cable size for central heating

[soloheadbeg]

Hi

I am moving my simple APT electromechanical timer from the boiler house into the main house. The run from the power to the switch and back to the boiler is about 30 metres. The circuit will power the pump tthe boiler and the timer. i have laid 1.5mm2 twin and earth. Is this cable size ok.? I presume it's plenty as the current drawn from the above should be quite low.

Cheers

 

[flameport]

Size is fine, if anything it is too large, 1mm would be ok.

Is this just a single length of T&E - because any timer will require more cores than that.

 

[JohnW2]

I am moving my simple APT electromechanical timer from the boiler house into the main house. .... i have laid 1.5mm2 twin and earth....

What exactly do you mean by 'laid'? - i.e. how does this T&E cable travel from the main house to the boiler house - overhead, underground or what?

Kind Regards, John.

 

[soloheadbeg]

Hi lads

Appreciate the fast reply. When I say laid all I mean is I have run the cable along inside wall of garage into the attic space of house and dropped it to where I will locate it in house. My consumer unit is quite close to the boiler so my cabling effectively has to come from there to the switch in the house and back to the boiler. My main concern is the cabling size.

Thanks a lot.

 

[Steve]

My main concern is the cabling size.

Our main concern is the number of cores. What connections do you require?

 

[soloheadbeg]

Hi Steve

This is an old central heating system which is either on, off, or on a timer. The system incorporates no motorised valves, room stats or cylinder stats. The plumbing will not allow hot water only. So you can see that all I really need is a twin and earth in to the timer and a twin and earth out of the timer and back to the boiler, pump etc. You might also advise me on the correct current raring for the fuse in the FCU which I propose to protect this circuit with. I think either a 5 or 3 amp?

Again I'm delighted with your help on this project.

Cheers

 

[EFLImpudence]

You really could do with a room thermostat.

Have you thought of a remote programmer/timer/thermostat.

You would just put the receiver where the present timer is and the programmer any where you want. No wiring.

 

[soloheadbeg]

Thanks for suggestions. I realise that the system is not ideal but I'm bringing the timer into the house for an elderly relative who has difficulty accessing the timer in its current location. She has no interest in updating the system. As regards the radio controls I think they're a great idea but unfortunately my elderly relative can just about get her head around how to operate an electromechanical timer and getting to grips with operating a digital timer would be quite a challenge.

Any advice on the fuse rating for this circuit?

Thanks a million for your help.

 

[EFLImpudence]

my elderly relative can just about get her head around how to operate an electromechanical timer and getting to grips with operating a digital timer would be quite a challenge.

Yes, I have one like that.

3A fuse will be fine.