Flue pipe and foil tape on oil fired boiler

Patchogue Phil_29

What is the correct type/kind of flue vent pipe for a residential oil fired boiler? New Yorker S-AP, 6" flue , 1.15 GPH.

Reason I ask..... 2 days ago, I began to smell an acrid odor of flue gas in the boiler room. Just a hint. CO detector did not go off, nor did the smoke detector. I even tried a second CO detector in the room to be sure.

So I notice some soot marks around the "ribs" of the flue vent pipe (in the elbow where you twist to get a different angle). The joints of the vent pipe pieces have foil tape on them. So I get some foil tape and tape up the "ribs". 4 hours later the smoke detector goes off and there is a smell of melting plastic. No CO readings on either CO detector. I sniff around and find the sticky glue is melting on the foil tape and THAT is the smell.

OK, (1) what is the correct type/kind of flue vent pipe and (2) do you use foil tape on the seams? If so, I figure there must be a special foil tape where the sticky glue doesnt melt off and smell bad?

S Ebels

If you have

If you have soot coming from the joints of the elbows you may have some other issues going on. I would combustion test the boiler, take a smoke sample in the flue with a smoke pump, check draft in the on, off, cold and hot conditions and test your over the fire draft. Pull the flue pipe also and check to see if you have buildup that's partially blocking the breeching in the chimney. If all those are OK you may just have poorly made elbows.

Anymore, I use stainless pipe and elbows on about every natural draft appliance we service and/or install. We used to see 24ga smoke pipe on units that has been in use for 20 years with no problems. That was in the days of good steel, standing pilots and high flue gas temperatures keeping the pipe nice and dry. At this point in time, efficiencies are so close to condensing on a lot of stuff that the pipe just plain eats out quickly. AFA tape goes, I don't know of any "normal" types that will withstand the flue temps of your old oil boiler. Solve the problem that's causing the smoke/soot.

Patchogue Phil_29

Soot & Foil tape

Yeah, I hear ya about the soot. It was cleaned in October. Something is obviously not right. The unit is just over 12 years old. I plan on having a new system installed this summer, something that will get better "fuel mileage" like a 3-pass MPO.

Funny thing about the foil tape, there's been foil tape on the flue seams since installed, never had the glue liquify and smell like that. I guess I got the wrong type of foil.

Paul Fredricks_3

As a 25 year oilman...

> Yeah, I hear ya about the soot. It was cleaned

> in October. Something is obviously not right.

> The unit is just over 12 years old. I plan on

> having a new system installed this summer,

> something that will get better "fuel mileage"

> like a 3-pass MPO.

>

> Funny thing about the foil

> tape, there's been foil tape on the flue seams

> since installed, never had the glue liquify and

> smell like that. I guess I got the wrong type of

> foil.

Paul Fredricks_3

As a 25 year oilman...

I've got to tell you I hate that tape. It may have it's place on ductwork, but not on flue pipe, IMHO. The sections should be secured with sheetmetal screws and that's it. If you see soot marks where the pipes meet it most likely means that the unit is not not igniting properly. Could be adjustments, could be an improper nozzle. It is also possible that it could be a draft issue, but I'd put my money on the flame.

If I ran into this with one of our customers I'd check the nozzle type and replace it, check the electrodes, check the pump pressure, check the air, draft and nozzle assembly adjustment, using proper test instruments. And I don't care weather it was just cleaned or not.

Robert O'Connor_12

sounds like

a blocked (or partially blocked) chimney. I'd take it apart and check.


Robert O'Connor/NJ

JackFre

Some SS products that are

frequently overlooked are Dura-vent (Model DVL)and Selkirk's (Model DS)close clearance chimney pipe connector. These are available in 6,7,8" (SDV), and 6,8" (Sel). they were originally designed for reduced cleanance of wood stoves, but are actually L-vent approved. 90's, 45's, t's, telescoping sections. 10 yr warranty, etc.
Looks great and works really well.

Another product to consider is Pellet Vent. It too is L-Vent and available in 3 & 4". Works great for an uninsulated "straight shot" chimney liner...properly sized of course.

Back when Rich Krajewski from Brookhaven was working on the venting tables for 31 (which became Appendix E) we were talking about chimney performance. Rich said that with all the testing they did, regardless of the chimney construction or configuration the best thing that could be done for chimney performance was to install an insulated vent connector...and don't try to use an exposed end wall chimney.

Patchogue Phil_29

exposed end wall chimney?

Is an exposed end wall chimney a brick/rock/masonry chimney that is on the OUTSIDE of the house? If so is that because it can be very cold causing condensing of the flue gases and hindering good draft?

Steamhead (in transit)

\"It was cleaned in October\"

betcha they either didn't actually clean anything, or left the burner in such a sorry state of tune that it sooted up the boiler very fast. I bet when you open up that boiler it's almost completely plugged with soot, which would explain why the foil tape is melting. If the heat doesn't get transferred to the water, it goes up the stack!

As has been stated in other posts, a partially blocked chimney can cause this too.

Along with many others, I've said this before but will say it again: A properly-installed, properly-tuned flame-retention oil burner will NOT generate any soot at all. Period. Based on the age of your unit it almost certainly has this type of burner. So something is way wrong.

To get this fixed properly, go to the Find a Professional page of this site to locate someone who knows oil burners.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

JackFre

Pretty much

Virtually all vent systems will condense at some point. It is called the "wet time". The goal in successful natural draft venting is to have a vent system which will heat up quickly, dry off the instantaneous condenstion quickly and draw properly. Most masonry chimneys are oversized. When a gas expands it cools. The masonry absorbs the heat out of the flue gas. there isn't enough natural bouyancy to get the flue gases to rise and, well, nothing good happens from there. Put most of the chimney outside and surround it with ambient winter temps and problems frequently occur.

Couple that with inadequate combustion and ventilation air and all hell breaks loose