Oil Boiler- New liner-No draft improvement?

[Billy123]

Oil boiler, 80. 000 btu. I had a liner installed this summer (5.5 inches) but my service guy the other day says the draft is about the same as it was pre liner, not too good. The run is about 18 feet with new cap on top. They did run into a problem with a tight area during installation in which the connected a piece from the bottom with a the piece from the top. The problem area was about a few feet above where the vent enters the chimney. Would you expect better draft with the liner or does this happen sometimes? Should I be concerned or let it go?

Other than the draft, the furnace was clean said the tech.

Any ideas?

 

[bholler]

Oil boiler, 80. 000 btu. I had a liner installed this summer (5.5 inches) but my service guy the other day says the draft is about the same as it was pre liner, not too good. The run is about 18 feet with new cap on top. They did run into a problem with a tight area during installation in which the connected a piece from the bottom with a the piece from the top. The problem area was about a few feet above where the vent enters the chimney. Would you expect better draft with the liner or does this happen sometimes? Should I be concerned or let it go?

Other than the draft, the furnace was clean said the tech.

Any ideas?

What size outlet does the furnace have? How many BTUs is it?

 

[Billy123]

80,000 btu boiler. Looks like a 6" outlet.

 

[bholler]

80,000 btu boiler. Looks like a 6" outlet.View attachment 256142View attachment 256143

So why did they go down to 5.5"? At 18' and 80000 btu you need 6" the whole way. Especially if the liner is corregated.

 

[Billy123]

I don't have the exact measurement, but I believe the space was only around 7 inches wide (rectangle)?

 

[mustash29]

No barometric damper?

Why all of the gaps at the pipe joints? Sealing them up tight will help improve the draft.

I'm wondering if that "tight spot" where the lower liner connects to the top liner might be a choke point or worse, a huge draft leak due to being poorly connected. Seems like a bit of a hack job to install it that way instead of trying to enlarge the tight spot. It was probably excess mortar that oozed out of the chimney block joint when it was originally built.

If that was mine I'd be rattling the liner folks cage to install it properly. And if my boiler guy was ok with a shoddy install like that I'd find a new boiler guy.

My parents had a 6" flex liner installed into the original 6x8 clay liner for their Quadra Fire 5100 insert. There were a few tight areas like this that needed to be enlarged. The installer still had issues getting the liner in so the entire length of the liner was "egg shaped" into a 5x7 but that was mostly to make it fit a 45 deg bend better. Because of the egg shape, 45 deg bend and corrugated liner, it can only be cleaned with a Sooteater.

 

[bholler]

I don't have the exact measurement, but I believe the space was only around 7 inches wide (rectangle)?

So then they had to remove the clay. Just because it's difficult isn't a good reason to put in a liner that is to small

 

[Billy123]

How much extra work is it to remove tile to fit a 6" and what typically is the cost?

Also, what is a typical number a service tech would get if the exhaust had a good draw? How do they measure that?


It was my cleaning guy who didn't like the way things looked including the new vent.

 

[bholler]

How much extra work is it to remove tile to fit a 6" and what typically is the cost?

Also, what is a typical number a service tech would get if the exhaust had a good draw? How do they measure that?


It was my cleaning guy who didn't like the way things looked including the new vent.

It is an extra hour of work if things go well. An extra day if not. There is no typical cost. I would need to look at the job to have any clue.

The draft specs would be provided by the furnace manufacturer.

 

[Billy123]

It is an extra hour of work if things go well. An extra day if not. There is no typical cost. I would need to look at the job to have any clue.

The draft specs would be provided by the furnace manufacturer.

I'm just wondering if I'm worrying about this too much since the unit is burning well?

 

[bholler]

I'm just wondering if I'm worrying about this too much since the unit is burning well?

That would be a question for your furnace guy

 

[Billy123]

If the draft were improved, what is the advantage?

 

[bholler]

If the draft were improved, what is the advantage?

The furnace will run properly. With inadequate draft you can have lower efficiency and there is a potential for overheating of the furnace leading to premature failure if the draft is bad enough. I just don't know I am not there and I am a chimney guy not a furnace guy

 

[maple1]

If the draft were improved, what is the advantage?

That kinda also depends on how much improved, and how it was before 'improvement.'

It might be fine the way it is - we are not there, and are not the oil burner tech.