Will Oil Soot Rot a Polypropylene Chimney Liner?

curiousman

I read that even a little bit of oil soot can rot an aluminum chimney liner and I was wondering if it's ok to vent a polypropylene liner up a flue that was used for an oil boiler?
I'm considering a condensing boiler and venting it up the chimney. I saw a chimney being lined with polypropylene on you tube and the material look rather flimsy.

HVACNUT

It would have to be approved by whatever manufacturer you choose. I know the EK Resolute can be vented in polypropylene. Proper venting instructions of a boiler usually covers many pages in an I&O manual. Download the manual.
You shouldn't be too concerned with soot getting to the chimney. Today's technology and a good tech will prevent that. 

Jamie Hall

YouTube has some truly amazing things on it.

Oil soot won't rot polypropylene. That's the good news. Unless the polypropylene is specifically approved by its manufacturer and by the manufacturer of you boiler for that application -- which since the maximum rated temperature for the stuff is only about 275 F is highly unlikely -- you'd be insane to use it.

GW

Hmmm good question, but I would think the appliance would plug solid before the flue even begins to build a sheen of soot (if there’s a combustion problem) 

curiousman

The guy who gave the estimate said I could vent the condensing boiler in the old oil flue which hasn't been cleaned in many years if ever?

STEVEusaPA

You should not have had an oil appliance firing into an aluminum liner.

curiousman

I never said I had an oil fired appliance going into an aluminum liner. I know oil soot rots aluminum. I want to know if it's ok to vent a condensing gas boiler into an chimney that is currently used for oil. I'm converting from oil to gas.
All I want to know is ok to vent a polypropylene liner into the old(no longer being used for oil) chimney. A simple direct question that really only needs a yes or no answer. Thank you.

mattmia2

i think the question is if any residue from the old oil equipment in the old chimney lining will damage a new liner inside that old liner for a new gas appliance.

Jamie Hall

curiousman said:

I never said I had an oil fired appliance going into an aluminum liner. I know oil soot rots aluminum. I want to know if it's ok to vent a condensing gas boiler into an chimney that is currently used for oil. I'm converting from oil to gas.
All I want to know is ok to vent a polypropylene liner into the old(no longer being used for oil) chimney. A simple direct question that really only needs a yes or no answer. Thank you.

No

curiousman

If the answer is no, that means the guy who was here to give an estimate is wrong because he said it was ok to vent the condensing boiler into the old oil flue with a polypropylene liner.
I'm curious to know why it's not ok in your opinion.

GW

Wow I missed that one, didn’t see the word “gas” in the initial post. Yes, drop the pp liner, soot won’t hurt it. If you throw the scrap pieces of pp in the dump, it will be here for a long time 
flimsy- yes! Just follow the instructions 

curiousman

Thanks Gary, I know your a big on Viessmann which is one I'm considering.

HVACNUT

@curiousman, you never mentioned a gas conversion in your first post. A simple yes or no answer requires an specific question. 
Yes, you can sleeve the poly through the existing chimney. 
Does the manufacturer allow you to pull combustion air from a different location or is it also going through the chimney?
If you're worried about residual soot in the chimney, have it swept first. 

Jamie Hall

Am I missing something? Polyvinyl chloride (PVC) I can see as a liner. But polypropylene?

STEVEusaPA

curiousman said:

I never said I had an oil fired appliance going into an aluminum liner. I know oil soot rots aluminum. I want to know if it's ok to vent a condensing gas boiler into an chimney that is currently used for oil. I'm converting from oil to gas.
All I want to know is ok to vent a polypropylene liner into the old(no longer being used for oil) chimney. A simple direct question that really only needs a yes or no answer. Thank you.

Don't be an a-hole and word your questions a little clearer.

curiousman

Sorry but I thought I asked a detailed question but I think the confusion was that I didn't specifically say "gas condensing boiler" I only said "condensing boiler" because I thought that all condensing boilers are gas? Keep in mind I'm not in the trades and have very little knowledge about all this. I've learned to be skeptical of what people tell me and that's why I like to ask questions on this forum.

GW

Curious, it can get weird when you’re skeptical of those of whom you seek the advise. Ok you didn’t know your question wasn’t specific enough, fine. 

Steve that was a little rough 

curiousman

I didn't mean that I was skeptical of the advice from this forum. What I meant was when I get estimates from people who tell me something I like to seek other opinions. This forum is a good way to do that. I just need to be as clear as possible when asking questions.
You seem like a great guy Gary Wilson. If you worked in my area I would of called you for an estimate
As far as the Stevie in in PA comment, that doesn't bother me because I know that if he met me face to face I don't think he would say that to me.

GW

Lol what we type and what we say in person are two different worlds, it seems. And thanks, I’m just a working dude, like the farmer. I am hauling till the end, hope to have a nice retirement some day

STEVEusaPA

curiousman said:

I didn't mean that I was skeptical of the advice from this forum. What I meant was when I get estimates from people who tell me something I like to seek other opinions. This forum is a good way to do that. I just need to be as clear as possible when asking questions.
You seem like a great guy Gary Wilson. If you worked in my area I would of called you for an estimate
As far as the Stevie in in PA comment, that doesn't bother me because I know that if he met me face to face I don't think he would say that to me.

What I posted is 100% accurate. If someone else stumbles across the post, also misunderstanding your question, or wants to know if any oil appliance can be fired into a stainless steel line, they have the right answer.

BTW, don't back peddle after 2 other people said your question may have not been very specific and easy enough to misunderstand. Remember, you popped off first.
I don't like threats-online or in person, or bullies. I'm easy enough to find. I always treat people a little nicer than they treat me, until they don't. I'm the same way on the computer as I am in person.

curiousman

Sorry Steve but I think your making too big a deal of this. I was not disrespectful to anyone in my post. It was a simple misunderstanding.
I don't understand how you could ever construe any of my comments as a threat?

curiousman

Bingo!

mattmia2 said:

i think the question is if any residue from the old oil equipment in the old chimney lining will damage a new liner inside that old liner for a new gas appliance.

HVACNUT

curiousman said:

I never said I had an oil fired appliance going into an aluminum liner. (Ah, but you did. In your first post. That's what threw the alarm for @STEVEusaPA . You don't fire oil into an aluminum chimney.) I know oil soot rots aluminum. I want to know if it's ok to vent a condensing gas boiler into an chimney that is currently used for oil. I'm converting from oil to gas. (👈This is where we learn it's an oil to gas conversion.) All I want to know is ok to vent a polypropylene liner into the old(no longer being used for oil) chimney. A simple direct question that really only needs a yes or no answer. Thank you. (A little snarky with the tude right here.)


What we want to take away from this is we're here to help and there's no such thing as too much information. Pics are awesome. A verbal description by a layperson can sometimes cause a lot of confusion because we're not seeing what you're seeing. 
Sometimes it takes quite a few posts to get to the heart of the matter. 

So bottom line, I think, is what I posted earlier. Sleeving a polypropylene vent for a condensing gas boiler down an existing chimney is doable, as long as its within specs of the boiler manufacturer. Have the chimney swept if it's a concern. The better poly vents have feelers around its circumference to keep it centered in the chimney. 
You must also pay close attention to combustion air and where the manufacturer says it can and can't be drawn from. 

GW

Oh my, he said he “read” about this issue, he never said that he had an aluminum chimney liner. Holy Cow and Wow. We all understand it coulda been phrased better. gee wiz 

Bob Harper

Any time you change the fuel or efficiency of what's venting into a chimney, NFPA 211 calls for a level II inspection. If you're under the IRC, you're under 211 for heater venting.
The chimney would also need to be swept one last time.
Refer to the mfr. regarding incompatible materials but I'm not aware of a conflict with polypro in a chimney that once served oil. I am aware that even if you sweep it, any chimney that served oil or coal will rot an aluminum liner quickly.
HTH

Erin Holohan Haskell

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