QHT Boiler manual Chimneys, Chimney Construction, Chimney Cleaning, Downdrafts

Chimneys

WARNING

Do NOT connect this unit to a chimney flue serving another appliance.

Downdrafts

Downdrafts can result from improper chimney height, nearby buildings, tree that are taller then the chimney, and too large of a flue. To help minimize this problem, the top of the chimney must be at least three feet above the point at which it passes through the roof and two feet above the highest point of the roof. In addition, the chimney should be at least as high or higher than the tallest section of any adjacent roof.

WARNING

Chimney Construction

Fire insurance underwriters favor and sometimes require masonry construction for chimneys because tile- lined masonry chimneys are strong and not likely to crack from high temperatures.

Insulating your chimney flue liner will create a consistent natural draft by keeping the temperature of the flue gasses higher then the atmospheric temperature around the chimney. Insulation will also reduce creosote deposits by reducing the moisture condensation from the flue gases.

∙3WOOD must be connected to its own separate flue. It must NOT be installed in a flue which is connected to another appliance.

∙The recommended low heat, tile lined, masonry chimney should have a minimum 8”x 8” flue and be at least 18 feet tall.

∙A H.T. metal chimney is recommended and should have a stainless steel liner 7”ø.

∙The exhaust pipe should be minimum 24 gauge and 7”ø black or blued steel. It is suggested to point the male end of the pipe downward to prevent leaking creosote.

Chimney Cleaning

Check your chimney and flue pipe at least twice during the heating season. check it more frequently if you are new to wood or believe that there is soot or creosote build up.

A small amount of smoke can infiltrate the room when you refuel the boiler.

However, if this happens increasingly you may have a chimney blockage. To find out the cause, look into the chimney from above or below. If neither option is convenient, then use a mirror and a flashlight to look up the flue utilizing the clean out door as an access point.

To clean your chimney, you can contact a professional chimney sweep or use several do-it-yourself cleaning methods. The most efficient device for scrubbing your chimney flue is a wire chimney brush that is designed for cleaning solid fuel flues. These brushes are available in standard sizes for both rectangular and round flues. Another option is to fill a burlap bag with straw or rolled up chicken wire, tie it to a rope and drop the rope down to a helper. You can then pull the bag up and down in the chimney to scrub away and buildup. Similar methods include using a bunch of tire chains tied to a rope or tying a burlap sack to the end of a long pole, provided your chimney is not to tall.

Chemical chimney cleaners such as “chimney sweep” are available. These products are added to the hot fire in order to break down the creosote. We do not know how their long term effects on a chimney or boiler, but we have been advised that any chemical salt added to the fire may cause corrosion in insulated metal chimneys, boilers, and stovepipes. In addition, these products can be harmful to your health.

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