The Chimney Clinic
The Loc-Top damper is a common damper design for a top mount dampers. It is operated with a cable and handle but the damper itself has a spring assembly allowing it to pop up. These type of dampers are better for area's with snow fall.
The dampers spring assembly can get worn out over time and lose its springiness. It can also get excessive creosote build up at the spring joint. These will both cause the damper to fail and not open. You can tell if it is not opening by totally releasing the handle from its bracket. The cable should have tension on it. If it is completely slack then chances are the top spring has malfunctioned.
Examine the spring assembly and see if there is creosote build up on the spring. If there is clean it out and try the operating assemble again. If it is free of creosote then push down on the top of the damper and see if the springs are operating properly. if they are no then its time to buy a new top mount.
*Note in all top mount dampers it may also be possible a chimney fire occurred damaging the top mount damper.
The most common issue in a poker style is when a damper plate jumps its track or flips over.
The damper plate itself sits in a small groove at the bottom of the frame.
Correct operation of the poker requires a slight amount of pressure pulled
forward on the poker handle. This disengages the teeth on the poker from
its catch. Sometimes if a person pulls to hard or pushes it will create
leverage pulling the plate out of its groove or lifting it up causing it to flip
The repair is as simple as getting a flash light and correcting the placement of the damper. The bottom edge should sit in the groove of the damper frame as illustrated in the top picture.
Fireplace Damper Emergencies
Sometimes the biggest emergencies happen when we forget to open the damper before a fire has been started. You will know pretty quick if the damper is closed when smoke comes pouring into the house. We recommend the following-
If you have any other questions about dampers or would like us to come out and evaluate your damper situation for you please call or email
The Lyemance Damper is a top mount damper that works on a trap door gravity theory. It is operated by a cable and handle as well but when opened instead of popping up it swings open down. These dampers are not the best for high snow fall areas
Lyemance dampers are known for freezing shut. The surface is flat and will collect snow or rain and in freezing temperatures will freeze shut. Lyemance engineers have designed a kick on the inside to help break the frozen door open.
If you rep lease the handle and the damper does not open chances are just like the Loc-Top it is either built up with creosote or malfunctioned. To see if its frozen shut pull down on the handle as you were going to release it from its bracket then really jerk down hard on it. This will activate the kick piston on the top of the damper. This will help if its a slight freeze or a similar issue.
If that does not work then go to the damper itself and see if you can push down on the plate itself or use a flat tip screw driver to pry it open. Sometimes excessive creosote will build up on the channel the plate sits in sealing it closed, or creosote will have build up on the pivot hinges. Either way you should be able to get it open by pushing down on the side closest to the rear ridge.
Top Mount Damper Assembly
A top mount damper is usually used as a replacement for a damper that either broke or did not function correctly. The top mount damper is placed on the top of the flue lining and has a control cable running down the inside of the flue. The handle is then attached to bracket in the fireplace.
The handle which is normally on the fireplace face will just turn and the damper will not open.
The handle when turned either sticks or will not turn at all
If the handle just turns freely chances are the set screw needs tightened or is stripped. The set screw attaches the handle to the operating rod. If it is not tight it will not allow the operating rod to turn so the gear will open the damper frame.
If it sticks or does not turn at all it could be a couple things. If it sticks rust may have developed somewhere in the gear assembly. So some WD-40 sprayed onto the gear assembly should do the trick. If it does not turn at all it could be rusted completely OR the worm can be bent from heat damage. Inspect the rod and the worm to see if rust is present or if the worm is bent at all.
Cast Frame and Plate
The first type of damper is what they call an in line damper and frame. It is the most common damper type and consists of a cast iron frame that is built into the fireplace at the time of construction. A damper plate then sits inside the frame and is operated by a worm gear or what is known as a poker assembly.
The first thing to learn about dampers is the fact that there are many different types of dampers. So in order to try to fix the problem you need to know what type of damper you have and its operating control. We respond to customers with damper problems all the time so don't feel bad if your damper is giving you issues.