Vent Free Fireplace Odor

This week I inspected a home with a vent free fireplace. They’re common in Central Mississippi.

After lighting the log set my nose picked up a distinct odor. It smelled like a mix of burning dust and a kerosene lamp. The seller had three dogs and two cats – all inside/outside pets.

If you’re having trouble lighting your gas log set or once it’s burning you smell an odor – it may be dust, dirt, pet hair or/and airborne particulate. It could also be the quality of the appliance or the log set’s fuel type.

If you see soot accumulating on your logs, then you can assume that carbon monoxide is also being produced.

Greg Tillotson – Gas Log Expert

Fireplace Odor

Here’s my short list of things that have the potential to cause a vent-free gas appliance to produce an odor.

  • Smoking in the house
  • New Paint
  • Recently Stained Wood
  • Scented Sprays
  • Cleaning Chemicals
  • Formaldehyde Coming From New Carpet, Drapes or Furniture
  • Scented Candles
  • Glade Plugins
  • Extreme Dust
  • Pet Hair
  • Improper air/fuel mixture due to household dust (service the system)
  • Basically any impurities in the air the appliance flame processes can produce an odor

A stale air smell can be created when airborne particulate is drawn into the gas log set as it operates (see how to clean the unit – below).

A vent-free appliance requires room air to operate. It draws air in through tiny ports near the burner. When the room air gets mixed with “dirty air” it can smell like a petroleum based product. During my inspection the kerosene type odor was most likely due to a dirty log set and could have been a combo of one or more from the above list.

BEWARE: Your fireplace should never smell like a gas leak. If you feel you have a leak – turn of the gas, leave the building and call the gas company.

Ventless logs are required to have an ODS (oxygen depletion system) and it’s a great idea to install a CO2 detector nearby.

It’s A Fact – Ventless Logs Have An Odor

Ventless logs do in fact produce an unmistakable odor, some more so than others depending on the quality of the brand. There is no way of preventing this, it is simply the nature of burning gas in your home without exhausting the fumes up a chimney. In a perfect world, the natural byproduct of burning “pure” natural gas is water vapor and carbon dioxide, neither of which have an odor. But gas is never 100% pure, so we end up with other byproducts. READ MORE

One of the best articles I’ve read on this topic

Cleaning Your Vent Free Fireplace Logs

Time needed: 15 minutes.

We know that ventless logs have an odor, but dirt and debris can make it worse. Here are the steps to service your log set. This tip can also apply to vent free wall heaters as well.

  1. What you need?

    Grab a vacuum, a can of compressed air and a damp dust rag. It’s best if you have the log set installation manual in case you have trouble resetting the logs in place. (it’s always best to keep all appliance manuals)

  2. Prep Work

    Turn off the gas feeding the log set. Find the shut off valve and turn the handle to the off position . Using your smartphone take a picture of the log’s configuration. Remove the logs and set aside – take as many pictures as you need.

  3. Remove Dust and Debris From Pilot Assembly

    Using the can of compressed air clean this hole from the pilot assembly.

  4. Clean the Main Burner Assembly

    Let’s clean the dust from the air intake going into the main burner(s) shown below (the assembly varies by model). To locate the main burn intake follow the gas tube supplying the burner. With the compressed air blow out all the burner port holes.

  5. Finish

    While you have the logs off vacuum dust and debris from the firebox and surrounding area. Use the damp cloth to remove dust from all burner assembly parts. Don’t forget to wipe the logs down/remove all the dust. Before you finish, most vent free logs have a retractable screen hanging over the firebox opening – wipe and over time keep it dust free as well.

    Using your photo guide or the drawing in the manual properly align and reinstall the log set over the burners. Turn on the gas. Follow the typical lighting procedures to light the vent free logs.

    Grab a cup of coffee or hot chocolate. Enjoy!

“Other” Vent Free Fireplace Information

Vent Free Wall Heaters: Should be sized to fit the area where installed and must meet any additional regional or local requirements. Generally speaking – 6,000 BTU units are allowed in bathrooms and 10,000 BTU units are allowed in bedrooms.

IMPORTANT: Vent-free gas appliances should be used as supplemental zone heaters and not as a primary source of heat – – except for short periods of time – example: during a power outage.

THIS GUY HATES THEM – READ WHY: Dr Allison Bailes wouldn’t have a ventless fireplace in his home and he suggest that if you have one – you simply don’t turn your vent free fireplace on – ever! “They produce a significant amount of water vapor that it gets dumped into your house and that’s not good for indoor air quality.” Dr Bailes also calls Bob Vila out for promoting ventless fireplaces and has plenty more to say in this article. And he shares this link: Letters From Vent Free Fireplace Owners.

Last Word: Vent-free appliances, like all gas appliances, should be inspected annually for proper operation by a qualified service agency. This typically consists of cleaning, checking the burner and inspecting the appliance’s other key components and ignition system(s). My tips above are for informational purposes. Contact a professional if you have any questions. In Central Mississippi get your vent free and vented fireplaces from Builders Specialties.

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