pipe sizing

[totalshell]

installing a WB 24i junior (25KW) into an older property that has 15mm pipe at present to cooker (adjacent to boiler position) that can barely supply the cooker.
approx distance from meter 25m (inc allowance for 8 elbows)

now it should be easy using the tables etc but i am only confusing myself..
can someone confirm that as the cooker is being removed if i repipe in 22 then that should be adequate ...

 

[gremlin16]

check your essential gas safety manual.

 

[doitall]

Seems a bit short sighted not to allow for a cooker/hob.

 

[totalshell]

rented property so landlord 'removing' his liabilities.
i've looked at the tables and i'm just frying my brains as each ref i look at gives / uses different figures to make the same calculation but i reckon the 25m in 22mm is just about spot on
anyone care to say yeh or nay,,

 

[doitall]

Take the 25kw and divide it by 10.7 that will give you the M³/h, thenjust look up the chart, add 0.5 for each elbow.