Proper flue pipe size 3.5gph oil?

don_200

Being I'm a hvac guy I would have to side with the boiler guy after all he the one that checked draft on a hot and cold chimney I would assume.

Maybe you need to check the size of the liner and see if it can handle the extra load.

Steve Garson_2

Proper flue pipe size 3.5gph oil?

Our oil company just cleaned our Smith Model 19 Series 6 boiler. I asked them to increase the nozzle size from 2.5gph to 3.5gph since it was steaming too slowly.

The tech told us the draft was inadequate and told us to get a chimney liner. Yesterday the chimney pro came and found that the chinmey has a 1-inch liner already. But the liner Tee goes to an 8-inch pipe to the boiler, at which point it goes to a 10-inch opening.

My boiler guy sayes the 8-inch pipe is fine. The chimney guy says we need a 10-inch pipe to the boiler. I don't know who to believe, but every joint of the 8-inch pipe shows black where the sheet metal was crimped, to I tend to believe the chimney guy more.

Should this boiler have a 1-inch pipe to the chimney? The boiler tech has been servicing this building for 20 years.

maine rick

two things that you need to know first
1-max. fireing rate for this boiler-can not over fire
2-what size is the breach at the boiler. if 10in. you have to stay 10 in.
one more, 20 year old or more i would thick about a new boiler

Steve Garson_2

Rick:

The boiler is designed for 6GPH. It was being simmered at 2.5GPH.

The breech has a 10" to 8 inch reducer, which makes me wonder.
So the pipe from the boiler to the chimney (10-feet long) is 8-inch. The oil company tells me that the boiler was shipped years back with the wrong size breech.

The chimney liner is 10-inch, shared with a gas water heater.

The boiler is nine years old.

Leo_15

Smith Install Instructions

Smith Install Instructions for that boiler state the connector from the smoke hood to the chimney be the same size as the opening on the smoke hood. It does list different size smoke hoods but doesn't say which size to use with which number of sections. Looks like a call to Smith is in order. I would assume they sent the right size with a six section boiler but that is just an assumption.

Leo

[Deleted User]

The Smith

19-6 (not 19A) should have come w/ an 8" diameter flue collar.

The 3, 4, & 5 were 7". The 19-7 was 9".

Rob_16

Draft

If you do not have enough draft it is most likly because you do not have enough combustion air coming into the boiler room

Steve Garson_2

> 19-6 (not 19A) should have come w/ an 8" diameter

> flue collar.

>

> The 3, 4, & 5 were 7". The 19-7

> was 9".



Ron:

That's good to know, since it means the present 8-inch pipe is OK.

Thanks,

Steve

Steve Garson_2

Ron:

I guess that means the 8-inch pipe is OK.

Thanks,

Steve