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My first cylinder install with boiler

View the thread, titled "My first cylinder install with boiler" which is posted in Boiler Advice Forum on UK Plumbers Forums.

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

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