My first cylinder install with boiler

[ShaunCorbs]

THATS why benchmarks is asking for it I guess if you are in a hard water area above 200 you require one that’s what benchmark says . can’t remember 100% but you definitely have to fit one

Not true, scale filter isn't required on an unvented

Now if it is over 200ppm then you require a softening

 

[Last Plumber]

Lol you know what.. I was really excited to do it as it was my first fresh system and the wiring was no issue.. wired it up, switched it on and everything worked!! Happy days! Had to check the cylinder stat wiring as I’ve never done that before but yeah.. probably the easiest part of the whole job.. who’d have thought eh

Apart from the bits and bobs others have mentioned it looks good.

The only wee thing I would add is that the immersion would be best on a 20 Amp Switch as opposed to a 13 Amp switched fused spur.

 

[jaydebruyne]

Apart from the bits and bobs others have mentioned it looks good.

The only wee thing I would add is that the immersion would be best on a 20 Amp Switch as opposed to a 13 Amp switched fused spur.

Cheers last!! An electrician wired up the immersion lol immersion’s don’t draw more than 13 amps, why would you need a 20 amp switch?

 

[Best]

Cheers last!! An electrician wired up the immersion lol immersion’s don’t draw more than 13 amps, why would you need a 20 amp switch?

I actually had the same point about immersion switches on this forum and it was clarified by some of the more electrical experienced guys, maybe Shaun.
The immersion works on the limit of 13amp, so a spur switch that is 13amp might burn out at the internal switches (for neutral and live) or at the 13 amp fuse.
It depends on if the supply is 240 volt or if it is lower, because the amps raise if voltage lowers I think.
Normally you will have 15 or 16 amp fuse or the mcb fuses at electric consumer unit and then any switches on that for the immersion should be 20 amp 2 pole switches.

 

[jaydebruyne]

I actually had the same point about immersion switches on this forum and it was clarified by some of the more electrical experienced guys, maybe Shaun.
The immersion works on the limit of 13amp, so a spur switch that is 13amp might burn out at the internal switches (for neutral and live) or at the fuse.
It depends on if the supply is 240 volt or if it is lower, because the amps raise if voltage lowers I think.
Normally you will have 15 or 16 amp fuse or the mcb fuses at electric consumer unit and then any switches on that for the immersion should be 20 amp 2 pole switches.

Makes sense.. thanks for clarifying Best

 

[ShaunCorbs]

Correct best but in certain circumstances the immersion can be taken off the ring main and doesn't need its own circuit

 

[Best]

Sparks use 13 amp fused spurs on everything and leave the 13 amp fuse in them on heating wiring etc.
Idiots! Never trust a Spark.

 

[Best]

Correct best but in certain circumstances the immersion can be taken off the ring main and doesn't need its own circuit

I knew you would add that!

 

[jaydebruyne]

Correct best but in certain circumstances the immersion can be taken off the ring main and doesn't need its own circuit

I went to service a megaflo about a month ago and had Main and boost immersion wired together using a single cable into a 16amp circuit breaker.. disconnected the boost immediately!!!

 

[ShaunCorbs]

I knew you would add that!

It's weird as a stnd immersion can pull around 12-13 amps

but to trip a fuse you would need to be pulling around 26 amps and on a mcb closer to 20 amps scary lol

 

[ShaunCorbs]

I went to service a megaflo about a month ago and had Main and boost immersion wired together using a single cable into a 16amp circuit breaker.. disconnected the boost immediately!!!

Both 3kw immersion or a 1.5kw and 3kw ?

 

[ShaunCorbs]

Sparks use 13 amp fused spurs on everything and leave the 13 amp fuse in them on heating wiring etc.
Idiots! Never trust a Spark.

Most can't even wire an s plan it's getting less and less that are able to do it

 

[Best]

On the subject of 13amp spur switch on immersion’s being totally wrong, - my house had same in airing cupboard as the final isolator for immersion. Had been working perfectly for over 40 years of daily use, until I replaced it with a 20 amp switch with neon.
But the old MK switch was probably better quality than the new switches

 

[ShaunCorbs]

On the subject of 13amp spur switch on immersion’s being totally wrong, - my house had same in airing cupboard as the final isolator for immersion. Had been working perfectly for over 40 years of daily use, until I replaced it with a 20 amp switch with neon.
But the old MK switch was probably better quality than the new switches

And do you realise standard 13amp fcu will be rated at around 18amps for safety (able to take 13amps easy)

 

[jaydebruyne]

Both 3kw immersion or a 1.5kw and 3kw ?

2 x 3kw elements

 

[ShaunCorbs]

2 x 3kw elements

did it blow the fuse ?

 

[jaydebruyne]

did it blow the fuse ?

Lol I were’nt gonna Flick the switch

 

[ShaunCorbs]

Lol I were’nt gonna Flick the switch

Chicken was it warm ?

 

[jaydebruyne]

Chicken was it warm ?

Funnily enough the cylinder was heated by the boiler so I didn’t need to test them both.. just disconnected the boost and tested the main.

 

[Harvest Fields]

Most can't even wire an s plan it's getting less and less that are able to do it

Probably shouldn’t say this but I do my own wiring.

 

[ShaunCorbs]

Probably shouldn’t say this but I do my own wiring.

So do I easier in the long run

 

[jaydebruyne]

Probably shouldn’t say this but I do my own wiring.

Same here..

 

[Best]

And do you realise standard 13amp fcu will be rated at around 18amps for safety (able to take 13amps easy)

Yes, a friend of mine is an electrical/electronics guy and told me the fuses are rated much higher.
Not sure what extra % of amps he told me, but think he said they could take surges for short periods.
I am still trying to learn the more technical bits of electrics.

 

[ShaunCorbs]

Yes, a friend of mine is an electrical/electronics guy and told me the fuses are rated much higher.
Not sure what extra % of amps he told me, but think he said they could take surges for short periods.
I am still trying to learn the more technical bits of electrics.

About 11/2 times rated amps for an hour

 

[Last Plumber]

I actually had the same point about immersion switches on this forum and it was clarified by some of the more electrical experienced guys, maybe Shaun.
The immersion works on the limit of 13amp, so a spur switch that is 13amp might burn out at the internal switches (for neutral and live) or at the 13 amp fuse.
It depends on if the supply is 240 volt or if it is lower, because the amps raise if voltage lowers I think.
Normally you will have 15 or 16 amp fuse or the mcb fuses at electric consumer unit and then any switches on that for the immersion should be 20 amp 2 pole switches.

Twas I, many moons ago !

 

[Last Plumber]

Cheers last!! An electrician wired up the immersion lol immersion’s don’t draw more than 13 amps, why would you need a 20 amp switch?

As Shaun and Best have already said, If the Volts drop the Amps rise.
3000W/240V=12.5A
3000W/230V=13.04A and so on.
I have come across many melted switches in the past, mainly due to circumstances. e.g. Customer uses immersion in summer rather than Boiler, therefore it's on a lot of the time.
In the cases I have seen it has been the fuse running hot that caused the issue. A fuse will not blow dead on its rating!
If the Voltage is good and the immersion is used as a back up every now and then, there is not normally a problem but it is worth knowing.

 

[Best]

Twas I, many moons ago !

Apologies Mr Last!
Without trying to find the thread, I do think I recall it was indeed you who had informed me about it being wrong for 13amp spurs to a 3kw immersion.
Why are you not a Trusted Advisor on here yet, come to think of it?

 

[Last Plumber]

Apologies Mr Last!
Without trying to find the thread, I do think I recall it was indeed you who had informed me about it being wrong for 13amp spurs to a 3kw immersion.
Why are you not a Trusted Advisor on here yet, come to think of it?

I must not be worthy! lol

 

[Harvest Fields]

I must not be worthy! lol

I’ve got one and I’m useless most of the time I’m sure it will not be long before they realise you are good

 

[Best]

I must not be worthy! lol

Definitely well worthy of it mate and long ago!

 

[mikeygas]

Hey Jay,

Tidy looking install, you’ve done really well to cram all that lot together in there.

Not looking for faults, but on my phone it looks like you have tee’d in the blow-off from the heating system at expansion vessel with the expansion relief blow-off at the inlet group?

 

[ShaunCorbs]

Hey Jay,

Tidy looking install, you’ve done really well to cram all that lot together in there.

Not looking for faults, but on my phone it looks like you have tee’d in the blow-off from the heating system at expansion vessel with the expansion relief blow-off at the inlet group?

And ?

 

[mikeygas]

Didn’t know regs had changed to allow combining of potable and heating system discharge?

 

[ShaunCorbs]

Didn’t know regs had changed to allow combining of potable and heating system discharge?

It's always been ok (last 5-10 years)

 

[jaydebruyne]

Hey Jay,

Tidy looking install, you’ve done really well to cram all that lot together in there.

Not looking for faults, but on my phone it looks like you have tee’d in the blow-off from the heating system at expansion vessel with the expansion relief blow-off at the inlet group?

Hey Mikeygas, I have yes. I wasn’t aware of any regs that disallowed this..

 

[Harvest Fields]

Hey Mikeygas, I have yes. I wasn’t aware of any regs that disallowed this..

Don’t think there is mate. It is allowed in all the instructions I have seen.

 

[mikeygas]

Okay guys thanks for the swift response i’ll Check back up as I was led to believe it contraves water regs as it could lead to cross contamination of potable water supply with heating water discharge.

(Hypothetical , worst case scenario, I know Lol) I.e blockage after where both pipes are tee’d in, heating system then discharges at 3 bar, then passing expansion relief valve at cold water inlet group could lead to backflow into cold water supply.

 

[mikeygas]

Okay guys thanks for the swift response i’ll Check back up as I was led to believe it contraves water regs as it could lead to cross contamination of potable water supply with heating water discharge.

(Hypothetical , worst case scenario, I know Lol) I.e blockage after where both pipes are tee’d in, heating system then discharges at 3 bar, then passing expansion relief valve at cold water inlet group could lead to backflow into cold water supply.

 

[mikeygas]

Just seen your reply Harvest!

Can you point me in the right direction to look, just interested!

Thanks.

 

[ShaunCorbs]

Would Sod out of the tundish first

 

[Harvest Fields]

Not off the top of my head mate. But mould start with building regs g3.

Leave it with me and I will see what I can find

 

[mikeygas]

Read me hypothetical post Shaun

I said after where there tee’d, thus a blockage before the D1, not trying to play Devils advocate too much!

 

[mikeygas]

Cheers harvest, will check back in my last study book.

Last renewed my ticket in 2015/2016 so it had changed to include vented hot water as well.

 

[ShaunCorbs]

Read me hypothetical post Shaun

I said after where there tee’d, thus a blockage before the D1, not trying to play Devils advocate too much!

What would block it

I could understand d2 blocking due to moss / other things also if d1 is blocked you have bigger issues than back flow you have a bomb

 

[mikeygas]

That’s why I said Hypothetical, worst case etc

Imagine if it was blocked, can you see what i’m trying to say about backflow, x-contamination etc?

Remember the water regs about disconnecting filling loops after topping up systems to prevent backflow.

Which i’m sure we all disconnect

 

[ShaunCorbs]

That’s why I said Hypothetical, worst case etc

Imagine if it was blocked, can you see what i’m trying to say about backflow, x-contamination etc?

Remember the water regs about disconnecting filling loops after topping up systems to prevent backflow.

Which i’m sure we all disconnect

Don't think it would matter when half your house blows up (then some heating water would get into the mains anyway)

 

[mikeygas]

Sorry I can’t explain it better to you Shaun.

 

[jaydebruyne]

Okay guys thanks for the swift response i’ll Check back up as I was led to believe it contraves water regs as it could lead to cross contamination of potable water supply with heating water discharge.

(Hypothetical , worst case scenario, I know Lol) I.e blockage after where both pipes are tee’d in, heating system then discharges at 3 bar, then passing expansion relief valve at cold water inlet group could lead to backflow into cold water supply.

The inlet valve has a NRV inside so no chance of cross contamination.. also there is an air gap via the tundish so again, not much chance of backflow.. also the likelihood of a blockage is pretty much slim to never..

 

[Best]

The D2 pipe will block easily at end if something gathered near the ground outlet, or if a gulley blocked on a stupid regulations method of the end of the pipe terminating below the gulley grid was used. That just air locks the D2 and water will come out of tundish

 

[mikeygas]

Check valves do fail Jay and let by.

I know that the set-up you have done will be fine, but i was just querying whether it was done to standard, as when I did my first G3 it was a no-no.

As said I will look up info or speak to CIPHE and post back.

Happy to be proved wrong

 

[mikeygas]

Hi Guys,

Update for anyone that is still interested, or has the will to live!

I’ve spoke to one of the tech advisers at the CIPHE and he’s said G3 regs only cover the potable water discharges into D1 & D2, and not the discharges from central heating. Therefore you shouldn’t combine them.

I then asked him where it says in any doc or reg that you cannot do it, and he basically said if an incident happened (I.e flood from tundish causing water damage due to all discharges blowing off at same time or others etc) and it went to court then the expert witness’s would pull out the G3 discharge drawing (the one that’s in all u/v cylinder install instructions) and then basically say show me on that drawing where it shows that the central heating blow-off is allowed to be connected into the D1/D2 pipework.

As we all know the drawing shows no such thing.

Hope this helps anyone out in the future.

Cheers.