bizarre immersion setup

[wahee]

hi

I have a house form the 1930 which has a double switch immersion setup.
The tanks seems to have one long single immersion heater unit rather than 2

In the kitchen there appears to be a double pole switch, with 2 lives and 2 neutrals.

On the upstairs landing there is a isolator switch with a neon.

The kitchen switch neon lights up when on and turns off when switched off. There seems to be power coming into the isolator switch when the kitchen switch is on.



The isolator switch does not seem to work and the neon won't light.
The immersion does not get warm

However when the isolator is switched down the kitchen neon lights and the kitchen switch seems to have no effect

I was wondering if anyone has any experience of this kind of immersion, a wiring diagram or some info on the connection in the isolator. I have asked a friend who is an electrician to look at it but he is stumped too

Untitled

• wahee
• 17 Apr 2013
• 1

attached is a pic of the inside of the isolator


many thanks

 

[flameport]

The usual deal is that when both of the switches are on, the heater heats the water. If either or both are off, the heater is off.
This enables the heater to be controlled from either location, making it more convenient to switch on/off from the kitchen when washing up, or upstairs when using the bath.

Probable that one of the switches has failed, or the heater element has failed. Both could be checked in 2 minutes by any decent electrician.

I have asked a friend who is an electrician to look at it but he is stumped too

They are not an electrician. Find a proper one.

 

[securespark]

Yeah, I saw one of these once, but did not spend time looking at it sadly.

How many wires are coming in at the switch near the immersion?

 

[wahee]

The usual deal is that when both of the switches are on, the heater heats the water. If either or both are off, the heater is off.
This enables the heater to be controlled from either location, making it more convenient to switch on/off from the kitchen when washing up, or upstairs when using the bath.

Probable that one of the switches has failed, or the heater element has failed. Both could be checked in 2 minutes by any decent electrician.

I have asked a friend who is an electrician to look at it but he is stumped too

They are not an electrician. Find a proper one.

hi many thanks for the feedback. Yes the bottom switch seems to be ok. I'll check power at the isolator and trace where it stops. I suspect the switch. I was thinking of just bypassing it with a blanking box or wiring a new 45 DP straight to the immersion heater. I have yet to check this, although according to the previous owners it was working ok.

 

[wahee]

Yeah, I saw one of these once, but did not spend time looking at it sadly.

How many wires are coming in at the switch near the immersion?

hi

there is 2x lives and 2 x neutrals coming in at the bottom. I think these must go/return from the DP switch in the kitchen.

1x L & 1xN coming in at the top. Live feed from fuse box.

1x Blue N and 1x brown L. Probably going to the immersion.

I need to check this with my meter but it seem to fit the picture.


The isolator I think is just a piece of copper. I'm not sure if there is a fuse in it.

regards

 

[stem]

There are some clues in the photo. The switch is marked "2 way switch" and the live wire (brown) feeding the the immersion is connected to a black wire, suggesting that the black wire is being used as a live.

Therefore, I believe that it was originally a two way switched system allowing the immersion to be turned on or off upstairs or down, regardless of the position of the other switch. The clue here is that the removable isolation link is required in case someone turns it on downstairs during maintenance.

Based on this, the original set up would have been.

Untitled

• stem
• 19 Apr 2013
• 1

My guess is that the downstairs switch has failed at sometime and someone has changed it for a standard double pole isolator, rather than a two way switch and wired it goodness knows how and that is why it no longer works.

The difference with this arrangement to the traditional one flameport mentions is that both switches don't have to be 'on' for the immersion to work, it can be operated from the top or bottom just like the lights on a landing.

 

[wahee]

hey that is fantastic! You effort is much appreciated. It makes sense now.
The downstairs switch has been swapped for a standard double pole switch which would have resulted in no + going to the heater +

When the switch is thrown The live goes to live and N to N

I will see if I can locate a decent 2 way immersion switch to replace it with.
It may be a hard item to obtain of the correct amperage

 

[stem]

Probably the easiest way would be to buy a two gang MK Gridswitch (other brands are available) and put a 20A two way switch in one gang and a neon in the other.

There doesn't appear to be a neon upstairs, so you might consider fitting one in place of what looks like a blanking plate on the right hand of the upstairs switch. As it will be a two way switched system you can't rely on the position of the switch to know when it's actually on.

Also, I don't see any earths I hope they are there somewhere.

 

[RF Lighting]

MK do a 20A 2 way grid module part number K4892 WHI

You will also need a 1 gang grid plate and yoke to go with this.

I'm not aware of an off the shelf 20A 2 way switch.

 

[wahee]

MK do a 20A 2 way grid module part number K4892 WHI

You will also need a 1 gang grid plate and yoke to go with this.

I'm not aware of an off the shelf 20A 2 way switch.

hi yes I have been searching and found only large outdoor type of waterproof switches which may look a bit OTT

I shall order the MK kit and hopefully solve my issues. Thanks very much

 

[kai]

Having a fuse unit may be a good idea for isolation (the original switch had a pull out isolation link too).

 

[HERTS P&D]

How old is the wiring in the property?

It might need updating.

Andy