Gas Chimney Alert for the Merrimack Valley

There are currently Thousands of homes in the Merrimack Valley that have unlined chimney flues! Inside of these chimneys are old soft bricks and deteriorated crumbling mortar joints. When gas appliances vent into unlined chimneys the water vapor combined with condensation absorbs into the bricks and mortar. This eats away at the interior walls like cancer. Pieces of brick and mortar fall down to the bottom and could potentially block the furnace vent.

Your chimney’s gas heating flue is one of the most overlooked and neglected parts of your house. It’s also one of the most important things that you need to make sure is working properly. A blocked chimney could cause deadly carbon monoxide to spill into your home.

When a new more efficient heating system is installed, the internal deterioration increases rapidly. Newer gas heating systems have lower exhaust temperatures which cause more condensation in the chimney. This condensation never dries out and causes the inside to crumble.

When gas burns it produces water vapor and carbon monoxide. The gas exhaust causes condensation.

It’s impossible to inspect the internal portions of the chimney without using a video camera. Before installation of any new gas appliance, a chimney is required to be inspected and video scanned.

This tragedy in the Merrimack Valley brought to light some existing chimney problems that would still be undiscovered if it wasn’t for the fact that people just happened to have their gas furnace chimneys inspected.
Chimney blockages were discovered where carbon monoxide had been spilling into people’s homes and they never even knew about it.

Commonly asked questions:

Natural Gas burns clean? Why would I need my chimney looked at?

It does burn clean. The byproducts of Natural Gas combustion are water vapor, carbon dioxide, and carbon monoxide.
Water vapor causes major deterioration inside a masonry chimney made of old bricks, mortar, and clay. Small pieces of brick, mortar, and clay fall down to the bottom of your chimney and build up above the height of the vent causing a blockage. Now you are vulnerable to carbon monoxide spilling into your home.

But I just got a new gas appliance. Why would I need my chimney inspected now?

Newer, more efficient gas appliances allow more condensation inside the chimney. They have a lower flue gas temperature and produce more water vapor.

Why is it so important to have a chimney inspection and video scan?

A video scan is the only way to inspect for the following:

Hidden construction defects such as exposed wood, holes, old breaches (where something vented in the past),
Bathroom vent pipes, electrical wiring, etc. Residential building code states that a chimney flue shall be thoroughly inspected (includes video camera scan) prior to the installation of a new gas appliance or chimney liner.

Why is stainless a better choice than aluminum for a chimney flue liner?

Aluminum liners are very thin. They can get crushed, scraped, and mangled during installation. They can be destroyed quickly by oil and/ or creosote residue. They are thin like dryer vents and can be crushed very easily. Stainless is much thicker and stronger than aluminum. Stainless will hold up much better in a corrosive environment. Stainless will better contain the water vapor and Carbon Dioxide produced by a gas appliance. Most Stainless liners carry a lifetime warranty.

Why does my water heater need a liner?

When a chimney vented gas furnace is replaced by a more efficient direct vented (exhaust out the wall) furnace, sometimes the existing water heater is left behind by itself, venting into the chimney. Since the chimney was designed to vent the old furnace and the water heater it is way too large to effectively vent the small “orphaned” water heater. The large chimney leads to poor draft condition and holds a large amount of condensation. A properly sized stainless chimney liner allows for an appropriate draft. It will contain all the products of combustion (water vapor and carbon dioxide and monoxide).
Other options would be instant-hot wall mounted system, power vented or electric water heater.

My chimney has been fine for 30 years. Why does it need anything now?

For 30 years acidic condensation has been deteriorating the inside. If there is no cap the rain has been pouring down inside the flue for years. Little bits and pieces of debris have been building up over the years and could potentially block your furnace vent.

  • Have your gas lines and appliances inspected by the gas company.
  • Have your chimney inspected by a professional CSIA Certified Chimney Sweep.

At Sweepnman Chimney all of our Certified Chimney sweeps are trained to identify any and all problems in your chimney. After a very thorough inspection, we will offer recommendations to keep your family safe.