Oil combustion smell

ed_17

I'm running strictly pellets this winter and only using the boiler for heating the indirect hot water heater and as a backup.  The basement is cooler but not too bad.  I've noticed that I'm getting more of a combustion smell from the burner than previous years.  The boiler and burner were tuned in October and flue has been swept and clean out T vacumed out.  Would the cooler air cause the combustion smell from the burner to be more noticeable or is the burner not getting enough of a burnoff from less use? 

Rod

Combustion Smells

When you say you are using pellets, where is the pellet burner as related to the oil burner? Any chance that the pellet burner, when operating, is sucking some of its intake air from the oil burner? If so this, could be a very dangerous situation. Do you have carbon monoxide detectors in your house?

- Rod

ed_17

oil combustion smell

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? 

icesailor

Make Up Air

You have two flues?

The oil burner flue is providing make up air for the pellet stove when it is being used. The make up air is back drafting through the oil burner.

The house is too tight and needs make up air for combustion.

Its as common as the hair on a dogs back.

ChrisJ

Fresh air

When we had a pellet stove it had an optional fresh air intake kit.  If icesailor is right I recommend installing one if your stove / insert supports such a thing.