I want to remove an old fireplace and install a zero clearance fireplace. There is currently an 8" chimney/flue exiting the chase above the roof. Can a fireplace that requires a 6" flue be installed with a flexliner 6" inside the existing 8" pipe?
No, you will need to connect all-new pipe that is compatible with the new fireplace model, as this is the only way to get a proper, listed installation. The diameter/model of the chimney pipe needed will be determined by the model itself.
Submitted by:Tyler M. - NFI Master Hearth Professional on January 6, 2020
I have a zero clearance wood burning fireplace and would like to add a fireplace insert into it. Would I need to directly connect the chimney pipe to the insert or would the existing exhaust into the zero clearance be sufficient?
A continuous run of 6" flexible stainless steel chimney liner will need to run from the insert flue connection to the top of the chimney.
I am looking at the WRT4542 for my 1200 sq. ft. home. My question is, will the damper in the stove leak cold air when not fired? Also, will a vent kit do the same? Additionally, do I need a fresh air kit?
The WRT4542 fireplace has a fireplace built into the top of the unit and this will do a great job preventing too much cold air intrusion down the flue and into the house. You could also add glass doors to this unit to further mitigate any such cold air issues. There is no fresh air kit needed for the chimney, as the pipe itself is air-cooled with a 15-inch outside diameter pipe (it has a 12-3/8-inch inside diameter). We would recommend a fresh air kit to be connected to the side of the fireplace if it will be installed near an exterior wall or above crawlspace.
Submitted by:Tyler M. - NFI Master Hearth Professional on November 14, 2019
When using an oval liner, should the adapter be sized so that the liner fits over the adapter or inside of the adapter?
When using sleeves and adapters, the male end of the liner should always be facing back towards the unit. This allows condensation to run back inside of the appliance as opposed to down the exterior of the liner itself.
While longevity will depend on the amount or humidity in the flue gases, the typical liner can last for 20 to 25 years under normal conditions. In extreme circumstances where high humidity is present, the life expectancy can be cut in half.
Submitted by:Collin C. - NFI Master Hearth Professional on September 10, 2013
Should inner liner go inside outlet on box or should it be outside?
The general rule of thumb is for vent pipe to be installed male end down. So, the liner would go inside the flue outlet. Of course, most factory boxes require specific brands of pipe that feature locking tabs and ensure a proper fit/connection.
Submitted by:Kevin E. - Fireplace Specialist on July 9, 2013