oil burner

[bayfeet]

I'm running strictly pellets this winter, so the oil burner is justing heating heating the indirect hot water heater. The cellar is cold but overall not too bad. I noticed that I'm picking up more of a combustion smell in the cellar from the burner and was wondereing if this smell would increase with the cooler air? The boiler and burner were cleaned in late October and I've swept the flue and vacumed the cleanout. Any ideas or has anyone had similar circumstances. I'm loving it as far as not using oil.

 

[heat seeker]

Do you have an OAK? You may be drawing air (and odor) down your chimney if the house is under negative pressure, otherwise.

 

[bayfeet]

Do you have an OAK? You may be drawing air (and odor) down your chimney if the house is under negative pressure, otherwise.

Yes I am running an outside air kit for the stove and there is also one for the burner.

 

[darryl123]

what kind of boiler/burner is it. chances are the chimney is cooling off more without being run for heating and it is drafting down from being colder. the warmer your house is the worse it would get. heat rises inside the house and escapes thru the top floors and cold air finds its way into the basement. here we have a chimney on the outside wall and when the bricks get very cold there is a strong downdraft and it is almost imposable to light the woodstove without filling the house with smoke.

 

[Bioburner]

I had the same problem in my old house as the oiler did not run enough to heat the brick. Ruined the flue when it got real cold and had to go with gas with pvc for venting. Could be a negative for going to pellets.

 

[TheMightyMoe]

Does your boiler maintain a low limit or is it a cold start?

I know some people that heat with wood stoves, and they had to put low limits on their boilers (Keeps the boiler @ 140 minimum) to keep the draft from reversing in their flue. Not energy efficient, but stops the smell / fumes from drafting into your living space.

 

[darryl123]

you should never run the boiler so low as it forms condensation at low temps.. reillo makes a burner that has a door that shuts off the draft when its not running but most furnaces have a lot of air holes in them that let the air into the house.

 

[bayfeet]

you should never run the boiler so low as it forms condensation at low temps.. reillo makes a burner that has a door that shuts off the draft when its not running but most furnaces have a lot of air holes in them that let the air into the house.

Oil burner in basement, pellet stove on first floor inserted into fireplace. Two separate flues. The smell is from the basement after the burner has fired to heat the indirect hot water tank. The boiler is set at 160 degrees and the hot water tank is at 120. Carbon monoxide detectors on all three floors. There is a fresh air intake for the pellet stove and the oil burner. The fresh air intake for the pellet stove is piped about five feet up passed the flue seal off plate. The four inch exhuast stainless steel liner goes twenty five feet to the top of the chimney and terminates with a plate but has vents on the side for fresh air intake below. No smell in room where pellets are burnt. The smell is in the cellar after the burner has cycled on. Would a colder flue from less boiler/burner use cause this smell?

 

[jlupi]

you should never run the boiler so low as it forms condensation at low temps.. reillo makes a burner that has a door that shuts off the draft when its not running but most furnaces have a lot of air holes in them that let the air into the house.)))

depends on the boiler. condensing boilers go low.

Oil-fired appliances condense around 113-115F. gas boiler, condensation starts at about 135F. You do not want prolonged exposure of non condensing cast iron boilers to condensing temperatures because the condensate is acidic and will corrode the cast iron. So keeping the coldest water (the boiler return) above these temps is necessary. A typical space heating system is designed around a temperature drop of 20F from supply to return.

 

[velvetfoot]

I have been having the same problem. It's a little more prevalent now since I put in an electric water heater to replace the indirect tank fed from a cold start oil boiler. The oil burner doesn't (hardly) ever come on any more. Even when we still had the indirect hooked up, you could feel the cool air coming down the pipe when you stuck your hand through the barometric damper hole. I put in a Field Controls oil vent damper, which I think helped. (broken link removed to http://www.fieldcontrols.com/ovd.php) . For me, I think the smoke from the lower chimney gets blown by the prevailing winds into the general direction of the higher (fuel oil) chimney where it gets sucked down. The smell isn't overwhelming and the CO detector reads zero. Fooling around with the stack heights somehow might be the solution for me.

Hopefully my tale will help you in some way.

 

[darryl123]

http://www.woodheat.org/outside-chimney.html
here is an artical about the cold chimney and some effects that it has.
the whole house acts as a chimney and the hotter air goes out the top of the house and the chimney is colder and the replacment air goes down the chimney and the smell from the oil burner comes in with it.
yes a colder flue would cause the smell, during heating season the oil burner is running enough to keep the downdraft from getting started
what burner do you have? some of the newer burners have a post purge setting that runs the motor with the oil shut off for 30-60 seconds after it fires to clear the oil smell after shutdown.