Chimney re-reline oil to gas conversion?

[nemojones]

Hi,

In March 2010 I had my chimney relined with a 6" UltraPro Liner, 316 Titanium-alloy steel, .005 thick. No insulation.

A few weeks ago I had the oil heat converted to gas and now have a Crown Cayman 138,000 BTU boiler. I figured I was good on the chimney since it had just been relined and the liner should have been good for oil or gas.

Wasn't too thrilled with the chimney guys who did the reline so I called out the big local chimney company to come clean and inspect now that the oil to gas conversion was done. Also asked while they were looking at it could they give me a price on insulating the chimney since it always bothered me that I let myself get talked out of the insulation the first time.

Second chimney guy says while he cannot fault the job that was done on the original relining, the relining was good enough for the oil heat but not good enough for gas. He is recommending that I reline again with a 4ply 316 Ti-Alloy Stainless Steel liner and wrap it with a high heat thermal blanket. I believe he also may have stated that the liner should be .006 but that is not in the written estimate. He also states that the liner is not up to code because there is no clean out. No pressure, I should be good for now, but eventually it will need to be done.

Assuming that what is actually installed in my chimney is the same liner that I have on the quote from the first installer, does this relining make sense? I am calling other outfits for second and third opinions.

My instinct is to trust this second guy since this is the big reputable chimney company in the area but it's a big bill to swallow.

Thanks
Nemo

[BaldLoonie]

Nobody here in gas country insulates their liners. We use aluminum kits. Haven't had any issues with condensation once the liners were in place. Code could be different your way. Might ask a city inspector.

[Gross]

Stainless steel liners are code in many areas as well as clean outs. IF your chimney is drafting properly, I wouldnt touch it. Have the chimney guy let you know what the draft is with the furnace running. If you have good draft, then it is doing its job.

[hearthman]

The big company is incorrect on several points. The original liner is fine uninsulated for oil or CAT I gas. The liner mfrs. recommend insulating liners because warm liners draft better but cementitious insulation first has to conduct heat away until it reaches equilibrium temp. I use dead air space as my insulation and it works great. BTW, you must insulate for solid fuel.

That liner comes with a transferrable lifetime warranty, which is tied for best in the industry. The .005 wall allows greater flexibility to get liners down without getting stuck. You can stand on this liner and it won't crush. Try that with aluminum.

There is no need to pull this liner unless it is damaged. This guy is just trying to sell you a heavy wall "killer flex" liner, which is usually almost twice the price.

Now, as for the cleanout argument: The code requires cleanouts in chimneys......in the section of the code where it tells you how to build a chimney. It does not state liners must have cleanouts. Cleanouts are for planned failure. They know terra cotta flue tile will fail so they want a trash can for it to fall into without blocking the breaching. I've heard arguments that a cleanout provides an inspection port. So does disconnecting the chimney or vent connector pipe where it attaches to the liner only this allows better access for inspection or sweeping. The code actually expects you to install liners with a broad radius sweep at the base as this is factored into the derating and is actually stated in the IRC Code Commentary. As for all the B-vent, factory chimney, L vent, and Specia Gas Vent mfrs., NONE require cleanouts as part of their listing.

Now, I know some guys will say the cleanout provides a place for oil soot to fall without blocking the flue. Let me say that first of all, if you have that much soot in an oil flue, you have major combustion problems that need to be fixed. Also, most oil soot will stick to the walls of the liner where it must be swept off and doesn't fall down by gravity so easily. If the homeowner and service tech are doing their due diligence, the flue will get inspected at least annually and maintained as needed without the need for a cleanout.

Now, cleanouts mean putting a hard 90degree offset into the flue causing flow resistance. Do you mean to tell me you want to add flow restriction to a combustion appliance installed in a modern tight house with a reduced stack temp?

Thank the big company but just have a pro inspect the liner for integrity. If they pack ceramic fiber insulation top and bottom you will have an air insulated chimney, which is like B-vent or L-vent.

[nemojones]

Thanks, guys.

The chimney is drafting properly.

I went into the conversion under the assumption that the relined chimney was safe and appropriate for natural gas. Sounds like that's the case. I'll probably still have one more guy look at it just to make sure that the liner on the contract is the liner installed, and then leave it alone.

Thanks again

[hearthman]

Don't know what's in your contract but the HS Ultra liner is .006 while the Ultra Pro is .005 if that helps