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.