New Combi Boiler with 15mm gas supply

katy123

I'm a little concerned, I have always been advised that for a combi you need a 22mm gas supply. I've just had a worcester combi installed and the gas registered fitter located the 22mm in the ground but from the wall up it is 15mm. Therefore there is approx 1.5 meters where the gas supply is connected with a 15mm pipe. He assured me this is ok and proved it with his handheld meter readed showing co2 output of 8.9 which is as advised by the boiler manual. Is this ok? Thanks.

muckybutt

What make and model ?

All the Greenstar range specify 22mm

ariba10

Our's is the same and have had no problems in the six years it has been in.

daveyjp

The installation manuals will give the size of gas pipe required.

southcoastrgi

it depends on the working gas pressure at the meter & boiler (which he should have tested) as more than 1mb difference means it's AR & gets shut off, plus this is tested with all the other gas appliances running, but yes it is normally 22mm

southcoastrgi

ariba10 wrote: »

Our's is the same and have had no problems in the six years it has been in.

as the OP hasn't said the model & output of their boiler your point isn't relevent, plus unless your boiler has been tested in accordence with my post above there is no guarentee that yours is correct.

katy123

wow, thanks for all the prompt replies...the model is worcester greenstar 28i combination boiler

C_Mababejive

Its all about flow rate and pressure loss. In some circumstances you might need 35mm copper ! Pretty rare I'll grant you !

southcoastrgi

if it's the 28i junior then the gas connection to the boiler is 22mm & the connected gas supply pipe is not allowed to be any smaller than this, plus the co2 readings should be 9.8 on max & 9.2 on min so your installer not only has connected the incorrect gas supply pipe size but he hasn't commisioned it correctly either

katy123

apologies, after 30 mins of running (approx) he showed me the reading and it read 9.7 or 9.9 i remembered it was 0.1 higher or lower than the "co2 level at max. rated heat output (after 30 minutes)"

katy123

if he has installed it incorrectly, what do I do? Contact gas safe? The heating and hot water seems to work fine. Poster Ariba10 also has this set up without any probs.

i haven't paid the fitter, he fitter it on friday

there is 5 years warranty on the boiler...I guess my main concern is the safety or would it just shut itself off