My boiler was running very hot and had some flames rolling out too. My heating guy opened it up and cleaned out the soot the best he could. It was completely sooted up. He blamed it on low amount of fresh air in the small boiler room.... so we cranked open the glass block window vents.

How often you recommend that a boiler actually be cracked open and clean out all the passages one by one?

Have you checked for proper flue draft? Most (all?) boiler manufacturers recommend an annual boiler servicing which would include an exchanger 'brush down'.

He took out all the duct work and felt the chimney to have adequate draft.

I owned this property since 2003 and never cleaned it. Perhaps it was time?

You bet it was. ALL the soot must be removed if you are to get proper combustion and efficiencies.

An annual cleaning is recommended, but if the burner is adjusted properly, the draft is correct, and it has fresh air inlets, there should not be any "soot" in the first place. Soot is the result of poor combustion, or an oil burner.

Thanks guys!! The "boiler room" is a closed off room with one solid door to the outside. It's about the size of a small bedroom and it has a 300k btu boiler and (2) 50gallon water heaters in it.

It has glass block windows with a 1 square foot window crank opening that I had closed all this time. I cranked open yesterday to get fresh air in there...

you require as a MINIMUM a 10"x10" fixed outside air intake louver

NOT a 'window cracked open'

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

thats the exact my heating guy calculated! What I meant was I cranked open the louvered window all the way.

I assume the heat from the boiler will keep the room warm that the open window won't freeze anything up even in the very coldest nights



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Typically, two permanent combustion air openings are required in an enclosure in which fuel-burning equipment is installed. One opening should be located 12 inches from the ceiling and the other within 12 inches of the floor. This will provide air circulation in to and out of the equipment room under normal conditions.

The actual sizing of the combustion air openings depends upon the manner in which the air flows from the outside of the building to the boiler room. For example, if the air is drawn in through horizontal ductwork from outdoors, then each opening shall be sized to provide a minimum free area equal to one square inch for every 2,000 Btu/hour of input of all fuel-burning equipment within the enclosure. Alternatively, if the combustion air openings vent outdoors (through an outside wall) or are supplied through vertical ducts, then each opening shall be sized to provide a minimum free area equal to one square inch for every 4,000 Btu/hour of input of all fuel-burning equipment in the enclosure. When ducts are used, they must have a minimum cross-sectional area equal to the free area of the opening

Copied and pasted from another site.

And that is 100 sq. in. of OPEN air, meaning you have to subtract for any grillwork or window "slats". A typical 10x10 louvered opening seldom has 100 sq. in. of open space. Typically, a grill/register has only 75% of its area for open space.

i know field control company makes a fresh air kit. there is a fitting that attaches to the side of the oil burner that accepts 4" flex vent piping. you drill a hole in the building and mount what looks like a dryer vent but has no flapper, just an stainless screen to keep critters out.
you do need to put a 4 inch tee inside somewhere that will open a damper should the outside vent ever get clogged.
[www.fieldcontrols.com]
much better way to go than a big opening in the outside wall.

Two openings, and if those water heaters are gas or oil, they have to be figured in, as well.

quote; you do need to put a 4 inch tee inside somewhere that will open a damper should the outside vent ever get clogged.

Which by definition means it has to be checked frequently, otherwise you will be back where you started and will NOT know it.

The upper one is a "safety" vent and should not be calculated for the combustion air.

Would it be foolish to worry that on a very cold night the wind will blow in a certain direction and freeze a pipe, even though the window opening is louvered and any heating pipes are perhaps 6 feet away?

IF it blew directly onto a pipe, it COULD cause freezing, but normally there would be enough latent heat in the room to prevent it.