Flex cable location around immersion heater

My parents got their water tank all urgently replaced there by a plumber at the weekend, after it leaked everywhere. Plumber didn't wire in the immersion heater part, understandably. I have experience and can wire an appliance to a fused spur no problem. Wiring it isn't the question, I am just not sure what I am supposed to do with the flex cable. I have the cable and fused switch spur, which plumber got for her.

Original spur is old one with no led or fuse, so will be replacing that. Not really sure how I can clip it to anything, is it fine to be just hanging over the tank, as, not sure if you can see from picture but it goes in through the front section there. I mean, there is no real heat off the tank anyway because the insulation is so good on the tank, but still was surprised. Was thinking flexi conduit or something, or is that just way OTT ? Kind of awkward with the location of the pipes etc.

Pic below, old switch on left. Thanks.

 

Normally heat resistance flex is used.
Nothing more required.

No fuse required. It will only overheat.

 

The heater should be fed from its own 15/16A circuit on the fuse board, if this the case you need a 20A double pole switch at the heater. The spur is not required as it will be over loaded.

 

As above. Use a 20A switch - with neon or not.

You could hang the flex from a cable tie loose around the crossed pipes just to keep it out of the way - otherwise it doesn't matter.

 

lag the hot pipes (you should do that anyway)

You can clip the flex to the wall, and arrange it so it runs to the immersion heater without touching any pipes. You can loop any remaining slack in a convenient place and clip it to the wall.

You reason you don't need, and should not use, a fused switch (FCU, or "spur") is that the immersion heater circuit is (should be) a dedicated radial circuit, with a 16A breaker or fuse (possibly 15A if very old) in the consumer unit. This circuit should not be supplying any other outlets.

 

I would be wagging my finger at the person who cut the flex from the DP switch & left it sticking out like that.

 

Where did you get that understanding from

 

No need for a neon either. Just a waste of electricity, all being a small amount.

 

you cannot be serious.

electricity used by the neon is imperceptible and will only occur when the switch is on.

Which you cannot say for what the immersion will use, if it is inadvertently left switched on.

The neon (LED these days) may alert the user.

 

I did say "a small amount".

 

Leaving an immersion heater ON while you go to Spain for a couple of weeks is not a small amount, a neon could have alerted a person to turn it OFF. I wouldn't have thought the idea of providing a neon would have such difficulty getting into someones head.

 

Well, if it were visible in a conspicuous place you might be correct.

However, under a shelf in the airing cupboard above a switch in the on position, I don't see how it would help.

 

I agree, neons are much more effective when they are visible.

Then why did you suggest it?

 

I did not suggest it.

 

Of course you didn't