Liner to Liner connectors safe?

[Walt_85]

So I was doing my install yesterday and for whatever reason the flex pipe wound up getting cut just a few inches too short. Now before you say measure twice cut once, we did. Then measured again. And again. But after pulling the liner through the chimney we wound up not having enough pipe at the too to attach the end components. I'm suspecting compression and have tried pulling the pipe to stretch it, but that isn't working.

So the solution I found through parts websites is called a liner to liner connector. This seems like it should do the trick, but I wanted to check with the folks on here to see if there are any concerns with using one of these adapters.

Thanks in advance

 

[KaptJaq]

The flexible usually comes in 25' segments. If your chimney is over 25' you need a connector. They are fine if properly installed. I usually use three (3) rivets on each side in addition to the clamps that come with it.

KaptJaq

 

[altmartion]

here that it a grey area. you are not allowed to connect a liner to another liner, BUT, you can connect a liner to a piece of hard pipe. obviously it has to be approved and of correct size and material. if it is only a few inches or maybe even 12, I don't see an issue with hard piping the rest but it must be insulated. if it's over a foot I would try to sell the short liner and get a new one. just make sure this one is stretched completely out.

 

[altmartion]

The flexible usually comes in 25' segments. If your chimney is over 25' you need a connector. They are fine if properly installed. I usually use three (3) rivets on each side in addition to the clamps that come with it.

KaptJaq

you can get 100'liners if you want. that's why we can't connect them together. if they weren't available it would be different. are you supposed to put rivets or anything in a connection of multiple wall pipe? we can't can't here. plus sometimes it voids the warranty.

 

[oconnor]

You can connect the liner sections as long as you follow the manufacturer's instructions. That's the thing with manufactured items, there isn't a standard code like masonry products. Each product gets tested for compliance based on the manufacturers install and operating instruction.

It might be a good idea to use a section of solid liner at the top of the flue.

 

[mellow]

I had to use one when I switched out inserts, it was shorter than the one previous and I had to add more liner. It has held up fine for the past 3 years, just make sure it is stainless.

(broken image removed)

 

[KaptJaq]

you can get 100'liners if you want. that's why we can't connect them together. if they weren't available it would be different. are you supposed to put rivets or anything in a connection of multiple wall pipe? we can't can't here. plus sometimes it voids the warranty.

OP is referring to flex liner, single wall. Many online shops ship in 25' segments. If liner & coupler are listed & installed to manufacturer specs they are safe. Rivets add to strength so there are less concerns when sweeping.

When you say "we can't here" is there a code you are aware of?

KaptJaq

 

[altmartion]

OP is referring to flex liner, single wall. Many online shops ship in 25' segments. If liner & coupler are listed & installed to manufacturer specs they are safe. Rivets add to strength so there are less concerns when sweeping.

When you say "we can't here" is there a code you are aware of?

KaptJaq

yes, local code trumps all unless local code specifies otherwise. a lot of time this is a dumb law. most codes enforcers know squat. I deal with them weekly. some codes may refer you to a manual but only then is the manual the deciding factor. I also deep down think some of the codes in place are to benefit the contractor. as you said, online shops sell 25 foot lengths. a contractor can get them in much longer lengths. I agree with you about strength. the reason code and most manufacturers don't allow it is because you are penetrating both walls and promoting cross contamination, condensation and rot. they prefer clamps. i have never had a liner kit that suggested any thing other than clamps. in the real world, will it do harm? not likely but if it is not code, insurance company's can refuse to reward. they are ruthless and have seen it more times than i can count. if it was my own home residence and if it is truly only a few inches short , sure i would run a finish the run with ridged pipe. but it would still have to be done to code. i have had the codes guy sign off on some things that are not by the book but only because i had no other options and it was still safe. but i always, always make him sign something. usually an invoice because it is descriptive of the work performed.

 

[oconnor]

yes, local code trumps all unless local code specifies otherwise. a lot of time this is a dumb law. most codes enforcers know squat. I deal with them weekly. some codes may refer you to a manual but only then is the manual the deciding factor. I also deep down think some of the codes in place are to benefit the contractor. as you said, online shops sell 25 foot lengths. a contractor can get them in much longer lengths. I agree with you about strength. the reason code and most manufacturers don't allow it is because you are penetrating both walls and promoting cross contamination, condensation and rot. they prefer clamps. i have never had a liner kit that suggested any thing other than clamps. in the real world, will it do harm? not likely but if it is not code, insurance company's can refuse to reward. they are ruthless and have seen it more times than i can count. if it was my own home residence and if it is truly only a few inches short , sure i would run a finish the run with ridged pipe. but it would still have to be done to code. i have had the codes guy sign off on some things that are not by the book but only because i had no other options and it was still safe. but i always, always make him sign something. usually an invoice because it is descriptive of the work performed.

Your comment on most manufacturers not allowing it makes no sense - I've never seen a set of instructions that didn't have details on how to connect flex and solid liner sections, or what connector to use to connect two sections of flex liner.

I'll ask the question again - what code or instructions are you referring too? A link to the actual reference would be helpful for education purposes.

 

[altmartion]

Your comment on most manufacturers not allowing it makes no sense - I've never seen a set of instructions that didn't have details on how to connect flex and solid liner sections, or what connector to use to connect two sections of flex liner.

I'll ask the question again - what code or instructions are you referring too? A link to the actual reference would be helpful for education purposes.

i think with a liner maybe it's because they don't expect a connection except for the appliance and termination. i have to meet with vern, the codes inspector tomorrow and get the info. my book is at my office and i am not going there today. i will try to find something on the web, even though it is hard for me to do. lol

 

[oconnor]

i think with a liner maybe it's because they don't expect a connection except for the appliance and termination. i have to meet with vern, the codes inspector tomorrow and get the info. my book is at my office and i am not going there today. i will try to find something on the web, even though it is hard for me to do. lol

Thanks

 

[Walt_85]

Thanks for all the replies!

Oconnor: Why is a solid liner advantageous at the top of the flue? Versus the bottom?

Mellow: That's the exact fitting that I'm thinking is what I need.

KaptJaq: Thanks for the help! The entire liner is insullated and I will be insulating this fitting as well.

I think I need a little more explanation as to what the benefits are of connecting the flex liner to a solid liner over just connecting another section of flex liner. If it's only because some codes dis-allow connecting flex liner to flex liner, then I'm not terribly worred over that unless there are specific dangers involved with connecting two pieces of flex together.

The "codes" have been giving me a hard time throughout my planning process. Manufacturers get their products tested in a particular configuration in order to satisfy the majority of the market needs. That leaves the minority (those with uncommon instal requirements) out in the cold trying to piece together a solution. I would never have gotten anywhere if it weren't for the help on this site added to an understanding that business is out to help themselves and being risk adverse is part of that. My closest dealer told me I couldn't install a stove period, the second closest dealer said he could do it but it would cost $6K or more. I purchased pipe after researching and was then told it wasn't approved. Was also told no company made the top adaptor I needed anymore.

I know, for a fact, that if I were within the city limits and were subject to code inspections, this instal would not pass simply because I had to use a special adaptor that is from a different manufacturer than the rest of the materials. But I also know that each and every part that I have purchased for this install have gone through lab testing, just not together as a complete system. I also know that several experienced people on this site have given great advice about the different pieces that I've had to use.

So, my questions isn't about "code" or "approved". My question is basically, would you be comfortable using one of these flex to flex connectors in your own home with your spouse and child?

 

[oconnor]

My thought on using the solid up top is it is often easier to clean, and the top is usually where most of the creosote ends up. Also, it can be tricky shoving the solid section to the bottom of the flue in some situations.

As for a flex to flex connector - I have no issue using an approved part and method to join the two. As long as the piece you are using is designed for what you are doing, I'd be happy.

Who makes your liner? Are you certain they don't make a connector?

 

[KaptJaq]

My question is basically, would you be comfortable using one of these flex to flex connectors in your own home with your spouse and child?

Yes. And my parent's home also (1860's 3 story, wood frame, Queen Anne style). That was some flue to line.

KaptJaq

 

[altmartion]

i would be comfortable too. in all reality what can go wrong that would jeopardize the safety? personally i would connect to a ridged section to terminate.

 

[BrotherBart]

If it wasn't safe to connect flex to flex or flex to rigid half of the fireplace inserts in this country, that use oval to round sections, to get through the fireplace damper would never have been installed.

 

[PLAYS WITH FIRE]

I don't know if this is possible or not but why not a couple of appliance adapters at the stove(one inside the other). That should give the few inches right?

 

[altmartion]

I don't know if this is possible or not but why not a couple of appliance adapters at the stove(one inside the other). That should give the few inches right?

that brings up another question.
are you pulling the liner through the hole and connecting or are you running hard pipe into the chimney and connecting like that?

 

[Walt_85]

Again, thanks to everyone for all of the replies. The reason that I do not think adding a section of solid pipe will work is becuase of two reasons:

1) I'm using an offset box which was purchased as part of a kit and I'm assuming is supposed to only be connected to the flex pipe it came with.

2) I needed a factory built chimney liner adaptor at the top of my flue to keep the existing chimney air cooled. This adaptor was built to specs and accounted for the flex liner, so again I'm assuming that only flex liner is supposed to be connected to this adaptor.

So, those are the reasons that I don't think I can consider using solid pipe to get the extra length I need. My flex is Olympia 6" Forever Flex made out of the 316Ti stainless. I have checked Olympia's website, and unfortunately they do not appear to have a quick connect female to male liner connector. I will still call them and see if they have anything. Woodland Direct.com does have one of these adaptors made out of the 316Ti, but obviously it isn't the "Forever Flex", whatever that's worth.

BrotherBart: Thanks for the advice, that sure helps calm the nerves!

Plays With Fire: I'm not sure if I can stack appliance connectors onto the offset box liner connector. Is this a reliable connection? That would definitely be easier than using the liner to liner connector plus extra liner.

altmartion: Not 100% clear on your question (still really new to stoves, stove installs, etc), but before cutting the pipe 3" too short the plan was a straight run of insulated flex pipe from the offset box to the termination at the top.

Heres another question, if I go with the liner to liner connector and add more flex, should I add this to the top or the bottom? Does it matter? I'm thinking it would be better at the top because I think it would be easier to inspect during cleanings.

One more question, although kind of off topic. My 6" insulated pipe is inside an 11" ID double wall existing pipe. Once finished, there will be surrounds convering the space between my insert and the edges of the hearth. Do I need Roxul to cover the 1.5" gap around the bottom of the liner to keep cold air drafts from coming into the house or will the surrounds inhibit the air flow enough for the effect to be negligable? My concern isn't so much while the stove is running, but when it isn't running for whatever reason and we are relying on the heat pump to provide warmth. If I do need the Roxul, then can I just stuff it in the gap between the pipes, or do I need some sort of a block off plate that I've read so much about on this site?

Thank you all for all the help!

 

[PLAYS WITH FIRE]

I am not sure to be honest.....I only thought of this because at Lowes I believe, they had the appliance adapters for stoves stacked like cups if you will. I thought it was one long one when looking for one for my friend. I could ONLY assume that you could screw/rivet them together and now you get the picture. Is it legal/safe I'd personally do it but I let the experts say yay or nay.

 

[PLAYS WITH FIRE]

BTW, be sure to seal your offset box well! I bought one that looks like this:
https://www.hearth.com/talk/threads/magnaflex-offset-box.102715/

That thing will leak like a sieve! I had mine weld together but without some sealing/modification you essentially have about 10" chimney. Unless you get the draft going and then it will only suck through the offset box.

 

[mellow]

I did mine at the top, the reason is I do my cleanings top to bottom so I wanted that adapter as close to the top as possible so if I had an issue I could pull the liner up and get access to it. It has not given me any issues during cleaning yet, I was wondering if the brush would hang on it but it goes right on down, now I am easier on it at that spot just in case but no issues so far.

Stuff it with Roxul, if you want to build a block off plate you can, especially if the Roxul is loose fitting.

 

[altmartion]

I am not sure to be honest.....I only thought of this because at Lowes I believe, they had the appliance adapters for stoves stacked like cups if you will. I thought it was one long one when looking for one for my friend. I could ONLY assume that you could screw/rivet them together and now you get the picture. Is it legal/safe I'd personally do it but I let the experts say yay or nay.

I would just be careful of connecting too many together. it could dampen draft. are these ok for stoves? I know I have used them for dryers and range hoods, but I never thought about it for a stove. it would have saved me some sweat a few times.

 

[PLAYS WITH FIRE]

Oh, yea what I found was and they actually at the stove section on top of the NC30 and it was at Home Depot NOT Lowes. They were a woodstove mfg like Duravent or something. I was at both stores looking that day..

 

[altmartion]

Oh, yea what I found was and they actually at the stove section on top of the NC30 and it was at Home Depot NOT Lowes. They were a woodstove mfg like Duravent or something. I was at both stores looking that day..

good deal, I will definitely look into this for future jobs. thanks for the idea.