3 kW heater switch getting hot!

[Dozy Danum]

Hi, new to the site.
After some advice please.
I had a new conservatory built 2 years ago and decided to have a 3kw wall heater fitted which is hard wired into a fused switch (13 amp) this is on a ring circuit which also has 4 double sockets (these mainly used for lamps and very occasionally my son's game console and TV). This comes from consumer unit with a 20amp mcb. I noticed the other day the heater switch is getting very hot.
I've read on here and other places that it could be loose connections inside the switch or because a cheap switch was used, but I'm concerned the circuit may not be up to the job. The sparky who fitted it said it was ok as the heater came with a 13 amp plug which could have just been plugged into one of the sockets, which i suppose makes sense.
I think I just want someone to tell me what he's done is ok.
If so I can get someone to fit a better quality switch and make sure the connections are tight.
Thanks.

 

[winston1]

Most likely the heat is from the 13 amp fuse rather than the switch. Fuses do get hot at their maximum rating, do changing the FCU probably won't help. What brand is the FCU out of interest?

 

[EFLImpudence]

Change the fused switch to just a 20A (unfused) switch.

It doesn't need a fuse.

 

[Dozy Danum]

Cheers Winston.
I've just had look and there is no name on it. However there is a crack on the face between the red light and the switch. As it was only done 2 years ago I'm assuming it is a cheap one. My fault, the electrician probably did asked me if I wanted a certain make of switches/sockets and I remember I just said white.

 

[winston1]

Change the fused switch to just a 20A (unfused) switch.

It doesn't need a fuse.

I think you will find the manufacturers and most sparks will disagree. Is the cable on the heater likely to be rated at 20 amps?

 

[EFLImpudence]

It doesn't have to be.

The heater is 12.5A and will not overload. Immersion ???

 

[winston1]

Don't know what immersion has to do with it. Suppose the heating element failed with age and a broken end dropped down and shorted part of the element.

 

[EFLImpudence]

Don't know what immersion has to do with it.

Do you recommend a fuse for immersion heaters?

Suppose the heating element failed with age and a broken end dropped down and shorted part of the element.

Do you mean the circuit being completed through the CPC rather than Neutral?

What do you think would happen?

 

[winston1]

Immersion heaters are not on 20 amp circuits.

I never said anything about CPC. I said shorted part of the element. The element is connected between live and neutral.

 

[EFLImpudence]

Immersion heaters are not on 20 amp circuits.

They could be.
Are you not frequently saying - correctly - that the fuse/MCB protects the cable; not the appliance?

I never said anything about CPC.

No, but that's what would happen if the end of the element contacts the body or reflector of the heater.

I said shorted part of the element.

The element works by being "shorted". Please be more specific.

The element is connected between live and neutral.

Not if one end falls and contacts an earthed part.

 

[OwainDIYer]

Doesn't everything on a standard ring final circuit have to be connected with a < 13A fuse (or other cutout)?

 

[EFLImpudence]

No.

 

[Iggifer]

Doesn't everything on a standard ring final circuit have to be connected with a < 13A fuse (or other cutout)?

Might be relevant, but it's a 20A radial final circuit in this case

 

[Dozy Danum]

Thanks EFL.
So that should sort it then? The odd thing is since I had the conservatory done I've had a new main consumer unit fitted and the electrician (a different one) had to check all the sockets/switches in the house to make sure everything was as it should be and he signed it off ok.
So do you agree with Winston then it's the fuse and if it doesn't need one then the switch shouldn't get hot?
Wonder why he fitted one with a fuse in the first place? (Unless that's all he had in the van!) Surely not

 

[EFLImpudence]

So that should sort it then? The odd thing is since I had the conservatory done I've had a new main consumer unit fitted and the electrician (a different one) had to check all the sockets/switches in the house to make sure everything was as it should be and he signed it off ok.

It would have seemed alright.

So do you agree with Winston then it's the fuse

Yes, it may be the fuse - or a loose connection.

and if it doesn't need one then the switch shouldn't get hot?

Correct. It really doesn't need one.

Wonder why he fitted one with a fuse in the first place? (Unless that's all he had in the van!) Surely not

It's just what people do because people just do.[/quote]