Furnace Questions...

Our gas company refused to turn on our gas because the chimney needs a liner. Is this something they can refuse just because of a liner? The home is over 100 years old and it may need a liner or new furnace but I don’t think this is an emergency. The chimney is not leaking.

Can anyone tell me how old my furnace is? It’s an Armstrong gas forced air, model G531400 4AE37, Input: 140,000 (BTU rating?), Bonnet Cap: 112,000, Ser #R110287.

If I do need a liner, my decision will be to install a liner for $xxx or to install a new furnace that vents directly outside through a side wall and not vent through the chimney. I don’t want to spend a lot of money on a liner only to replace the furnace in a year or two. Any educated opinions? Thanks!


If there is nothing else being vented in to old fire place chase extend the flue in approved type B vent all the way up chase until it exits the top. The furnace should not be venting in to old stack anyways the gas will condenses in the stack before it reaches the outside and can cause condensation and other issues.

Yes, it happens all the time.
Just do as Rolland posted and you will be up and running.

I don’t know how old your furnace is, but depending on where you live and how big your house is, it may be worth installing a high efficiency unit that is direct vented - fuel savings alone will pay for the extra cost. Also, unless you live in a massive size home, 140,000 BTU is too big.

Apparently the part of the world you are living in Jeff is not the same as mine. ONG In Okla. Allows vents into a chimney liner or not and I agree with the other post you have to conform to the gas company rules or find a way around them as was suggested with the class B vent up the chimney. But If your chimney that is 100 years in age as some I observe in my area they have a offset near the bottom that can be kind of tricky building a offset into the vent pipe and lowering it from the chimney cap but that is the least expensive route to take.

That’s an odd serial number for Amstrong. Most are one letter, five numbers, three letters. Can you verify that number for us?

Over the years, Armstrong has been manufactured by various companies, but none of them use that specific type of serial number.

Prestons tells me that it’s manufactured between 1972 and 1976. (M#G53140)


This link will take you to metal fabs website. Flexible liners work well and are o.k. with most local codes.

Do yourself a favour and replace it with a high efficient - direct vent. Better move in the long run. IMHO.

I used this <a href=“http://www.cleanairheat.ca/lennox-g61-gas-furnace.php”>High Efficiency Gas Furnace</a>

Jeff, in case Mr. Anderson did not make it clear enough, yes the gas company can and will refuse to turn on your gas if they think something is wrong with your gas appliances, piping, installation or venting.
There are other options for chimney liner besides B vent, the guys who will not turn on your gas should be asked what they will approve.

Eric that is a 2007 post Jeff is long gone

must have been the ghost in the machine:D

Consult with the HVAC certified professionals. Every furnace has different specifications with different structure according to their functionality. Hence, it’s better to look for good HVAC system service provider company.