Consumer unit full

I did wonder if that's why the electrician suggested a single pole when reading your other thread!

Its good practice to have the heating on its own circuit. Usually a radial protected by a 16amp breaker and then fused down to 3amps for the flex going to the boiler.

 

Mate, I'm pretty sure immersion heater ctts are only allowed to supply the immersion heater and nothing else. Might be worth a check. Personally I would have the immersion on it's own ctt and the boiler off a spur from the ring final.

 

Col, going by the letter of the regs. yes immersion heaters should be on their own dedicated circuit. However, I can't see anything wrong at all with spurring off via an fcu with a 3 amp fuse, rightly or wrongly I admit I've done it a few times! (and certified it) This is why the regs. are not statute I think, as competent people we are allowed to make decisions on our own as to what's safe or un-safe?

 

^That's a fair point mate, and prolly I would do the same if I had no other choice, but I'm just sayin' like

 

Hi Seneca

Are you sure you've had an immersion heater on a 3 amp fuse? Boiler circuit maybe.

Kind regards

BS

 

FCU with a 3 amp fuse spurred off of the immersion circuit to feed the boiler!

 

Cheers Seneca. Re reading it I can see what you meant. First read looked as though the immersion heater not the boiler was on the FCU.

Note to self - Must read things more clearly before querying.

Kind regards

BS

 

I'm happy with 1mm cable on 6A MCB fused down to 3A for a boiler circuit.

 

1mm now only to be used on lighting circuit's Stateit!
When I install a boiler circuit from scratch I use 1.5mm and a 6 amp mcb and then an fcu with 3 amp fuse near the boiler.

 

Blimey. I'll have to look that one up. Regs book in my van at the moment as had assessment 2 days ago.

Shame I wasn't asked that question as I'd have argued till I was blue in the face...

(Max 3A load on single point circuit with cable able to take more...)

 

Mad isn't it Stateit, 14a rated cable with 3a fuse isn't good enough for them and yet we can still have a double socket outlet spurred from a ring or c/unit with 32a mcb on 2.5!

 

Yep, 1mm for lighting only. Room stats, fans from FCU's on a socket cct etc all need to be in a minimum of 1.5mm.

I don't think it was fully thought through.....

 

Nothing new there then Lec!

 

I was thinking how daft some of this stuff is recently whilst installing an outside double socket outlet for someone. It was a very easy job, the c/unit was on the inside of the wall where I was fitting the socket. I planned to spur the socket from the ring at the c/unit but I noticed a 32 amp radial circuit which was only feeding the boiler through an fcu. I thought how much more sensible it would have been to put the outside socket on there but of course I wouldn't put a 2.5mm radial on a 32 a mcb would I, but putting the outside socket on a 2.5mm radial from the 32 a ring circuit is fine!

 

I can remember a discussion with the NICEIC assessor inspecting a PIR we did (we get assessed on these too, and full day inspection).

I had commented on two separate hand drier circuits being fed from a single B32. The hand driers in 2.5mm, and with DP switches (not FCUs).

The assessor asked "how would you remedy this". I replied with "swap the MCB for two 16 or 20amp MCBs and swap the DP switches for FCUs. He replied with "or just swap the DP switches for FCUs".

I was quite early in my sparking life, and it highlighted a practical difference between short circuit and overload protection, when compared to a classroom!

 

You guys are kidding me? Your not wiring every "power" ctt. in 1.5mm from now on off a 3a fcu? Even boiler controls?

 

If you want to comply.....