Gas Logs, Damper Clamps and Glass Doors in Cuyahoga Falls

Why the Damper Has to Stay Open on Vented Sets

Vented gas logs produce combustion byproducts, including carbon monoxide, that have to go up the chimney. If the damper is closed while the set is running, or if someone lights the logs forgetting the damper is shut, those gases come into the room.

A damper clamp or damper stop is a simple piece of hardware that physically prevents the damper from closing completely. It is installed on the damper blade or frame and holds a fixed opening. Manufacturers and most installation standards call for it on vented sets, and it should stay in place for as long as the logs are connected.

• Clamp types vary with damper style: rotary, poker or throat dampers
• The opening must meet the minimum the log set requires
• Rusted or warped dampers may need repair before a clamp can be fitted
• Remove the clamp only if the gas logs are permanently disconnected

Dealing With Drafts After the Clamp Goes In

The most common complaint after a vented conversion is a cold draft from the fireplace when the logs are off. With the damper held open, warm room air can rise up the chimney and cold air can drop down it, especially on windy days.

There are a few good ways to reduce that without compromising safety. Glass doors closed when the fire is off are the most popular. A chimney-top damper can also work if it is set up so it cannot close while the logs are available. What does not work is removing the clamp or stuffing the flue.

Glass Doors and Gas Logs

Many existing glass door sets in Cuyahoga Falls homes were made for wood fires. With vented gas logs, most log manufacturers require the doors to be fully open while the logs burn, because closing them can overheat the glass and starve the burner of air. Some door models are designed for gas use and allow different operation, so we read both the log and door instructions before advising.

With vent-free logs, glass doors generally must stay open during operation as well, since the burner needs room air and the heat has to get out into the space. A mesh screen in front of open doors keeps embers and curious hands away.

When doors cause problems

Signs that doors are interfering include soot on the inside of the glass, a pilot that keeps going out, and a flame that leans or shrinks. If you see those, open the doors and call us to take a look.

Vent-Free Logs and the Damper

Vent-free sets are designed to operate with the damper closed in many cases, which keeps the heat in the room. Some manufacturers allow either position, and some recommend opening it slightly during the first few burns while the logs cure. Because the set's label governs, we install according to the specific model and show you where the damper should be.

Even with vent-free logs, the chimney still needs to be in good shape. Water coming down a damaged flue can rust the burner and soak the ember bed.

The Rest of the Installation

With the damper and doors sorted, we run a gas branch to the firebox, bring the line through the masonry in a sleeve, install the key valve or control valve, set the burner, and place logs and embers by the diagram. Every connection is leak-tested before the first light. If your home's gas piping needs work, our Cuyahoga Falls natural gas line service can take care of it.

Prefer a sealed unit with its own glass front? See our gas fireplace installation in Cuyahoga Falls. For log materials and ignition choices, visit our regional gas log page.