not have a look and see how yours are connected.?

 

[McBride]

So, that's the usual 3 in(to the timer) then same 3 back out to the boiler?

Like I say I don't want to take the CH out of commision for as long as i can afford to.

 

[breezer]

no.

the cable to the boiler will only become live when the timer tells it to.

but las i said open yours and have a look