Common Issues When Connecting New Gas Appliances to Older Chimneys

Common Issues When Connecting New Gas Appliances to Older Chimneys
Home-heating appliances like means a chimney or vent pipe.
For drafting to work right, the problems are bound to occur. This is all very relevant when connecting gas heating appliances such as stoves and fireplaces to older, existing chimneys. Just because a chimney is a “vent system” doesn’t mean it’s ideal for the new appliance.Incompatibility in this hookup sluggishly. Let’s look at both problems.

Dangerous chemicals within the flue

When the connector pipe on the new gas appliance is too small for the chimney flue, every time combustion happens, overproduction of acids and other chemicals will occur. Once example is the creation of hydrochloric acid that happens when chlorides in the air come into contact with condensation inside the flue. The result – either sooner or later – will be erosion of the chimney liner and areas of the masonry.

It’s bad enough to have this environment inside the flue. Worse is when hampered air flow causes combustion chemicals including deadly carbon monoxide (CO) to backdraft down into the home. CO is invisible and odorless, which means people can be poisoned by it before they realize they’re breathing it in.

Problems with air flow

A proper draft system will pull smoke and toxins up away from the firebox and channel them to the outside. When a gas appliance and existing chimney are improperly sized for one another, as noted, toxins produced through fuel combustion can flow backwards into the home.

The reason this happens, ironically, is because of the high efficiency of modern gas appliances. For example, gas fireplaces and stoves send the majority of their heat into the home, rather than up the chimney. If the flue is too large for the gas appliance, not enough heat will move up it to warm (lighten) the denser cold air high in the chimney. This makes it difficult for the lower volume of lighter combustion air to move up and out of the flue.

For these reasons, it’s very important to have your new gas appliance installed only by a certified chimney professional. This individual will thoroughly inspect the existing chimney and make any necessary modifications to ensure that proper drafting is achieved. Connecting a new gas-fueled appliance to a chimney designed to draft wood smoke is never a job for a novice.

Chimney damage signs

If you’ve been running a gas appliance through an existing chimney not specifically built for the appliance, signs of chimney damage you may notice include:

• Exterior chimney masonry that is discolored

• Blistering/bubbling paint on interior walls of the home

• Crumbling chimney bricks and mortar

• Ceiling staining

• Interior or exterior walls that are damp or wet to the touch

• Peeling wallpaper

Any of these signs of chimney damage warrant immediate service from a certified chimney technician before you use your gas appliance again. High’s Chimney Service of Gaithersburg, MD, is ready to help with inspection and installation of your new gas appliance, no matter what type of vent system you’re connecting it to. Count on us to do the job right and ensure the safety of you and your family. Call (301) 519-3500 to arrange a service call or to get your questions answered.