Oil boiler grey smoke

[diesel_ltd]

Hi was just a an oil boiler with RDB burner it has some grey smoke coming from the flue, co 9 ppm co2 11.5 pump 8 bar the boiler has Been off for a few weeks just wondering if anyone I come across this, I'm thinking its cus it hasn't been run in a while and the poc's are clean ?

 

[heliotrope]

Is it smoke or vapor? If not used for a long period then things can get
pretty damp inside the flue and boiler.

The numbers look good to me.

Is it still issuing grey stuff after boiler firing for half an hour or so?

 

[diesel_ltd]

We have had heavy rain today which was soaking the flue but not sure if it was getting down the flue, it was in a friends house so I told him to run it for a few hours and let me know how he gets on so I'll not know until tomorrow if it still doing it, he just had a fill of oil today also I checked his oil filter which was clean

 

[peteheat]

Grey would suggest heavy plume maybe the boiler got damp.

 

[bright spark]

Could be dampness alright. Also did you check the flue gas temp. Presume its not a condensing boiler. If the nozzles not the right size for the boiler yer gonna get condensation forming in the flue causing grey/white smoke to appear at the flue outlet.

 

[Roger Welton]

I hate cleaning out boilers when they have been off for ages, all sticky and nasty