Spurring a towel rail off an immersion circuit

[sparkwright]

For years I have always avoided adding anything else to an immersion circuit.

From memory I think it states in the On Site Guide water heating circuits should be on their own circuit.

But I don't think there's anything in the regs.

 

[Adam_151]

As long as the circuit would not be overloaded with both items on* (its reasonably likely that both would be used at the same time, for extended times) then I do not see it as an issue

*Unlikely unless your towel rail is >700w, or there's multiple towel rails in a bathroom the size of an Olympic swimming pool, etc

The guidence in the OSG, is suggesting that it should not be on a circuit intended for socket outlets, as there was a nasty practice of just putting them on the ring circuit that served all the sockets in the house

 

[kai]

You might be able to add to an immersion circuit in limited circumstances. The Circuit Cable is 2.5.sq,mm cable or greater + If the Breaker is 16amps, feeding an immersion of 3kW (13amps), you will have three amps max to spare (700 watts max) for the towel rail (use a 3amp fuse connection unit). That appears to be the only case you can safely add to an immersion circuit.

 

[Taylortwocities]

It is a radial circuit, like any other you estimate the total max demand and off you go. Assuming the EFLI and other circuit parameters check out, you could increase the breaker size to 20amps. But as above you have around 700watts to use and most towel rails are less than that.

Two important items to remember - assuming its a bathroom.
1. The circuit wiil need to be RCD-protected
2. Its notifiable work

 

[JohnW2]

Two important items to remember - assuming its a bathroom. ... 1. The circuit wiil need to be RCD-protected ... 2. Its notifiable work

As regards that 2nd point, you presumably meant to say "if it is within the "zones" of a bathroom"? (the RCD protection is required whether it's within zones or not).

Kind Regards, John

 

[OwainDIYer]

I would be cautious - too easy for someone to come along in future and swap the 700 W tower rail for a 2 kW fan heater. Of course they should check the circuit etc but many would assume that one heater can be replaced by another.

 

[EFLImpudence]

We do not have to allow for idiots.

That could happen to any circuit.



There is nothing wrong with adding a towel rail or shower pump etc. to an immersion circuit.

It then ceases to be an immersion circuit and becomes a properly designed suitably rated radial final supplying two appliances.

 

[sparkwright]

Thanks for all reassurances.

Another thing that springs to mind is that an electric towel rail in a bathroom with the flex almost immediately disappearing through the wall into a totally seperate airing cupboard - where the fused spur will be.

Now presumably this all-electric towel rail will still need to be RCD protected, even though there's no controls or flex outlets in the bathroom at all. Just three inches of flex, and a sealed bottom-entry element.

Seems pointless RCD protecting it, but I'm sure you'll agree it still has to be done. No supplementary bonding as far as I know.

(As far as I know all the circuits in the place ARE RCD protected, but thought it would mak a good discussion!)

 

[deadshort]

Hi, it's a requirement of the electrical regulations, not a lot to discuss

Regards,

DS

 

[sparkwright]

Hi, it's a requirement of the electrical regulations, not a lot to discuss

Regards,

DS

Of course there is.

Just wait for the rush...

 

[deadshort]

Ye, about seatbelts and grannys phone number



DS