oil boiler sulphur deposits ?

[ar22]

went to a boiler yesterday and found a boiler with a huge build up of sulphur

the owner had the stat set at 80degrees

boiler was running well with no build up of soot

90degree flue so no ingress of water

why so much sulphur build up

cheers

 

[Best]

I assume it was cleaned a year or so ago? Some " service" them without cleaning shell. Some boilers do have a fair bit sulphur even after one year. Did you do combustion test?

 

[SimonG]

Probably running lean, what % CO2 did it have?

 

[ar22]

it had been serviced "a year or so ago" according to the owner

so god knows when really

I only did a combustion test after I serviced it, checked oil pressure and replaced like for like jet

CO2 with no adjustment was 11.7% so pretty good

 

[Best]

A " year or so ago" could mean a lot longer as some don't like you to know boilers been neglected in case u charge more. C02 at near 12% sounds good for modern burner. Set to boiler spec though.