Boiler Switch

Jamesa2487 · Apr 22, 2021

Hi

We are having a new kitchen installed and have changed ll the sockets / switches to a stainless steel (Like below)

BG Screwless Flat Plate Brushed Stainless Steel 13A Spur Unit

A stylish fused connection unit from BG Electrical, featuring a contemporary slimline design and an attractive brushed steel finish to enhance any modern interior.This FCU has a single switch and provides an outlet from the mains containing the fuse – perfect for spur circuits and hard-wired...

www.toolstation.com

There is a boiler switch below the boiler which i cant seem to find a switch for. Can i just use a fused spur? any advise would be great. I have found 3 pole switches but they all say "fan isolation" on them

littlespark · Apr 22, 2021

You might need to get an electrician to trace what all the cores are doing.
Normally there is just a switch fuse that isolated the entire heating system.

I don’t think I’ve ever seen a 3 pole isolator on boiler circuits??

snowhead · Apr 22, 2021

I suspect the 3 pole switch has been used to replace a programmer that would have originally been there.
The simplest fix is to fit another 3 pole fan isolator.

If the adjacent spur is the sole supply to the heating system (can't see any sideways interconnection) or if there is a single spur supplying the heating elsewhere, then the 3 pole could probably be eliminated by using connectors then just have a blank fitted over, checking would be required.

Jamesa2487 · Apr 22, 2021

T

snowhead said:
I suspect the 3 pole switch has been used to replace a programmer that would have originally been there.
The simplest fix is to fit another 3 pole fan isolator.

If the adjacent spur is the sole supply to the heating system then the 3 pole could probably be eliminated by using connectors then just have a blank fitted over, checking would be required.

Hi

So that is a 3 pole switch? ill just buy one that says Fan its thats the case

Mike Johnson · Apr 22, 2021

Tip: keep the photo to let you trace the cable/terminal connections.

telectrix · Apr 22, 2021

if it's a 3 pole switch, fit a fan switch and re-label it with brother.

littlespark · Apr 22, 2021

Jamesa2487 said:
T

Hi

So that is a 3 pole switch? ill just buy one that says Fan its thats the case

You might be able to find one that has no writing on it.

As suggested above though... if the 3 pole isolator isnt actually doing anything... (do you turn it on and off frequently? is the whole heating system also isolated elsewhere?) then you could joint through each switch and cover with a blank plate in the decoration you need...

Advise: If your changing these to metal, then you might need to earth the plate

Jamesa2487 · Apr 22, 2021

littlespark said:
You might be able to find one that has no writing on it.

As suggested above though... if the 3 pole isolator isnt actually doing anything... (do you turn it on and off frequently? is the whole heating system also isolated elsewhere?) then you could joint through each switch and cover with a blank plate in the decoration you need...

Advise: If your changing these to metal, then you might need to earth the plate

I've purchased the below. Will this be ok do you think ?

BG Screwless Flat Plate Brushed S/S 3 Pole Fan Isolator

A stylish fan isolator switch from BG Electrical, featuring a contemporary slimline design and an attractive brushed steel finish with matching rocker switch.This triple pole switch provides a safe and simple method of isolating mechanical fan units, and features a wide rocker for easy...

www.toolstation.com

Jamesa2487 · Apr 22, 2021

I've purchased the below. Will this be ok do you think ?

BG Screwless Flat Plate Brushed S/S 3 Pole Fan Isolator

A stylish fan isolator switch from BG Electrical, featuring a contemporary slimline design and an attractive brushed steel finish with matching rocker switch.This triple pole switch provides a safe and simple method of isolating mechanical fan units, and features a wide rocker for easy...

www.toolstation.com

telectrix · Apr 22, 2021

Jamesa2487 said:
I've purchased the below. Will this be ok do you think ?

BG Screwless Flat Plate Brushed S/S 3 Pole Fan Isolator

A stylish fan isolator switch from BG Electrical, featuring a contemporary slimline design and an attractive brushed steel finish with matching rocker switch.This triple pole switch provides a safe and simple method of isolating mechanical fan units, and features a wide rocker for easy...

www.toolstation.com

need a perfect skim on the wall.perfectly flat or your switch will keep falling off. flatplate.... spawn of the devil.

Jamesa2487 · Apr 22, 2021

telectrix said:
need a perfect skim on the wall.perfectly flat or your switch will keep falling off. flatplate.... spawn of the devil.

Hi

Yes in terms of the flat face i get that.

In regards to if its the correct type of switch i mean?

timhoward · Apr 22, 2021

Provided it's wired to simply call for heat/water or not, which is most likely, then that 10A switch is fine - most heating programmers only have contacts rated at 3amps anyway.

It would be interested to know if there's a fused spur elsewhere for the boiler, and whether it has a wireless programmer/time clock as many do these days. Do you ever use that switch?

goasis · Apr 22, 2021

It will be to isolate the boiler locally, assume the heating controls and wiring Centre are elsewhere with their own isolator. So there will be a permanent live, neutral and a switched live for the boiler. That 3 pole isolator most likely is to disconect those 3.

EDIT although looking at the photo again, I'm not so sure.....

timhoward · Apr 22, 2021

I'm not 100% sure either. I'm not sure any of us can be without a closer look at what's going on there.
But In a sense it only matters either way if the switch rating matters.

Permit me to ask a silly question which I accept I should know the answer to:
Are you allowed to stick a 10amp rated switch on a (probably) 13A fused spur with a known load on the basis that it will never draw anything approaching 10amps most of the time (fan and pump really) and the switch would only have to survive long enough in fault conditions to blow the upstream fuse. A similar principle to 433.1.1. But I can't recall ever noting this being allowed. I also don't have BBB here to consult and my default position would be "no".
Anyone?!

(I also note that triple pole 20 amp switches marked boiler are practically non existent, though there are double pole 20 amp ones out there. )

DPG · Apr 22, 2021

timhoward said:
I'm not 100% sure either. I'm not sure any of us can be without a closer look at what's going on there.
But In a sense it only matters either way if the switch rating matters.

Permit me to ask a silly question which I accept I should know the answer to:
Are you allowed to stick a 10amp rated switch on a (probably) 13A fused spur with a known load on the basis that it will never draw anything approaching 10amps most of the time (fan and pump really) and the switch would only have to survive long enough in fault conditions to blow the upstream fuse. A similar principle to 433.1.1. But I can't recall ever noting this being allowed. I also don't have BBB here to consult and my default position would be "no".
Anyone?!

(I also note that triple pole 20 amp switches marked boiler are practically non existent, though there are double pole 20 amp ones out there. )

Don't forget you use 20 Amp switches in kitchens for example. What's the OCPD rating in that case?

timhoward · Apr 22, 2021

DPG said:
Don't forget you use 20 Amp switches in kitchens for example. What's the OCPD rating in that case?

That actually doesn't feel the same...
20amp switch then 13A fuse (either in plug or FCU) then appliance. Current through switch is limited to below it's rating.
I think this would potentially be 13amp fuse, 10 amp switch in middle, then appliance? Current through switch not limited to below it's rating?

DPG · Apr 22, 2021

timhoward said:
That actually doesn't feel the same...
20amp switch then 13A fuse (either in plug or FCU) then appliance. Current through switch is limited to below it's rating.
I think this would potentially be 13amp fuse, 10 amp switch in middle, then appliance? Current through switch not limited to below it's rating?

True yes. I'll have another think!

Jamesa2487 · Apr 22, 2021

timhoward said:
Provided it's wired to simply call for heat/water or not, which is most likely, then that 10A switch is fine - most heating programmers only have contacts rated at 3amps anyway.

It would be interested to know if there's a fused spur elsewhere for the boiler, and whether it has a wireless programmer/time clock as many do these days. Do you ever use that switch?

Hi

No never really use the switch. When we moved in it had a programmer by the boiler and a analogue dial by the front door.

We have since installed Hive. Bit annoying as I've had to get a switch that says "Fan Isolator"

goasis · Apr 22, 2021

timhoward said:
I'm not 100% sure either. I'm not sure any of us can be without a closer look at what's going on there.
But In a sense it only matters either way if the switch rating matters.

Permit me to ask a silly question which I accept I should know the answer to:
Are you allowed to stick a 10amp rated switch on a (probably) 13A fused spur with a known load on the basis that it will never draw anything approaching 10amps most of the time (fan and pump really) and the switch would only have to survive long enough in fault conditions to blow the upstream fuse. A similar principle to 433.1.1. But I can't recall ever noting this being allowed. I also don't have BBB here to consult and my default position would be "no".
Anyone?!

(I also note that triple pole 20 amp switches marked boiler are practically non existent, though there are double pole 20 amp ones out there. )

But what rating is your OCPD at the board? 6A for heating?

Jamesa2487 · Apr 22, 2021

Well now I'm lost lol

I have purchased a 3 pole fan 10amp switch.

It seems to have the same outputs L1 L2 etc...

Next to the boiler is the Hive box which I'm sure is wired into this switch then up to the boiler. I could be wrong.

Would any more photos help?