Be naughty... Immersion Circuit

[Oracle]

All,

I'm sure some have done it, and I know its "against" regs, but...

If you have a dedicated circuit for an immersion, run in 2.5, fused to 16A or 20A, but you need a 3A or 5A supply for a pump or boiler, how many have just taken a feed from the immersion circuit (assuming all the saefety aspects are covered off)?

O.

 

[Andy™]

water heaters over 15l (i think, or it may be 20l?) should be on their own dedicated circuit

and what happens when you then get called back because the boiler 'doesnt work' because they have turned off the immersion switch in kitchen and now boiler has no feed

 

[danny7299]

i try and stick the the regs as much as possible.. other wise i just go home and worry about it!

 

[Bez]

All,I'm sure some have done it, and I know its "against" regs, but...

If you have a dedicated circuit for an immersion, run in 2.5, fused to 16A or 20A, but you need a 3A or 5A supply for a pump or boiler, how many have just taken a feed from the immersion circuit (assuming all the saefety aspects are covered off)?

O.

How would you get around the Installation Certificate, wouldn't you have to lie?

 

[tom1]

i have seen this for towel rads etc. if a 20 amp mcb with 2.5 twin feeds a 13 amp fcu and a 3 amp fcu, for immersion and boiler, pump towel rad etc

putting the letter of the reg aside, what problems could u expect?

 

[Oracle]

This is what I was wondering...

I'm just curious....

I can understand why the regs advise using a dedicated circuit, as you could be using 50% of your ring supply most of the time for the immersion - if it was fed off the ring

But if all capacities/ratings, tripping times, disconnection times, etc complied - then you do have to ask the question - it would be safe. The loads would be controlled - eg a FCU at 13A for the Immersion, and a FCU at 3/5A for the boiler/pump.

You could still issue a cert - you just detail the design/deviation. Last I heard the regs weren't/aren't mandatory (but it is best to comply) ; -)

O.

 

[PC Electrics]

Yes, I do.

Don't see why an immersion circuit can't be treated like any other radial. Most shower pumps or jacuzzi baths don't require more than about 2 amps, so the circuit is hardly going to be overstretched even if the immersion is in regular use. I've never had to do it, but one could even bump the circuit up to 20 amps.

As mentioned above, the primary reason for the reg was to keep the immersion off the ring so to prevent overloading in the days before central heating was common and it was usual to have a couple of radiant electric heaters plugged in (and most houses only had one ring).

 

[Riggy]

I do it as well. Blushing

But not if there's an immersion switch in the kitchen, or if the ring is reasonably accessible, or, or, or............

Applying a bit of common sense to the job in other words. Applaud Smiley

As for lying on a certificate - never ever knowingly do that! There is a box on there for deviations from regs, record the deviation in there. Applaud Smiley

Do it properly nothing is wrong other than a minor deviation from regs, amazingly this alone will not cause it to spontaneously combust as some would have you believe. ROTFWL

 

[danny7299]

Well I guess the regs are only guidance... they are not statutory...

 

[batty]

I would think 50% of immersion circuits are spurred off. I have done it and cannot see a problem with it as long as its not a large load. Immersion takes 12.5 to 13 amps once up to temp it will click in and out. So on a 20 amp circuit they easily gives you 7 amps and generally most Immersions are just a back up for c/heating.

Batty

 

[gordy71]

Sometimes the immersion circuit circuit is a fail safe way to know that you are not going to be overloading a circuit when taking a spur especially if the ring main is of the jb upon jb spiders web type. Nowadays immersion heaters are only used as backups so i think it is often the safest and most sensible option?