Put combi boiler in outside loo or bathroom airing cupboard?

[paulwatford]

Wow, thanks for all brilliant advice from bengasman, glasgowgas, agile, dextrous, namsag etc. Really really useful. I'm going with the airing cupboard even though it was not my first choice. I can't ignore all that good advice from people who know what they are talking about. What I really wanted was a boiler in just the same place as my 38 year old ideal concord which has happily flued up the chimney since 1971, but alas I am told you can't flue up the chimney anymore.
Will I really need an upgrade to 28mm gas supply pipe? I've measured the old pipe and its 22mm, and it goes halfway to where I want it to go already. Even the piece of concertina like bendy pipe that the gas board fitted that runs from the mains TO the gas meter is only 25mm. Would the 22mm supply do if I downsized to a Worcester Bosch 30CDi (I was going for a 37CDi) or would I still need 28mm pipe?
The water flow from my tap was measured at 23 litres per minute. Many thanks Paulwatford

 

[dextrous]

Will I really need an upgrade to 28mm gas supply pipe? I've measured the old pipe and its 22mm, and it goes halfway to where I want it to go already. Even the piece of concertina like bendy pipe that the gas board fitted that runs from the mains TO the gas meter is only 25mm. Would the 22mm supply do if I downsized to a Worcester Bosch 30CDi (I was going for a 37CDi) or would I still need 28mm pipe?
The water flow from my tap was measured at 23 litres per minute. Many thanks Paulwatford

Your gas fitter will know best - it's to do with the pipe length, number of bends, number of other gas appliances, required gas flow etc, etc. He will do the necessary calculations (or experience will tell him). If you downsize your boiler, then the flow rate of hot water coming from it will fall also, which seems a wasted opportunity which you may come to regret for the sake of saving a bit of cash now.

 

[glasgowgas]

second Dextrous advice.

ps Vokera do a range of flues that run up your chimney, if that helps with an easier boiler location

 

[bengasman]

A vokera or a wb cdi, ......... let me think.

 

[glasgowgas]

honestly ben g, we have fitted nearly 1600 Unica`s with, off the top of my head, 19 in warranty failures.

only giving the OP a wee selection choice for preffered flueing!!!

 

[bengasman]

honestly ben g, we have fitted nearly 1600 Unica`s with, off the top of my head, 19 in warranty failures.

Just over 1%, that is not as bad as I though to be honest.
Unless the warrantee period has been reduced to 3 hours.

 

[glasgowgas]

 

[paulwatford]

Thank you once again to all of you for being so helpful. What a great lot you are. I'm going with a worcester bosch in the airing cupboard (this is beginning to sound a bit like Cluedo!) and I'll take fitters advice as to whether I need to upgrade to 28mm pipe. Will have new "valves" at both ends of radiators as recommended and all the flushing and magnaclean as recommended by you. Will just have to go back to do some part time worrk to pay for it all.
Do you think the 38 year old radiators will be OK? They've never given a moment of trouble so far with no signs of rust on surface. Paulwatford

 

[namsag]

I have still got a couple of 37 year old ones ,
In all honesty you can check all around the and they will look Ok and 99.9 times out of hundred they are , but occasionally when system flushed and then under pressure weakness will show and rad will leak .
But have connected onto thousands of rads and had less than a hand full split

 

[Razor900]

A vertical flue will be a lot more than a horizontal one and particularly if the full H&S requirements are met which at BG mean giving it to a subby normally!

Tony

Wish I was brave enough to charge £30/m for gaspipe, does that reflect the extra trouble of moving it about on the underground?
And the bit between the main and the meter is at a higher pressure then after the meter thats why it will flow more gas