Things you should know before you reline your furnace or hot water heater:
Common State Department of Labor, Licensing, and Regulation states that…
“If you provide, attempt to provide, or offer to provide plumbing or gas services in the State without a license issued by the Maryland Board of Plumbing, you are violating the State Law and running a risk of going to jail. You must hold the proper category of license issued by the State Board of Plumbing in order to provide plumbing, propane gas, or natural gas services.
Master Plumber – Insured
Only insured master plumbers can enter into contracts to perform plumbing or gas services. Each master plumber shall display the master plumber license and the license number conspicuously in the principal place of business of the master plumber; and the license number of the master plumber license on each vehicle used on the job for providing plumbing services.”
Chimney.com, to the best of our knowledge, is one of the only chimney company licensed to do relining on gas appliances such as your furnace/boiler/hot water heater flue, for you must hold a master plumber (which we have) or master gasfitter license.
Most of the older homes in our area have flue sizes that are too large for today’s high-efficiency furnaces and hot water heaters. Therefore, WSSC (WSSC is the regulatory commission that sets the codes for venting of gas appliances) has set forth new venting codes for today’s high-efficiency appliances. In most cases, the old terra cotta clay flue is too large and needs to be down-sized. By relining the flue with a UL listed stainless steel liner, you are effectively downsizing the flue and creating the correct air space needed to meet the current codes; and have an appliance that is venting carbon monoxide correctly out of the house.
What dictates the size of the liner needed to vent fireplace is the height and width of the fireplace opening. The height times the width gives you the square inches of the opening. This number has to be divided by the corresponding number in the chart below. For instance, if you want to use a 10″ liner, you divide the multiplied opening size by the corresponding number of 78 square inches to get a value of 12.30.
The corresponding number that is achieved by dividing this liner number should come out close to 12.0. Our experience has shown us that anything up to a 13.5 will draft, but any farther off of the chart and the fireplace flue will no longer function correctly and a good chance stands that you will have a fireplace that puts smoke in the house whenever it is lit. There are some remedies for these situations such as installing an Exhuasto fan or possibly a smoke guard. These are not ideal solutions, and should try to be avoided.
Correct= 32×30 = 960/78 (10″ liner), 12.30, which is almost a perfect operating system Incorrect= 32×30=960/50 (8″ liner), 19.2 – too far off of the chart and will cause venting problems.
The stainless steel liners can survive the test of time, and our UL listed stainless steel liners carry a lifetime manufacturer warranty and installer’s lifetime warranty as long as the warranty guidelines are followed.
Our experience has shown us that a full-proof method of relining a fireplace or furnace flue has been with stainless steel. Our reasons for using a UL listed stainless steel liner are as follows: simply, we have found that replacing a deteriorated masonry flue with a similar masonry product typically won’t last. Once a UL listed stainless steel liner has been installed, the masonry behind it is only used as housing and no longer the device which vents the fireplace.
There are two ways to reline a flue; one is with a UL listed stainless steel liner and the other is with a spray flue liner. With the spray flue liner, you are essentially spraying new mortar over top of already deteriorating mortar. The chance of this adhesion lasting is not very good. Also, when using a spray flue liner you are reducing the size of the flue, which in many cases will create a very poor drafting fireplace. Therefore, we recommend using a UL listed stainless steel liner, that has a lifetime guarantee, and of which we have never seen fail.
We have done extensive research to find out if these spray flue liners meet code requirements for gas appliances. We have found that coating flue lining systems is not UL listed or code approved for the venting of gas appliances.
A lot of the determining factors in whether your fireplace needs to be relined or not are: whether or not there are missing mortar joints between your existing clay tiles; whether or not the mortar in your smoke chamber has been comprised due to age or water damage or other deterioration; and/or deteriorated or cracked flue lining.
Note: A typical visual inspection is normally adequate enough to be able to determine the condition of the existing system, however upon request we do offer camera inspections.
Woodstoves are the number 1 cause of creosote buildup which equates to the number 1 cause of chimney fires. A common mistake in installing a woodstove insert or freestanding woodstove is inadequately sizing the flue. Typically, this means venting it inside of a masonry firebox/smoke chamber that is sometimes 24″ in diameter when commonly a stove requires either a 6 or 8″ vent size. What should be done, is installing a stainless steel liner inside the existing chimney to match the vent size required by the manufacturer of the woodstove being used. This size is normally found on the manufacturers product info sheet (cut sheet).