UK Should combi boiler be on dedicated circuit.

[GunnerT]

(DIYer first time post) I Purchased a property in 2021 which had just had a full rewire by a reputable company(allegedly) a month before i moved in, previous owner organised and paid for this.
I recently changed my bathroom extractor fan and was surprised to find the fan, bedroom lights, and the boiler were all on the same (6A) circuit. Is this OK?

 

[plugsandsparks]

Its not a technical problem, more a good practice so any faults on the other stuff does not mean you loose the boiler.

 

[GunnerT]

Thank you for your answer, please bear with me as i am bit confused. I had an issue with extractor fan which has an isolator switch so no need to turn off at consumer board. But if i have a problem with lights i would have to switch off at consumer unit and would then lose my boiler.

 

[plugsandsparks]

A fault can occur at anytime, including when on holiday, nothing worse than coming home to a cold house.
What happens is : Breaker trips, you try to reset it, it wont have it, you scratch your head and run around making sure all the lights are in the off position, you also switch the boiler off at the fused spur and of course switch off the fan isolator. You then manage to reset the breaker. You gingerly go around the house trying each light in turn, breaker still OK.... so you turn on the fan isolator and it trips again ..... *ugger... you then go back to fusebox, reset the breaker again and call out an electrician to sort out the fan........
Lights can possibly trip in the off position but its not common, what used to be the case was a lamp would blow and take out the breaker, but it is easily reset as the faulty lamp has blown and no longer an issue.
Nowadays with LED lights, they either fail elegantly or start flashing, rarely blowing the breaker.
Hope this helps.

 

[ferg]

It's safe and compliant to have the central heating on a lighting circuit. Albeit unusual.
On a rewire, personally I would put it on it's own circuit but it's not unusual to have it as a spur on a socket circuit.
I've done a few board changes where the CH is on a lighting circuit though.
Nothing to worry about, I'm sure the guys doing the work had a good reason at the time

 

[brianmoooore]

I tend to group the CH supply with things like extractor fans and if one of those extractor fans is connected so that it switches on with a light, then that particular light will be sharing a circuit with the CH.

 

[littlespark]

I have been on a couple of jobs where a gas engineer servicing a boiler has commented that the boiler was not on a dedicated circuit. One was spurred from a socket, other was on lights.

I tried to tell the customer there was nothing wrong with it like that, but they both insisted.