Oil boiler flue vs pellet boiler flue

[hemlock]

Hello,
Is it possible to use the same flue for a pellet boiler as for an oil boiler, or would the whole thing have to be replaced? Thanks.

 

[Fsappo]

Oil requires class A, overkill for pellet. Depending on the pellet boiler specs, you may want to toss a liner in there for draft purposes.

 

[hemlock]

Oil requires class A, overkill for pellet. Depending on the pellet boiler specs, you may want to toss a liner in there for draft purposes.

I was hoping that if I go that route (swapping boilers), I could just use the existing flue as is. Replacing or changing the flue would be an expesive pain, given the location (right up the middle of the house, enclosed by finished walls). It is the flue that will end up being the deciding factor in my "conversion" from oil to something else.

 

[SmokeyTheBear]

You don't normally replace the old flue, but run a liner up it. Pellet devices operate pretty close to their operation limits, so a large flue may be too much for the combustion blower to be able to maintain proper draft.

You just run a stainless steel liner up the existing flue with a plate and cap at the top of the chimney.

 

[Fsappo]

Oil requires class A, overkill for pellet. Depending on the pellet boiler specs, you may want to toss a liner in there for draft purposes.

I was hoping that if I go that route (swapping boilers), I could just use the existing flue as is. Replacing or changing the flue would be an expesive pain, given the location (right up the middle of the house, enclosed by finished walls). It is the flue that will end up being the deciding factor in my "conversion" from oil to something else.

So your decision on a life changing $7-$10,000 pellet boiler install will come unhinged over having to drop a $400 4" liner down a chimney?

 

[hemlock]

Oil requires class A, overkill for pellet. Depending on the pellet boiler specs, you may want to toss a liner in there for draft purposes.

I was hoping that if I go that route (swapping boilers), I could just use the existing flue as is. Replacing or changing the flue would be an expesive pain, given the location (right up the middle of the house, enclosed by finished walls). It is the flue that will end up being the deciding factor in my "conversion" from oil to something else.

So your decision on a life changing $7-$10,000 pellet boiler install will come unhinged over having to drop a $400 4" liner down a chimney?

If I can drop a $400 liner down the chimney, no. If I had to replace an entire difficult to access chimney to the tune of several thousand dollars, then yes, it may have come unhinged. It snuffed out my plans for a wood boiler. I would have had to remove the old selkirk (5") and replace it with 6", which would have not conformed to the clearance required to combustables as it went up through the finished portion of the house (about 25 feet worth). It would have required some major renovations.