Fused Boiler Isolation Switch

[JamesK]

Hi All,

On a recent service visit by British Gas they commented that my boiler, located in my kitchen didn't have a fused isolation switch. They recommended I go and buy a switch with a 3A fuse in it.

We've recently had a new kitchen fitted, and we had stainless steel sockets fitted, so I also ordered a fused switch from Screwfix in the same design.

However, when I removed the old isolation switch it has L1, L2 and N, which I'm guessing is for Live, Switched Live and Neutral. The new switch just has Live, Neutral and Earth connections.

Is there any way I can use this switch with the boiler? If not, can anyone point me in the direction of a fused switch, preferably in brushed stainless steel that I can use which has 2 pairs of Live connections and a single Neutral?

Many Thanks in advance...

 

[simond]

Your boiler would have had a 3 pole fan isolaor switch by the sound of it. This probably means you have a fused connection unit somewhere else and the isolator is just that, a local isolator.

In which case the BG man has exceeded his level of expertise, not unusual.

 

[Madrab]

How many cores does the cable from the switch to the boiler have? 3 or 4?

 

[JamesK]

There's 3 cables plus the earth. I can't see a fused connection unit anywhere in the airing cupboard where all the wiring goes back to. The wiring goes directly into the wiring centre for the megaflo.

Here's a couple of (bad) pics...

 

[simond]

Yep, thats a 3 pole fan switch.

Commonly used on newer build to isolate the appliance (boiler) in close proximity. Looking at the cable colours the house will be at least 15 yrs old.

There will be an FCU elsewhere, or some form of fused/MCB protection. This will probably be near the Megaflo wiring centre, you can take the front off and follow the LNE back.

Is that an uninsulated bare end I see? Hmm

 

[Phill Peck]

Bg like to have a fused switch near the boiler because it is there policy to "lock off" the fuse compartment so it can't be accidentally turned back on.
The type of switch u have fitted currently is correct. Afaik there are no fuse triple pole isolation switches.

The one u have isn't compatible . There will be a fused spur in the airing cupboard. It can be turned off and locked off there. He'll just have to go upstairs and do it.

 

[JamesK]

Here's what the airing cupboard looks like... I don't think the large switch is fused either.

 

[Phill Peck]

I would think that red switch is more likely the immersion switch.
There must be one somewhere. Is the house a fairly new build? Maybe ask neighbours if they know where there's is

 

[JamesK]

This is a relatively new installation. Previously that switch controlled all the power to a Boilermate 2000. House is about 12 years old.

 

[Phill Peck]

There wire coming tight to the left of the switch, where does that go?

And the one to the right coming out of the hole in the wall where does that go?

On your main fuse board is the one marked central heating?

 

[JamesK]

Apologies for the delay in responding to those who offered advice on this thread. Just after posting it I went away on holiday for 2 weeks and it completely went out of my head. However, due to another issue with the installation I thought it would be prudent to resurrect it.

I've attached a picture of the cabling and then run from the Megaflo wiring centre as follows:

1 - Nest Heat Link
2 - Pump
3 - Hot Water Zone Valve
4 - Megaflo Cylinder
5 - Bundle of 3 wires. One goes to Thermostat (now powering Nest controller). Remaining 2 goto Kitchen. 1 is used for boiler control the other is unused.
6 - Central Heating Zone Valve
7 - Timer (only used for Central Heating)
8 - Isolation Switch

Cable 9 is no longer used. It previously supplied the Boilermate 2000.

On the fuse board there is a 40A breaker for this circuit.

 

[Agile]

Isn't this switch exactly what it is meant to be, a two pole isolator ?

 

[Dan Robinson]

No. It's a 3 pole isolator.

 

[Dan Robinson]

Isn't this switch exactly what it is meant to be, a two pole isolator ?

What were you saying the other day about people reading posts?

 

[Agile]

Actually the BG man was probably concerned that it did not have a fuse rather than the number of poles.

A three pole switch can also be used as a three, two or one pole switch.

I am not sure that I approve of disconnecting the earth on a boiler.