Advice for boiler option for 15 mm pipe gas supply into the flat

[LondonNL]

Need to replace a 20+ year combi boiler (doesn't work), it is in a 65 sq m (2 bedroom 1 bath/shower) flat on a second floor of a Victorian house in central London. The only other appliance that uses gas is a cooker. It is likely that the 15 mm pipe is all the way from the gas meter that is in the basement outside. It may not be an option to run 22mm pipe all the way up inside the building through other people's flats etc etc and not allowed outside.

- Is there an option to install a lower efficiency new boiler that gas work on gas supply through a 15 mm pipe? Is it correct that while suboptimal from efficiency point of view it is likely to work fine/be safe etc, and while manufacturer's warranty will be affected I should expect the bolier as it is new to work well for a number of year?

- If this is possible what boiler model should I look for [BG engineer mentioned that Vallient Ecoteck Pro 24 can work reasonably well off 15 mm]

- would it help if I replace a cooker with an electric one ?

- is there a way to check whether there is somewhere a 22 m pipe in the flat without removing floors etc? There is definitely a 15 mm coming to the cooker.

Your advise is much appreciated! Thank you in advance.

 

[cjg]

( theres got to be 22mm some where there) you can not run a combi off 15mm that distance it would starve
of gas, you will have to have a dig around find a good supply and 22 to boiler. then check you have enough
gas flow.

 

[Riley]

What does your gas safe engineer say??

 

[LondonNL]

Thank you, we have found out that there is a 22 mm pipe going from the meter in the basement so I suppose good news. How do I find out where it comes into the flat without doing a major disruption?

 

[Riley]

Guess work unless you find the pipe

 

[LondonNL]

Guess work unless you find the pipe

apologies, could you pls elaborate?

 

[Riley]

I was saying that where the pipe comes into the flat is guess work without finding the pipe. It could be anywhere and also guesswork where it reduces to 15mm

 

[LondonNL]

I was saying that where the pipe comes into the flat is guess work without finding the pipe. It could be anywhere and also guesswork where it reduces to 15mm

understood, thank you

 

[WC1]

Your installer should be able to make an educated guess and probably need to pull up some floorboards to find it.

 

[LondonNL]

one question: if the connection is 22mm to the flat then a section of 15 mm and then 22 mm to the boiler, would that work? one engineer suggested that this is possible and wont affect materially gas pressure/boiler performance.

 

[steadyon]

Have a look at the old, non-functioning boiler. One of the pipes underneath it will be the gas supply pipe. It may already be 22 mm. If not, follow it back to the floor and see if it is joined to a 22 mm pipe.
Far from guaranteed but it's most likely that the supply to the flat is 22 mm, and the cooker has been tee'd off in 15 mm.

 

[king of pipes]

Gas regulations state there should be a fire proof ECV isolation valve in a accessible position where the gas enters the property ie (your flat ) for emergency use, with a test point down stream of the valve and labelled if there isn't one then the gas supply is not fitted to the gas regulations ? If you should have a leak then there's not quick access to a isolation valve? the consequences could be dire.
Find where the gas enters your flat and go from there if it's 22mm it maybe enough 15 mm then it needs a upgrade . Regards kop

 

[cjg]

as above but you should aslo turn off at the meter in case the leak is before the ecv in the flat, you should have acess to the main meter at all times
--------------------

 

[Knappers]

I think there's an exception to having a valve as it enters flat, something like having own clearly identified meter box and may be other requirements but that being said it should ideally have an aecv in flat too.

 

[Lou]

Please seek advice from a Gas Safe Registered plumber

 

[cjg]

you should have acess to the main meter at all times