Should the end of my chimney liner look like this?

[KennyK]

I know that the full chimney kits come with a top rain cap that attaches to the liner and a plate to cover the rest of the flue with a hole for the liner to run through. My chimney has two flues and already had a rain cover that went over both. When the company lined my chimney a few weeks back, they had the rain cap that went with the liner. The installer said he could attach the rain cap and cut a hole through my existing rain cover for it to go through, but he said I didn't need it as I already had the rain cover, and that it would actually be better without it for my setup. I just took a look at it today, and I can see that there's a plate blocking off the flue (with lots of sealant around it) with a hole for liner to go through, and the line ends a couple inches before my rain cover (it's an 8" high rain cover). I'm attaching some pics here of the top of my chimney as they terminated it, and a stock pic of the kind of raincap that the kit came with but was not used. Hopefully what they did is fine, but please let me know if this shouldn't have been done this way and if I should ask them to come back to add the cap.

 

[bholler]

Your cap is to low. I like a single cap like that but it needs to be higher and there is a potential for smoke backing up the other flues. I dont see that problem often but the potential is there

 

[KennyK]

Your cap is to low. I like a single cap like that but it needs to be higher and there is a potential for smoke backing up the other flues. I dont see that problem often but the potential is there

That is a bummer to hear. Is this something that you think I should be significantly concerned by and that should be addressed immediately, or is it something I can just get to fixing if I have the company come back to sweep, which will probably be in a few months? Also, is the best solution to cut a hole in the existing rain cover and attach the rain cap that came with the liner to go through the hole and above the cover? Or, do you think it's better just to install a similar rain cover for the two flues, but one that is taller? The installer did seem a bit surprised that the existing rain cover was only 8 inches as he suspected it would have been 10 inches. If I do put on a similar rain cover but taller, how tall is good?

 

[begreen]

Are you currently getting smoke or a smoke smell coming out of the other fireplace? If not, it may be ok and can wait.

 

[KennyK]

Are you currently getting smoke or a smoke smell coming out of the other fireplace? If not, it may be ok and can wait.

The other flue is unlined (just brick no terracotta, no metal liner, etc.) and used for the exhaust for our forced hot air furnace (gas and not high efficiency). The furnace exhaust ties into that flue in the basement (one floor below the wood stove) via a sealed metal pipe. Thoughts?

 

[bholler]

That is a bummer to hear. Is this something that you think I should be significantly concerned by and that should be addressed immediately, or is it something I can just get to fixing if I have the company come back to sweep, which will probably be in a few months? Also, is the best solution to cut a hole in the existing rain cover and attach the rain cap that came with the liner to go through the hole and above the cover? Or, do you think it's better just to install a similar rain cover for the two flues, but one that is taller? The installer did seem a bit surprised that the existing rain cover was only 8 inches as he suspected it would have been 10 inches. If I do put on a similar rain cover but taller, how tall is good?

It may work ok as is. But

The other flue is unlined (just brick no terracotta, no metal liner, etc.) and used for the exhaust for our forced hot air furnace (gas and not high efficiency). The furnace exhaust ties into that flue in the basement (one floor below the wood stove) via a sealed metal pipe. Thoughts?

It really needs a liner. That gas exhaust will tear the chimney apart from the inside.

 

[zig]

The other flue is unlined (just brick no terracotta, no metal liner, etc.) and used for the exhaust for our forced hot air furnace (gas and not high efficiency). The furnace exhaust ties into that flue in the basement (one floor below the wood stove) via a sealed metal pipe. Thoughts?

Your other flue for the gas furnace needs lining too. The exhaust has a lot of moisture in it as well as corrosives that will destroy the mortar joints; trust me on this, rebuilt mine because of it. I think you would be better off losing the big cap and installing a separate caps for each liner. In order to get a double cap like you have tall enough, rain and snow will get into it.

 

[KennyK]

It may work ok as is. But

It really needs a liner. That gas exhaust will tear the chimney apart from the inside.

My furnace is probably over 25 years old and running somewhere a bit below 80% efficiency. I was told by an HVAC guy or home inspector when I first moved into the house seven years ago, that because it wasn't higher efficiency it was ok to exhaust out of the chimney without a liner, but perhaps that's incorrect information. Actually, when I recently had the other flue lined for the wood stove, the guy who did it said the same thing you did about lining the other flue. I've been thinking of installing a high efficiency heating system, which would probably direct vent out of the side of the house thus taking the exhaust out of that flue, but I have been putting it off for cost reasons. Now as I'm trying to do more heating with the wood stove (and am planning on getting a larger wood stove to do even more of my heating this way next season), I have been thinking of putting off the high efficiency system even more. However, if I do need to line that flue, which would require a 35-40 foot liner, I should perhaps just go for the high efficiency system (and in MA I can get a 7-year zero interest loan to put in a high efficiency heating system). I'm confused Thoughts?

 

[djkeev]

Do you heat with gas or with the wood?

If the gas is only extra boost heat, vacation heat, sick heat, etc and it works well, I wouldn't upgrade.

High efficiency is often equated with high headache!
Plus the cost of a new furnace may never be returned if you use it infrequently.

Now if your wood is only asthetic and an occasional temperature boost. The high efficiency will pay you back...... but you'll still have the high headache to deal with.

Yes, millions of highly efficient furnaces are burning every day. There are also millions of problems every year.

Dave

 

[bholler]

Do you heat with gas or with the wood?

If the gas is only extra boost heat, vacation heat, sick heat, etc and it works well, I wouldn't upgrade.

High efficiency is often equated with high headache!
Plus the cost of a new furnace may never be returned if you use it infrequently.

Now if your wood is only asthetic and an occasional temperature boost. The high efficiency will pay you back...... but you'll still have the high headache to deal with.

Yes, millions of highly efficient furnaces are burning every day. There are also millions of problems every year.

Dave

But without switchkng to a condensing furnace they will need a liner. So that cost needs factored in to

 

[KennyK]

Do you heat with gas or with the wood?

If the gas is only extra boost heat, vacation heat, sick heat, etc and it works well, I wouldn't upgrade.

High efficiency is often equated with high headache!
Plus the cost of a new furnace may never be returned if you use it infrequently.

Now if your wood is only asthetic and an occasional temperature boost. The high efficiency will pay you back...... but you'll still have the high headache to deal with.

Yes, millions of highly efficient furnaces are burning every day. There are also millions of problems every year.

Dave

I just started using a wood stove about a month ago with a very undersized stove due to clearance restrictions. For now it's been more supplemental heat (though for long stretches of the day it is all we are using for heat). I'm loving it, and my plan is to resolve clearance issues and get a much larger stove to use as primary heat source for next season. So, if everything goes according to plan, my furnace will be used infrequently starting next heating season, and I agree with you that under those circumstances it doesn't seem worth it to sink a ton of money into a new high efficiency furnace. However, as bholler wrote:

But without switchkng to a condensing furnace they will need a liner. So that cost needs factored in to

If it's not ok to run the current furnace exhaust into my unlined flue, then I have to take into consideration the cost of running a 35-40 foot liner down the flue (which is the other flue in the same chimney as my wood stove liner), whereas with a new high efficiency system I could direct vent the exhaust out the side of the house and thus not have the expense of the liner and labor. Obviously a new heating system would still be a lot more money regardless, but there would also be other benefits over the currents 25 plus year old furnance I suppose (including being able to add a zone(s) as currently the whole house is all one zone).

What I'd like to know definitely is were the people who told me that it was fine to exhaust my current furnace into the unlined flue as it is pretty low efficiency, and as such my understanding was the level of gasses that can destroy the chimney are minimal, or is this absolutely not ok? Incidentally, at least one chimney person years ago told me that it was ok, but my gas water heater was not ok to vent through an unlined chimney, so I lined the flue that was going into (a different chimney altogether).

@begreen @bholler, anyone else... any thoughts? Other alternatives?

 

[bholler]

I just started using a wood stove about a month ago with a very undersized stove due to clearance restrictions. For now it's been more supplemental heat (though for long stretches of the day it is all we are using for heat). I'm loving it, and my plan is to resolve clearance issues and get a much larger stove to use as primary heat source for next season. So, if everything goes according to plan, my furnace will be used infrequently starting next heating season, and I agree with you that under those circumstances it doesn't seem worth it to sink a ton of money into a new high efficiency furnace. However, as bholler wrote:



If it's not ok to run the current furnace exhaust into my unlined flue, then I have to take into consideration the cost of running a 35-40 foot liner down the flue (which is the other flue in the same chimney as my wood stove liner), whereas with a new high efficiency system I could direct vent the exhaust out the side of the house and thus not have the expense of the liner and labor. Obviously a new heating system would still be a lot more money regardless, but there would also be other benefits over the currents 25 plus year old furnance I suppose (including being able to add a zone(s) as currently the whole house is all one zone).

What I'd like to know definitely is were the people who told me that it was fine to exhaust my current furnace into the unlined flue as it is pretty low efficiency, and as such my understanding was the level of gasses that can destroy the chimney are minimal, or is this absolutely not ok? Incidentally, at least one chimney person years ago told me that it was ok, but my gas water heater was not ok to vent through an unlined chimney, so I lined the flue that was going into (a different chimney altogether).

@begreen @bholler, anyone else... any thoughts? Other alternatives?

The difference is higher efficency furnaces have more complete combustion and better heat transfer. That means that they put less heat and unburnt products into the chimney. That is good for the chimney but it also puts more water into the chimney which is worse. So yes a higher efficency furnace will destroy an unlined chimney faster. But a lower efficency furnace still puts plenty of moisture in the chimney and allot more heat and unburnt gasses which is still pretty hard on the brick and mortar. Not to mention it is completly against code. Who ever told you it was ok had no clue what they are talking about.

 

[KennyK]

The difference is higher efficency furnaces have more complete combustion and better heat transfer. That means that they put less heat and unburnt products into the chimney. That is good for the chimney but it also puts more water into the chimney which is worse. So yes a higher efficency furnace will destroy an unlined chimney faster. But a lower efficency furnace still puts plenty of moisture in the chimney and allot more heat and unburnt gasses which is still pretty hard on the brick and mortar. Not to mention it is completly against code. Who ever told you it was ok had no clue what they are talking about.

Thanks Bholler. It's amazing how many so called professionals either don't know what they are talking about or want to cut corners. So, I guess I'll have to give this some thought and look into prices for either lining the flue with the existing setup or putting in a whole new system.

Going back to the original question of this thread, any thoughts on how best to proceed with the end of the wood stove liner? I liked the chimney company that installed the liner and will probably have them sweep at some point after the heating season. Should I have them install the rain cap that came with the liner, perhaps cutting a hole in the rain cover? Orher thoughts?

 

[bholler]

Thanks Bholler. It's amazing how many so called professionals either don't know what they are talking about or want to cut corners. So, I guess I'll have to give this some thought and look into prices for either lining the flue with the existing setup or putting in a whole new system.

Going back to the original question of this thread, any thoughts on how best to proceed with the end of the wood stove liner? I liked the chimney company that installed the liner and will probably have them sweep at some point after the heating season. Should I have them install the rain cap that came with the liner, perhaps cutting a hole in the rain cover? Orher thoughts?

I would have a taller multi flue cap put on or a shorter top clamp system. I am sorry but cutting a hole in the cap for the other cap is just a rediculous solution.

 

[KennyK]

I would have a taller multi flue cap put on or a shorter top clamp system. I am sorry but cutting a hole in the cap for the other cap is just a rediculous solution.

Is a shorter top clamp system like the rain cap, but short enough that it would fit under the existing multi flue cap?

Back to the other flue for a moment - I had another idea (probably won't work, but I know I'll get good advice here). I have an unused 25 foot 316 stainless steel forever flex liner in my basement that I bought years ago cheap on Craigslist, before realizing I needed something a bit longer. It is too short for the flue to the furnace, and I know you can't attach two flex liners for a wood stove exhaust, but could I use that and attach it to another ten foot flex liner for the exhaust to the furnace? If so, it would at least save me some $$ in liner cost.

 

[bholler]

Is a shorter top clamp system like the rain cap, but short enough that it would fit under the existing multi flue cap?

Back to the other flue for a moment - I had another idea (probably won't work, but I know I'll get good advice here). I have an unused 25 foot 316 stainless steel forever flex liner in my basement that I bought years ago cheap on Craigslist, before realizing I needed something a bit longer. It is too short for the flue to the furnace, and I know you can't attach two flex liners for a wood stove exhaust, but could I use that and attach it to another ten foot flex liner for the exhaust to the furnace? If so, it would at least save me some $$ in liner cost.

Yes if you get the approriate connecters it is fine to join 2 peices.

 

[KennyK]

Yes if you get the approriate connecters it is fine to join 2 peices.

Great - things are shaping up! This may be my solution to not being out an arm and a leg, not destroying the chimney and having a safer home! As mentioned, I bought that liner a while back cheap (actually now that I think about it more carefully, the guy advertised it as a 30 foot liner, but when I got there, he realized he had made a mistake and it was 25 feet - it was cheap, so I bought it anyways. I've been thinking to resell it, but just never got to it - I'll be happy to put it to good use if I can do that now! I think in the spring I'll see if I can have the chimney company come, sweep, put the liner in the other flue and put on a taller multi flue cap. Hopefully they'll cut me a good deal for being a good customer!