Thread: Clip on fireplace damper

All gas log manufacturers require a clip on the damper to prevent CO2 flumes from entering the house when the pilot goes out if you have gas logs. If the damper is at the top of the flue and is opened and closed by a chain, does it require a clip?

Jim

Similar Threads:

• Prefab Fireplace Clearances
• Gas Fireplace Chimney Clearance
• Staining on damper
• Wood Burning Fireplace
• Fireplace Had It's Own Air Handler Unit

The damper is required to be blocked open. There is no CO danger if the pilot goes out though, the danger is when the fireplace is in use with the damper closed.

Thanks Jim,

I was under the impression also that if the damper was closed C02 gas could enter the living space and be fatal if the pilot were to go out and gas was dispelled.

Jim

If the pilot goes out due to lack of oxygen because of CO displacement... I think life would have been over for the occupants already.

The pilot light is kind of a red herring in the scenario.
The main issue is CO building up because of the closed damper.

As I tell my clients, there is no visual signal that you forgot to open the damper with gas logs as there would be with a wood fire.
You go to sleep with the gas logs going and just don't wake up

Jim,
CO2 is Carbon Dioxide.
CO is carbon monoxide, and is the concern here.

The 2 reasons for a damper clamp/stop are to allow gas leakage to escape out the flue, and to prevent CO from entering the home while the fireplace is fired.

If the pilot goes out, then the pilot safety (thermocouple/ electromagnet) should engage and prevent gas from flowing.

Originally Posted by JIM MURPHY

If the damper is at the top of the flue and is opened and closed by a chain, does it require a clip?

Jim

Yes.

Also the pilots are a herring as plenty of gas log sets have no pilot or safety valve, open valve, apply match to burner.

No need to over think this one........gas logs.......then damper must be locked in open position or removed........simple as that.

Whether or not a lock is present on the damper is not an issue with me. There doesn't seem to be much concern for standing pilots on a range or for the lack of a requirement that an exhausting hood be present. With all the air exchanges in a home, even a tightly constructed one I don't see where one little pilot flame is going to much of an issue. Obviously I'm not always railroaded into the thinking of others.

I call it out when its missing.

.....I don't think the issue is the standing pilot. The reason for clipped damper is so the log-set is not operated with the damper in the closed position. Unlike vent-free equipment, many log sets don't have oxygen depletion sensors and must be operated with damper open........Greg.

The position of the clamp on the damper is based upon the mfrs. listed instructions and the input BTU rating. Some local jurisdictions exceed this requirement such as the State of Mass, where dampers are required to be completely removed or welded wide open. Know that if the logset is controlled by a remote control, nobody is going to get up and open the damper before turning them on. All log mfrs. will tell you to open the damper wide open (just as with burning wood) before operating the burner. The language refers to the "minimum permanent net free opening". When you place the clamp on the edge of a throat damper valve plate, the MPNFO may be 10-20 inches if you're lucky. Most start at 50"sq., which is the equivalent of an 8" round pipe.

I hear you Eric but if a new owner operates logs with the damper closed, it can result in fire, CO exposure or soot particulate soiling of the house.

I put the clamps on the damper handle in the wide open position because so many people operate logs without thinking to open the damper. They can install glass doors to minimize air infiltration.