Boiler Switch

[Jamesa2487]

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

 

[timhoward]

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]

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]

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]

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]

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?

 

[nicebutdim]

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

That text will be very easy to remove, without any detrimental impact to the switch's cosmetic appearance - such is the nature of printed text on BG decorative accessories.

 

[Jamesa2487]

That text will be very easy to remove, without any detrimental impact to the switch's cosmetic appearance - such is the nature of printed text on BG decorative accessories.

I'll give it a go. It was more making sure I have the correct switch. Any tips for getting the lettering off

 

[nicebutdim]

I'll give it a go. It was more making sure I have the correct switch. Any tips for getting the lettering off

We have some BG brushed accessories as they were the only brand that offered grey inserts, rather than the usual option of black or white.

Much better quality than I had expected, but lettering started to disappear from cooker switch and that very same 3 pole isolator (used for the very same purpose) about the third time my other half wiped them with a cloth. I quickly finished the job with a thumb nail.

 

[timhoward]

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

We don't have that information. If so, I agree absolutely no problem. But the boiler spur might equally be on a 16A radial or on the RFC.

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?

Sorry If I added confusion. The potential issue is just how much current the switch is designed to handle. Not so much about whether the boiler will overload it, more whether the regs allows a 10amp switch on a supply that is potentially fused higher.
Do you know which circuit breaker or Fuse isolates the boiler at your consumer unit? Does it have it's own breaker or Fuse or is it part of a plug sockets circuit?

 

[Jamesa2487]

We don't have that information. If so, I agree absolutely no problem. But the boiler spur might equally be on a 16A radial or on the RFC.

Sorry If I added confusion. The potential issue is just how much current the switch is designed to handle. Not so much about whether the boiler will overload it, more whether the regs allows a 10amp switch on a supply that is potentially fused higher.
Do you know which circuit breaker or Fuse isolates the boiler at your consumer unit? Does it have it's own breaker or Fuse or is it part of a plug sockets circuit?m

We don't have that information. If so, I agree absolutely no problem. But the boiler spur might equally be on a 16A radial or on the RFC.

Sorry If I added confusion. The potential issue is just how much current the switch is designed to handle. Not so much about whether the boiler will overload it, more whether the regs allows a 10amp switch on a supply that is potentially fused higher.
Do you know which circuit breaker or Fuse isolates the boiler at your consumer unit? Does it have it's own breaker or Fuse or is it part of a plug sockets circuit?

It has one on the circuit breaker picture attached

 

[timhoward]

My view having read up a little on this is that it's fine to use that switch. Apologies for distracting the thread by querying this. I like to know why things that feel like they ought to be allowed are actually allowed....

Reg 537.3.2.2 "When a switch is provided for this purpose [isolation for maintenance] is shall be capable of cutting off the full load current of the relevant part of the installation."

The full load-current would be the boiler current draw - control circuity, pump and fan. Should be nowhere near 10 amps.