burner pressure and gas rate dont tally up

[princegoose]

Hi, was servicing my brothers old boiler the other day, after boiler fires up theres a slight smell of gas then burner sounds pretty erratic. Checked burner preuuser which was a bit over maximum. adjusted it to just above minimum and seemed to work and sound a lot better at startup, however the gas rate was more than 5% (and more than 10%) below what it shuld have been for the burner pressure I set. Any one know any reasons for this?

 

[markinaark]

had you got appliance on full for 10 mins, check pipe sizing to appliance, or maybe injector to blocked or to small,

 

[fuzzy]

yeh as above, blocked injector, pipe sizing check

try the stats again after running for a bit