immersion heater wall switch.

[anna1982]

I am arranging for the electric switches /sockets in my property to be changed, however looking at the range i am going for, i am trying to establish what ones i need to order for my immersion heater. (they will be fitted by a friend of family who is an electrician but i am ordering the switches, spurs etc ready for him to fit). Unfortunately he is away for a few weeks on holiday so can't contact him until he comes to fit them, the current wall switch is switch with a neon and a built in fuse.

The range that i am intending to order from does several versions, one with a neon and fused (13amp) and also does two other options, 20A double pole switches (non fused) and 45A Double pole switches.

As the existing one is fused does it mean therefore i would need to order the fused one or would i be able to use one of the other two either?

 

[EFLImpudence]

You need a 20A double pole switch - No fuse.

 

[Steve]

You need a 20A double pole switch - No fuse.

The one she has now is a fused switch - shouldn't she order like for like?

 

[securespark]

Unfortunately he is away for a few weeks on holiday

In my next life I am going to be one of these highly paid, eternally-holidaying sparks!

I have seen immersions in 1960's properties coming off the ring with a fused connection unit.

If this is the case, you will need the fused one. But you won't be able to tell before Loadsamoney comes back off holiday.

 

[EFLImpudence]

No. immersions do not require and should not have a 13A fuse.

I am assuming it is a conventional 16A radial circuit.
Even if it isn't it should not be on an FCU or plug.

 

[winston1]

As we don't know where it is fed from, ring or radial, no one can answer your question. Safest way is like for like. Although immersions do don't conventionally have 13 amp fuses no harm will come from having one.

 

[EFLImpudence]

I suppose that is wise under the circumstances but it is going to be done by an electrician.

Unless something really weird has been done, then it doesn't really matter, does it?

Even if it is on a ring circuit, it will probably be wired with 2.5mm² spur - but 1.5mm² wouldn't matter.
Fuses are to protect the cable - not the immersion which cannot overload the cable so, either way a fuse is not required.

Even if it were on 10mm² cable with a 60A OPD, a fuse is not required.

 

[deadshort]

I am arranging for the electric switches /sockets in my property to be changed, however looking at the range i am going for, i am trying to establish what ones i need to order for my immersion heater. (they will be fitted by a friend of family who is an electrician but i am ordering the switches, spurs etc ready for him to fit). Unfortunately he is away for a few weeks on holiday so can't contact him until he comes to fit them, the current wall switch is switch with a neon and a built in fuse.

The range that i am intending to order from does several versions, one with a neon and fused (13amp) and also does two other options, 20A double pole switches (non fused) and 45A Double pole switches.

As the existing one is fused does it mean therefore i would need to order the fused one or would i be able to use one of the other two either?

If you look in your fuse box you will have a fuse or Circuit breaker marked immersion or water heater. If you do then as has been advised a 20a DP switch is required. If you don't and the immersion heater is wired to the sockets you need to replace the existing with a fused 13a FCU.

DS

 

[EFLImpudence]

If you don't and the immersion heater is wired to the sockets you need to replace the existing with a fused 13a FCU.

Why?

 

[winston1]

If you don't and the immersion heater is wired to the sockets you need to replace the existing with a fused 13a FCU.

Why?

Spurs off a ring either go to sockets or FCU. Appliances are not connected directly to rings without fusing down.

 

[EFLImpudence]

Appliances are not connected directly to rings without fusing down.

The purpose of that fusing down is what?

 

[winston1]

Are you a sparks? Ever heard of safety?

 

[EFLImpudence]

Forgotten ?

The fuse is to protect the cable not the device on the end of it.

433.3.1(ii)

 

[jg321]

I have seen immersions in 1960's properties coming off the ring with a fused connection unit.

I've seen early an early 80s property with the immersion on the ring on an FCU. My current property (2008 ish flat) has a dedicated 20A circuit for the immersion, but then has a switched FCU before the control unit.

This latter example seems odd to me, but it's used every night (no gas here), without any issues (so far).

 

[EFLImpudence]

Yes, I have also seen one with a socket, plug in timer and plug which has been there for ever with no problems.

I have also seen all three in various places burnt out.
Sometimes 13A accessories and fuses don't like immersions - depends on quality I suppose.

If there is no electrical reason to use them then there is no point using them.