ProTech Systems Frequently Asked Questions

Frequently Asked Questions - Chimney Liner

Why Do Chimney Problems Occur?
What Other Problems Can Cause Chimney Damage?
What Can Be Done to Prevent or Solve These Problems?
What is a Chimney Lining System?
What is the Right Material?
Why Choose a VENTINOX Chimney Liner?
Can Aluminum Liners be Used?
What Material is Best when Relining for Gas?
What Material is Best when Relining for Oil?
What Material is Best when Relining for Solid Fuel?
Is Chimney Insulation Really Necessary?
Can I Install a Chimney Liner Myself?
What are Industry Standards?
What is a UL Listing?

Why Do Chimney Problems Occur?

Each year thousands of modern gas appliances are vented into outdated masonry chimneys, resulting in poor draft, excessive water vapor and corrosion. The chimney maintenance industry considers these problems serious because their effects do not show up immediately and the homeowner may not be aware that they exist.

In cold, oversize masonry chimneys, the low temperature exhaust gases of modern appliances rapidly expand and cool. DRAFT, which depends on the buoyancy of these gases, is drastically reduced. If the flue gases stay in your chimney longer, the danger of them leaking into the home increases.

WATER VAPOR is a normal by-product of combustion with any fuel. It condenses on the cool inside surfaces of masonry chimneys, especially those on exterior walls. The resulting water is absorbed by the chimney and transferred through the walls, causing paint to peel and wall-paper and plaster to fail.

In winter, wet chimneys experience numerous freeze and thaw cycles causing eroded mortar joints, cracked and spalled bricks, blocks and clay tile liners. Open mortar joints and flues blocked by debris can force carbon monoxide into the home.

CORROSION, usually associated with metals, can also occur in masonry chimneys, especially when they were previously used to vent oil and coal heaters. Chemical compounds, residue of these fuels and air pollution, combine with water to form acids capable of causing considerable damage to masonry materials.

A major industry study* identified indoor air pollution as a significant factor in the production of acidic condensation in modern heating equipment. The chemical compounds responsible for this acidic condensation originate from carpets, household bleach, cleaning solvents, laundry detergents, paint thinner, etc., ...items we all innocently use and store in our homes.

*1985 Gas Research Institute Study

What Other Problems Can Cause Chimney Damage?

Unfortunately, many times chimney problems go undetected or misdiagnosed. An oversize chimney without a liner reduces the performance and efficiency of any heating appliance.

Low chimney temperatures produce excessive acidic condensation on chimney walls, which causes deterioration both inside and out. Often times, costly repairs to a chimney are performed when a properly sized liner would solve the problem.

When burning solid fuel such as wood, dense creosote deposits left in your chimney can ignite quickly. In deteriorated chimneys, flames can escape to living space and spread rapidly throughout the home.

Damaged, blocked or improperly sized chimneys can create deadly toxins such as carbon monoxide. Leaking undetected through the smallest cracks or back drafting into your home, they can cause sickness and in some cases, even death.

What Can Be Done to Prevent or Solve These Problems?

Fitting a chimney with a properly sized liner is the best line of defense. This ensures good draft by preventing flue gases from expanding and cooling. The warm, buoyant flue gases exit the chimney faster and have less time to leak into a home or condense on chimney walls.

Water vapor in flue gases cannot be eliminated, but the amount that condenses in a chimney can and must be reduced. By properly sizing and then insulating chimneys, that goal can be achieved. Any remaining water must be contained within an air and watertight conduit. Porous masonry chimneys, chimneys with jointed clay tiles or interlocked stainless steel liners cannot do the job.

Keeping water inside the liner inhibits further damage to masonry walls from freeze and thaw cycles and corrosion. However, to contain the corrosive moisture, the chimney liner must be made from a material with superior corrosion resistance. Traditionally used aluminum and stainless steels are not suitable for long term exposure to acidic condensates.

VENTINOX stainless steel chimney liners are specifically designed to solve problems which may occur in gas, oil or solid fuel chimneys. Available in 3"-12" diameters, VENTINOX can be formed to any chimney shape, making proper sizing possible. VENTINOX is non-porous, leak-proof and may be insulated, perfect for reducing and containing condensation. To combat corrosion, VENTINOX is made from alloys recommended in the Gas Research institute Study for use with modern heating equipment. No other liner on the market comes close to matching the superior quality and established long term performance of VENTINOX.

VENTINOX is a registered trademark of American Boa. Inc.

What is a Chimney Lining System?

Most masonry chimneys are constructed with an inner liner of clay tiles. The purpose of this liner is to keep the heat of flue gases inside the chimney so the chimney can't overheat the nearby combustible material, such as the framing and walls of your house, and possibly cause a fire. The liner also keeps carbon monoxide, moisture, smoke, creosote, and other products of combustion from seeping through the bricks and mortar of your chimney and leaking into your home. As you can see, a secure lining system is crucial to the safety and well being of your home and family.

A Chimney Lining System it's what you need when the original clay tile liner was either never installed, or when the tile lining cracks, crumbles and deteriorates over time. Water damage, chimney fires, or just age can cause the deterioration of your clay liner. When that happens the National Fire Prevention Association (NFPA) code 211 says it must be replaced. The most popular, effective and economical way to reline your chimney is with UL listed, VENTINOX stainless steel chimney lining system. VENTINOX has been used for over 25 years in chimneys throughout North America and is the industry leader.

What is the Right Material?

Selecting the right stainless steel is one of the most fundamental of design considerations. The steel alloy must prove long term corrosion resistance when exposed to the often aggressive environments created during the combustion and venting processes of various fuels. All other features of a chimney lining system hinge on the correct raw material composition. Careful consideration for both metal selection and material thickness makes VENTINOX the top choice for ensuring ease of installation, safety and reliability.

Designing a lining system is a difficult task that requires hard choices, relating directly to product reliability, longevity and ultimately, the sense of security a good system provides to the homeowner. Wed like you to take a look at our criteria for making these choices.

VENTINOX super alloys consistently outperform aluminum and commonly available stainless steel liners in corrosive environments.

Why Choose a VENTINOX Chimney Liner?

All stainless steel liners are not the same. VENTINOX is UL Listed, has a lifetime warranty, and has been installed in thousands of chimneys over the past 20 years. Trusted in thousands of American homes since 1982 VENTINOX features the original WELDED design and is engineered with precision. The only time tested flexible stainless steel chimney liner, VENTINOX provides safe, reliable venting for gas, oil, and wood. When it comes to the best chimney liner for your home ask for VENTINOX.

With a success rate of 100% and no failures, VENTINOX is a product that performs now and for long time to come... Condensation can be stored in its corrugations and rarely reaches the bottom of the flue.

Its continuously welded design is completely air and watertight... no worries about carbon monoxide leakage or water damage. VENTINOX is available in 3 to 12 diameters and can be ovalized to fit any flue.

Protects against harmful flue gases
Improves chimney performance by creating strong draft
Preserves aesthetic appearances
Highly acid resistant
Water and gas tight
UL Listed for all fuels
Lifetime warranty by a reliable, solid manufacturer
The best stainless steel for many environments
Can be shaped without kinking or losing gastightness

Common stainless steel and aluminum do not withstand corrosive elements and condensation typical in gas & oil flues. Crimped seams can separate during installation. Continuously welded seam prevents flue gases and condensation from escaping. Pro-Rated warranties of limited durations exclude conditions typical for these environments. Minimal structural integrity. Often tears or pulls apart during installation or maintenance.

Can an Aluminum Liners Be Used?

If you are sure there wont be any condensation.
If you are sure no rain will enter into these liners and/or they will not sweat during hot and humid summer days.
If you are sure there are no sulfur deposits left in the flue from previous use (this can corrode aluminum liners from the outside.)
If you are sure this flue will not be used to vent any other appliance in the future (i.e. upgrading an old hot water heater).
If a five-year limited warranty is satisfactory to you.

What Material is best when Relining for Gas?

We strongly recommend stainless steel over aluminum liners and this is why. To the right is an aluminum liner only fourteen months after it was installed to vent an 81% efficient gas boiler

VENTINOX VFT is a very good overall choice for wood, gas and coal. It is the best choice for venting oil fired equipment.

VENTINOX VFT Titanium stabilized, Type 316Ti stainless steel is used to manufacture VENTINOX VFT. This alloy can withstand the high temperatures associated with solid fuel combustion; the corrosive elements typical in gas vents and the sulfuric acid exposure in oil applications. 316Ti exhibits good pitting resistance and is typically utilized in pressure vessels and chemical storage tanks.

VENTINOX VG The ultimate choice for venting gas heating equipment, VENTINOX VG is made from Type AL29-4C (S44735) stainless steel. This superferritic alloy can withstand the highly corrosive condensates (hydrochloric acid) formed in gas flues. AL29-4C exhibits extreme resistance to chloride pitting, crevice corrosion, stress corrosion and cracking. Therefore, this steel is typically used in power plant condensers and secondary heat exchangers. Introduced in 1986, VENTINOX VG serves in thousands of American homes today and has established a track record second to none.

What Material is best when Relining for Oil?

VENTINOX VFT is a very good overall choice for wood, gas and coal. It is the best choice for venting oil fired equipment.

What Material is best when Relining for Solid Fuel?

VENTINOX VFT is a very good overall choice for wood, gas and coal. It is the best choice for venting oil fired equipment.

VENTINOX HiFlex Our decision for using titanium stabilized, Type 321 stainless steel to produce VENTINOX HiFlex is based on conditions typically found in chimneys that vent fireplaces, pellet stoves or other solid fuel burning appliances, where chimney fires can create extreme temperatures and physical stress conditions. Type 321ss can withstand such severe heat exposure, while resisting intergranular corrosion and maintaining its physical strength. Typically used in aircraft afterburners, this titanium stabilized alloy is unmatched in the industry and has been successfully used to produce VENTINOX since 1982.

Is Chimney Insulation Really Necessary?

Definitely. Flue gas temperature is crucial to good draft and to minimize condensation, especially with higher efficiency stoves and furnaces. Liners in masonry chimneys have very high heat loss factors.

Without insulation, flue gas temperatures are lowered. This reduces available venting power (draft) and increases condensation.

Can I Install a Stainless Steel Liner Myself?

We know there are lots of people out there who like to do things around the house for themselves. We honor that desire. But when it comes to installing a chimney lining system, we strongly advise that you contact one of our registered dealers so you can be sure the job is done right.

There are too many things that if not done correctly could cause your chimney to violate the National Fire Protection Association (NFPA) Standard 211 code and prove to be a safety hazard for your family and home. Also, there are lots of opportunities for things to go wrong in the installation process that could cause you headaches and may threaten the integrity of your chimney if not handled properly.

Installing a liner requires the skill, knowledge, and experience only a seasoned chimney professional can bring to the job.

What are the Industry Standards?

In the National Fire Protection Association Standard for Chimneys, Fireplaces, Vents, & Solid Fuel Burning Appliances (NFPA 211).

In Chapter 10, maintenance section 10-9 it states: "Damaged or Deteriorated Liners. If the flue liner in a chimney has softened, cracked, or otherwise deteriorated so that it no longer has the continued ability to contain the products of combustion (i.e., heat, moisture, creosote, and flue gas), it shall be either removed and replaced, repaired, or relined with a listed liner system of other approved material that will resist corrosion, softening, or cracking from flue gases at temperatures appropriate to the class of chimney service."

What is a UL listing?

UL stands for Underwriters Laboratory. It is the leading independent organization responsible for setting safety standards and testing for a wide range of industries and appliances. If an appliance or device has a UL listing, it means it has been tested to UL standards as they apply to a particular industry or application and it has passed. The tests are stringent and rigorous in order to assure that only safe and reliable products receive the UL listing. A UL listing informs the consumer that the product he is buying has been suitably tested and found acceptable for the application for which it was intended.