Flue liner size for boiler?

[NH Homesteader]

I have to line my old chimney flue before installing a new boiler. I plan to have an stainless liner installed. Flue dimensions are roughly 10 3/4" x 12".

The boiler will most likely be a Buderus G215 which has a 6" vent connection. The flue length is 30', and will not be shared with anything else.

2 questions:

What diameter liner for this boiler and a 30' flue?

Any recommendations against a standard stainless steel liner (like Z Flex)?

Regards, NH Homesteader

[flamefix]

I have to line my old chimney flue before installing a new boiler. I plan to have an stainless liner installed. Flue dimensions are roughly 10 3/4" x 12".

The boiler will most likely be a Buderus G215 which has a 6" vent connection. The flue length is 30', and will not be shared with anything else.

2 questions:

What diameter liner for this boiler and a 30' flue?

Any recommendations against a standard stainless steel liner (like Z Flex)?

Regards, NH Homesteader

Is this going to be a condensing unit as it would seem it's the high efficiency but possibly not condensing and is it oil or gas?

What are Buderus recommending themselves?

I can't comment on the flues you use there myself but i'm sure you'll get the right advice from someone on here.

This is a company whose products I use and can't fault them, they're French
http://www.poujoulat.co.uk/pro_produits_choix.asp
It might provide you with some beneficial information.

[NH Homesteader]

It is an oil-fired boiler, and I don't believe it is a condensing unit.

[flamefix]

Ahh with oil there isn't a condensing unit but they do state the following

"High efficiency cast iron sectional boilers, with Thermostream technology that can be used with either an oil or gas burner, and easily upgraded using external condensing heat exchangers."

It will give you higher efficiencies and reduce your flue gas temperatures as a result which may mean the flue liner might be cheaper or more expensive.
You don't get the same improvement going to condensing with oil as you would with a gas boiler but it may be a saving you might think beneficial.

Perhaps worth asking about...

[zl700]

Either way efficiency wise its still oil, thus SS liner required
Every liner company has a sizing chart to select proper size based on BTU's, height, conector rise/run, # and type of appliances.