No spare way

[ajsdoc]

Hi,

I'm looking to upgrade my central heating system. Currently I have no immersion and thought I'd have one put in as a back up for if (when) the boiler breaks down one day in the future.

I have what I believe to be a split load consumer unit, but when I look every MCB is used with none spare. Does this mean adding an immersion will need a whole new CU upgrade (it doesn't look that old, but was fitted before we moved in 4 yrs ago)?

Will there be ways round this or do I need to also factor the cost of a new CU in too?

All advice appreciated.

 

[RF Lighting]

If there really is no spare ways, then an electrician can add a small additional CU for your new circuit.

Just because there is a circuit breaker in every slot in your existing CU, doesn't mean they will all be in use.

 

[ajsdoc]

Thanks, they are all labelled as being in use.

One is for the doorbell and seems to go to a transformer. I'd thought I could easily lose this and go for a wireless bell if that's easier but the bell works so if a small CU fitted alongside does the job that seems to make sense.

Thanks again.

 

[RF Lighting]

If the bell is on it's own circuit, this could be doubled up with a lighting circuit to free a way up in the existing CU, which will save a fair bit of faffing around with extra CUs etc.

 

[ajsdoc]

Thanks, appreciate you taking the time.

 

[winston1]

You could put the immersion on a FCU off the upstairs ring. Not conventional but as it will be rarely used it should be OK.

 

[Taylortwocities]

You could put the immersion on a FCU off the upstairs ring. Not conventional but as it will be rarely used it should be OK.

True its not conventional, but guidance is against doing this.

The On Site Guide and the Electrician's Guide to the Building Regs both recommend that a water heater with a capacity of more than 15 litres should have its own circuit.
Also Appendix 15 of BS7671 suggests that fixed loads of more than 2KW should not be connected to a ring final and should have their own circuit.

So, its not a regulation, but there's a lot of advice that its not the best thing to do.

I'd move that bell transformer to share one of the lighting circuits and follow the guidance and give the immersion its own circuit.