Furnace problems

[Mrs. Krabappel]

I could use some input. My oil burning furnace is venting improperly. It's horizontal in my crawl space. It is relatively new, so I am assuming it was installed to code, but I don't know. When I bought the house 2 years ago it did not come up as an issue on the inspection.

Furnace guy comes and tells me it vents into a horizontal concrete chamber and then up a chimney. He says he's never seen a similar set up. He gives it the side eye and tells me the chimney is blocked and needs to be cleared. I pulled out a piece of siding at the bottom of the chimney and it was full of ashes and soot.

I take it my best case scenario is just a blocked chimney, but should I be concerned about the distance/angles the effluence has to take before it gets to the chimney? Any other concerns in the pics? The guy even mentioned I might need a chimney liner :gulp:

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[Highbeam]

Do you use this furnace? If the chimney has been blocked then where has the effluence been going? You do have CO detectors don't you? The flue run doens't look horizontal and only needs a minimum slope to work.

 

[Mrs. Krabappel]

So if the chimney is clear, I'm otherwise good to go based on what you see? It's been venting out cracks in the top of that concrete/stone chamber. I do have a detector. I used it up until last spring when I got the stove.. I would like to the option to use it sparingly now.

Thanks for your response.

 

[mrfjsf]

Other than your venting pipe looking a little leaky to me, the angle looks fine. The ashes and soot you have found could have likely been left from the old furnace. So long as you have a means of venting the flue gasses up an out of the structure without leaking back into the house, You should be fine. Your detector shold be able to detect this quite easily within the structure. The only time you need to worry about soot and smoke from an oil furnace is when the primary air control on the burner assembly is adjusted improperly or your flue damper flap is out of whack. Did he do a smoke test? How bout a C02 test or net stack temp?

C02 should be between .08 and .12%, smoke test should be between a 1 and 3 no higher than 4. Net stack temp should be in the 500 range, higher is bad, lower is good. Im guessing your tech made these comments on a PM call? I asssume he changed out your nozzle and oil filter?

 

[Shari]

Oh, Kathleen, I can sympathize with problems with oil furnaces! While our problem (crud in the oil screwed up flow from our oil tank) let me tell you a short story about lining a chimney: When I had a wood stove installer out here giving us an estimate he got up on the roof and also checked out our furnace flue from the top. He said some tiles were broke and offered to reline the furnace flue for a cost of $3,000+! Considering our oil furnace is now only used as 'backup' I said no way. Personally, before I would ever consider relining at that cost we would simply install a new high efficiency furnace which vents out the side of our house with pvc pipe. Cost of the new furnace and new venting is slightly less that the cost of relining our existing furnace chimney.

Shari

 

[vvvv]

I could use some input. My oil burning furnace is venting improperly. It's horizontal in my crawl space. It is relatively new, so I am assuming it was installed to code, but I don't know. When I bought the house 2 years ago it did not come up as an issue on the inspection.

Furnace guy comes and tells me it vents into a horizontal concrete chamber and then up a chimney. He says he's never seen a similar set up. He gives it the side eye and tells me the chimney is blocked and needs to be cleared. I pulled out a piece of siding at the bottom of the chimney and it was full of ashes and soot.

I take it my best case scenario is just a blocked chimney, but should I be concerned about the distance/angles the effluence has to take before it gets to the chimney? Any other concerns in the pics? The guy even mentioned I might need a chimney liner :gulp:

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metal pipe shows signs of rust & may leak if rusted thru. mpipes could have soot layer within to affect the drafting. barometric damper on the mpipes should be free to flop so to stabilize the draft when the wind blows & there should be no other ways for air to enter pipe other than the baro damper until the siderun enters the vertical chimni.
stick a small mirror in the hole @ vertical chimni bottom so u can see up the chimni, u can see obstructions during daylight. plug the hole with al foil covered fiberglass or however , try to get a tight fit to minimize leakage.
does furnace work now? did u have it cleaned & serviced?
metal in humidity like a cellar rusts & the long run of the metal pipe allows for lotta heatloss, cooling of the pipe can result in condensation of the fluegas which is acidic. in this case with infrequent use i might consider covering the barometric damper with al foil so that metal pipe gets hotter without the flapping & air entering, maybe

 

[Shari]

PS There is a market out there on Craig's list for used furnaces. Selling the old furnace would offset the cost of a new pvc vented furnace. Also, would the energy tax credit apply if you updated?

Shari

 

[vvvv]

i'd reach inside hole @ bottom of brick chimni & reach into the concrete box. might pull out a bunch of clogging soot. yours is the worst setup ive seen & dunno if real tech would work on it. Maine did some free furnace replacements thru its fuel assistance program. first they condemn the setup, then they fix.

 

[Later]

Looks like you have some issues with the smoke pipe from the furnace. If the bottom (that's where they usually rust through) is in OK shape, pick up some hi temp foil tape and tape all of the weak, gaping areas. The mirror check is a good idea, I wouldn't mess with the barometric damper. Actually, all rusted, gaping smoke pipe should have been addressed during the annual service.

 

[begreen]

The install is a little bogus, but up to the concrete box connection, not too unusual for a crawlspace install. Unfortunately that crazy connection is cooling down the exhaust and making go through a lot of unnecessary routing.

At the very least, someone needs to get in there with a soot vac and clean out the whole passage. Is the hole in the base of the chimney normally sealed? That isn't helping things at all. It needs to be sealed or have a normal cleanout door. Also, is the furnace the only thing that is on this chimney or does the furnace at least have a dedicated flue?

 

[Mrs. Krabappel]

Is the hole in the base of the chimney normally sealed? Also, is the furnace the only thing that is on this chimney or does the furnace at least have a dedicated flue?

It was sealed. I removed it to check it out. The furnace is the only thing on that chimney. The guy would not service the furnace until the chimney was cleared, which is kind of a pita because I took half a day off work to meet him and don't know when I can do that again.

PS There is a market out there on Craig's list for used furnaces. Selling the old furnace would offset the cost of a new pvc vented furnace. Also, would the energy tax credit apply if you updated?

I'll look into this but I am loathe to put serious money into what I want to consider a back-up heating unit. And I generally make just a bit too much money to be eligible for county/state programs. Last year I tried to get in on a weatherizing program but was ineligible.

THanks for all of your input. I'm going to go pour myself a weekend beverage, stoke up the woodstove, and try not to think about it for a bit.

 

[begreen]

I’m going to go pour myself a weekend beverage, stoke up the woodstove, and try not to think about it for a bit.

:lol: This may not be that bad. I'd get it cleaned out and run it for a season. If it works ok and you don't find serious soot accumulation in any area, then it could be fine for you backup heating needs. Worse case scenario would be to figure out a better way to direct connect to the flue. But take it one step at a time.

 

[homebrewz]

Hey, nice log cabin. My friends in Greensboro (you know, the flat end of the state) have the exact same style built in the 1920's. Maybe its common down there.

The furnace probably runs less because its newer and efficient and because of the wood stove. If it runs less, the chimney never really gets that warm/hot anymore and the effluent produced from burning oil is getting deposited in the chimney and probably leading to the breakdown of the clay liner. At least that's what my furnace guy said to me.

You need to find a better and more efficient path from the furnace to the chimney, and that chimney needs to be cleaned. If the liner is in not too bad a shape, relining could be done a few years down the road. Its a great DIY project if you're up to it.

 

[maverick06]

furnace problems..... my furnace wasnt lighting off... called in the heater repair guy ($209 but it was under warranty)... know why it didnt work? The problem was dumb operator... I had turned off the fuel shuttof over the summer to change the filter...... and forgot to turn it back on....

i really have to start tagging out equipment... I do it at work... should do it at home...

lesson learned....

 

[fbelec]

two other ways of venting that oil burner is
1: add a draft inducer into the smoke pipe.
2: for about a third of a new liner you could eliminate the chimney totally with a sidewall vent.
http://www.tjernlund.com/oilsidewall.htm
not hard to do. your oil guy could do it or your plumber that does heat.

 

[raven]

That is along run on that flue,looks like 2 ft jts. All in all i would give a thumbs up to looking into the Tjurnlund.. Just make sure you are dealing with someone who really knows oil burners, they are a good heating system . Some find them messy but when maintained properly they provide nice heat.It would be my guess that who ever installed that unit used what they had in stock rather than ordering one that would have reversed what side the flue exited the unit. But then again the duct layout may have been the deciding factor.With that exterior chimney combined with the distance of the flue i would be surprised if you are not getting condensation in the flue. Which in the long run destroys the liner and chimney . Aluminum flex liners are cheap and easy to cure that problem ,but in your case with that concrete flue extension from the wall to the chimney it could be a hassle. just my 2 cents