This is something I had no clue about and it’s something you probably need in your home to be to code (if you don’t have it already). If you have a furnace or water heater that vents through a masonry chimney, you should probably start thinking about a chimney liner. And here is how to install a chimney liner yourself.
WHAT DOES A CHIMNEY LINER DO?
Sometimes it is called a flue lining but what it does is directs the combustion products to the outside. Plus it protects the chimney walls from heat and corrosion.
So it directs the bad air from a water heater or furnace to the outside of your home. SIDE NOTE: High-efficiency furnaces are vented differently.
INSTALL A CHIMNEY LINER
Some links in this post are affiliate link for your convenience, click here to read our full affiliate policy.
Also, we are not professionals so do all your research plus check you local codes before completing this project!
AMOUNT OF PIPE
Before purchasing any pipe you need to know the amount and length of pipe. The easiest way to determine the length of pipe for the chimney is to get on the roof with a tape measure and measure the inside length of your chimney. We needed 18ft for our home (this is from the opening in the basement to the top of the chimney). Plus give yourself extra off the chimney top to be able to add a cap (some codes require a certain amount). So we purchased three 5 ft pieces and one 4 ft piece to give us an extra foot at the top.
Here is what it means when you hear double wall (two pipes in one!).
Now for the size of pipe, this depends on what you are venting and their sizes. For both our 80% furnace and water heater, we used 5″ pipe but please do your research to make sure you are using the right size.
Other pieces you will need:
- adjustable 90 elbow (to come out of the chimney)
- double wall pipe (to extend past the wall, we used a 12″ piece)
- cap (for the top of the pipe)
- 4″ easy-out draft connector (connects to the furnace or water heater)
- metal cover for the chimney (we had ours made to size along with our HVAC trunk line)
TIP: A furnace should be connected in all double wall but a water heater does not.
Pieces you could use to connect to furnace:
- swivel tee (5″x4″x4″ this reduces the pipe for the furnace & water heater plus tees it off)
- more adjustable 90 elbows but 4″ this time
- 4″ double wall pipe
Take your time and determine what supplies you need for your system. Here is an example of ours.
ATTACHING THE PIPE
Before anything can be attached you need to make sure that the hole inside the chimney is wide enough for the new pipe. I used our Rotary Hammer to chip away the brick to make the opening the right size.
Double wall pipe does not need to be screwed together, they connect together using the grooves in the pipe. They are connected when you hear a click.
So start attaching your liner together and feed it through the chimney. SIDE NOTE: We attached our adjustable 90 first then attached one pipe at a time.
TIP: This is at least a 2 person job because the pipe gets heavy.
Once the end or the 90 fitting is at the opening in the chimney attach the pipe that extends it past the wall, ours was 12″
TIP: The 90 needs to be adjusted so that the extension pipe has a slope up toward the chimney.
Then on the roof insert the double wall pipe through the metal cover of the chimney. We cut ours to look like teeth then added a clamp (DO NOT tighten too much because it can break the pipe). Next, attach the cap to the pipe, we used 3/8″ screws on this.
That is how you install a chimney liner but now you need to connect the rest to the furnace and water heater. I shared pictures of how ours was connected and I wish I could tell you how to connect yours but everyone would be completely different. So here again is pictures of ours to give you an idea.
I hope this helps you install a chimney liner for your home. Does anyone else need to do this?