Furnace filters turn black quickly

how

Turn off the power/ open up the fan compartment/ check all sides of the flue pipe inside the fan compartment with a trouble light and a mirror for cracks or rust/ check the holding sleeves on either end of this flue pipe in the fan compartment for black exhaust markings.

old_squid

Take a clean piece of white paper, rub your finger on the filter where it's black, rub the black onto the paper, does it smear like it might be oily or act more like dust? Is it hard to wash off your hand?

Do you find this "black" anywhere else in the house? Time for the white glove test.

If the stuff on your filter smears, appears oily or is hard to wash off your hands then you're somehow getting exhaust products from your oil furnace into the air you breath in the house. If you only find it on the filter and no where else in the house I suspect there is a hole or leak in the pipe shown on your diagram just above the filter that goes to the chimney. If you find it all over the house then the hole or leak could be anywhere in the furnace.

Either way you need an oil furnace tech out to check things over right away to find where the crack/hole is and see if it's either something that just came apart and can be fixed or you might need a new furnace. The situation is dangerous for many reasons and should be resolved asap.

And the person that told you that oil furnaces don't create CO is .......... an idiot and shouldn't be the one working on your furnace or anyone elses in my opinion.

tls1

Hi all,

So the contractor came by today... again he said that oil furnace do not create CO (only CO2 Carbon dioxide)... I will interogate him on that!

Anyways, he took apert the back of the furnace and checked and there were no leaks. he also replaced the nozzle and tuned the air intake for optimal clean burn.

He added some cement to where the tin exhaust enters the cement wall for the chimney. There were some gaps and he felt some smoke might be getting back into the house and being sucked into the furnace. The cement wall is around 2-3 feet from the return. We also put some aluminum tape around the filter door to keep it sealed.

We discussed the cost of replacing the equipment and he said I should keep using the machine until it dies.... It's paid for... why spend the $$ if you don't need to.

A new electric furnace 23KW/1HP is around 3K$ + tax including removal of old furnace and tank. And add 240V wire (20$ per yard) and breaker.

New oil furnace + tank + chimney liner is about $6K,
New dual energy oil + electric furnace + tank + chimney liner is about $7500 + 240V wire.

Thoughts ?
Cheers!
Terry

beenthere

Adjusted for optimum clean burn? How did he do that if he didn't take a smoke reading and do a combustion test.

Carbon Monoxide is a by product of incomplete combustion, and can occur with any thing that burns. He may be use to Fyrite kits. Which only measured smoke, draft, flue temp, and CO2.

JScotty

As the post above this points out Carbon Monoxide is created anytime you don't have complete combustion. However assuming your furnace is properly set up even with a massive hole in your heat exchanger your CO detector will never go off. Because it only creates CO if it isn't burning right.

So just because your detector isn't going off doesn't mean your not leaking flue gas somewhere.