combi - combi changeover

[desrob]

pretty straight forward apart from the gas,,boiler at back of house,meter at front a stair case in the middle of two bedrooms,the current gas pipe goes into concrete floor in 22mm and reappears at the boiler in 15mm,any band a combis that are suitable for 15mm supply,if i take the gas pressusre at pressent combi and i'm getting 18mbar + can i assume.no easy way of getting new gas line in or is there.

 

[Roger Welton]

Whats the present combi's heat input, and the proposed replacements?

 

[AWheating]

whats the WP/drop from meter to boiler?

 

[desrob]

whats the WP/drop from meter to boiler?

sorry i don.t know,what you thinking.?if in range and current boiler has a higher rated heat input than the new one.....? could be ok,,,?

 

[migoplumber]

like mr awheating has said, the first thing you need to know is the drop in working pressure on the meter. even if you have a boiler that will sit on your 15mm pipe and you install it, if the drop is too much you fail on gas regs.

 

[AWheating]

if the pressures are ok then i would think of trying the existing pipework, if when fitted its not good then new pipework needed. main worry could be effects on other appliances if undersized.

 

[desrob]

if the pressures are ok then i would think of trying the existing pipework, if when fitted its not good then new pipework needed. main worry could be effects on other appliances if undersized.

it's the only gas appliance in property

 

[wigan_plumber]

ideal logics can be fitted on 15mm aslong as your working pressures are ok.

 

[desrob]

ideal logics can be fitted on 15mm aslong as your working pressures are ok.

the pressure at meter was 16mbar so i did not bother checking inlet at boiler,i'm waiting for provider to come and put me a new regulator on.

 

[AWheating]

having a 15mm isolation valve does not make 15mm pipe suitable, nor can boiler instructions decide on pipe size. You will only be able to confirm it with calculation or tests.

 

[desrob]

tested and 19 mbar at boiler only gas appliance in property