How To Install Vent Free Lp Gas Heater

How To Install Vent Free Lp Gas Heater


Sellers of unvented propane or natural gas-fi red supplemental room heaters shall provide to each purchaser a copy of 527 CMR 30 upon sale of the unit. Vent-free gas products are prohibited for bedroom and bathroom installation in the Commonwealth of Massachusetts. PRODUCT IDENTIFICATION UNPACKING 1. Remove heater from carton.

  • Jul 01, 1997 The main advantage of vent-free heaters, however, is also the chief drawback: With no vent, the byproducts of combustion may degrade indoor air quality and increase moisture problems. Although gas is a relatively clean-burning fuel, it does cause some pollution. Natural gas (methane) and bottled gas (propane) are compounds of hydrogen.
  • How do I install a vent free propane Heater?! I bought a new Charmglow 28,000 btu vent free propane heater to put in my basement. I have a propane furnace in the basement and I know I have to tie into the furnace line. I bought a line from Home Depot and a shut off valve, I know I have to turn off the propane supply in the basement and I'm not.
  • Hello, I'm installing a wall mounted vent free 30,000BTU propane heater. I need to install the supply line directly through the exterior wall underneath the heater to the outside. The propane company said they usually just hook up to a 3/4' black pipe on the exterior.

It’s chilly out here today. You know, this is my first winter here in this shop and already it’s become apparent that I’ve got to have some heat out here. Now, I don’t need to keep this at a constant temperature, that is, a living temperature, but I do want to be able to get the heat up quickly when I need it. So, I settled on this unit right here. It's called the hot dawg. Now this heater comes in 4 different sizes. 30,000 BTUs, 45,000 BTUs, 60,000 and 70,000 BTUs. This is the 60,000 BTU model right here and this is the one that's the right size for my shop. So let's get started. We're going to put this up. There we go. Now this heater is designed to attach directly to the bottom of the joist. But in this case, I want it mounted at an angle, so I've added a couple of 2 x 6's up here and lag screwed those into the joist.

Now since I'm going to be working alone today, one of the more challenging parts of this project may be hoisting this 80-pound heater up there where I'm going to attach it to those 2 x 6's. To start with, I've wrapped a couple of cargo straps around the case. A little research leads me to a marine supply store, where I check out things in the rigging department. Now, to do the heavy lifting today, I decided to use this marine block and tackle. It's designed to lift very heavy booms on sailing ships. Lightweight, very strong, a little pricey, but it's a lifetime tool. Now I'm going to attach it to this 2 x 4 that I put up earlier. The lower end of the block and tackle gets attached to the cargo straps. Then I hoist the 80-pound heater upward as easily as a sailor would raise a mainsail on the mizzenmast.

Once in position, I clamp the mounting flanges. And more clearance holes. Next, I insert carriage bolts - and finally twist on nuts and snug them tight with a socket wrench. Now this being a gas-burning appliance, I of course have got to exhaust those gases at a flue.

So the first thing I'm going to do is attach this T-shaped piece of flue to the back of the furnace right here. And I'll attach that permanently a little bit later on. Now there's going to be a second piece of pipe that will go from the center of this flue right up through the roof.

And that means we're going to have to cut a hole up there that's exactly on top of this one right here. So let's take a plumb bob. This is the best way to do this. I'm going to move it around up here until the plumb bob is centered directly over this flue.

Right, now I'll make a mark right up here at the top of the plumb bob line, right there. Next, I bore through the roof and insert a wire coat hanger. Well, the coat hanger marks the spot. We won't need that anymore. So let me push this back down through here.

Now what I want to do is draw a circle 6 inches in diameter - now this is a lumber crayon that I have in here - I bore a half-inch hole on the edge of the circle, insert the blade of the jigsaw and make the cutout. Well, this is the flashing that's going to make the watertight seal eventually around our flue.

I'm going to set this about where I want it here. And that is, I want to center the large opening down here on the bottom over that hole that we cut in the roof. That looks pretty good. Now I'm going to reach inside with my lumber crayon.

Be careful because this is sharp here - I'm going to trace the outline of this oval shaped base here. Then using a utility knife with a hooked blade, I cut along the mark that I just made. Next, I apply sealant to the lower shingles, where the base will be sitting on top.

Then I slide the flashing underneath the upper shingles and into the circular cutout. Finally, I secure the flashing base with roofing nails. This is double wall vent pipe. The inner liner's aluminum, the outside is galvanized steel.

Now the idea is that even though there are hot gases passing through this pipe, the outer jacket remains cool. So what I'm going to do is pass this up through that flashing we put on earlier. The lower end of the pipe I connect to the vent coming out of the back of the heater.

The joints are held together with couplings that snap into place. Back up on the roof, I slip a weather ring over the top of the vent and slide it down to the top of the flashing. Finally I set the vent cap in place and apply sealant to the nail heads.
With everything finished on the roof, I go back inside to make the electrical connections. Next I apply thread sealant to the gas pipe sections. Tighten them together and finally connect the flexible gas line. I installed the main part of the gas line and shut off valve earlier.

I've installed a programmable thermostat because out here in the garage workshop, I don't need heat all the time, just when I'm working. And the nice thing about this one is, if I'm coming to work at 9 o'clock, I can set this to bring the heat up around 8:30.

I can't tell you how glad I am that I put this unit in. In the few weeks since I've installed it, the temperature hasn't gotten above freezing and this heater has done a great job of giving me heat where I want it, when I want it.

Complete This One-person Installation of a Ceiling-mounted Vented Gas Heater in Your Garage or Workshop for Warmth on Demand

Select your garage gas heater by fuel type and BTU output appropriate for the environment. Our ceiling-mounted vented gas heater has an electric fan for circulation and a flue to vent fumes through the roof. A one-person project using block and tackle rigging to hoist the heater to a ceiling joist, it requires several trips to work from the roof.

Read More
  • Attach Two-by-sixes across Joists for Diagonal/Corner Mounting of Gas Heater

  • Lift the Gas Heater with Block and Tackle

  • Clamp the Heater to the Joists and Bore Clearance Holes

  • Secure the Gas Heater to the Joists with Carriage Bolts

  • Attach the T-shaped Flue and Mark Its Position at the Roof

  • Cut a Hole in the Roof for the Flue Pipe

  • Install the Funnel-shaped Flashing to Waterproof the Flue Opening

  • Install the Long Vent Pipe, Weather Ring, and Vent Cap

  • Make Required Electrical Connections for the Gas Heater

  • Connect the Rigid Gas Pipes and the Flexible Gas Line

Attach Two-by-sixes across Joists for Diagonal/Corner Mounting of Gas Heater

Lag-screw two-by-sixes across ceiling joists to corner-mount the vented gas heater. These gas heaters are designed to hang from the ceiling joists, but aiming flow from the circulating fan diagonally across the garage will improve airflow in this situation.

Lift the Gas Heater with Block and Tackle

Hook the upper end of a block and tackle to the beams and the lower end to cargo straps wrapped securely around the gas heater. Use the pulley to hoist the gas heater up to the joists and into position.

Clamp the Heater to the Joists and Bore Clearance Holes

Position and temporarily clamp the heavy gas heater to the joists along its mounting flanges. Bore equally spaced clearance holes for carriage bolts in the ready-made cutouts along the mounting flanges.

Secure the Gas Heater to the Joists with Carriage Bolts

Insert a carriage bolt into each clearance hole and tap the head with a hammer to seat its collar in the wood. Twist on nuts and then finger-tighten and then snug them with a socket wrench. Remove the clamps.

Attach the T-shaped Flue and Mark Its Position at the Roof

Attach the T-shaped portion of the flue to the back of the gas heater. Use a plumb bob to determine the exact vertical position above the center of this flue pipe on the underside of the roof. Mark it.

How To Install Vent Free Lp Gas Heater Parts

Cut a Hole in the Roof for the Flue Pipe

Bore through the mark, inserting a wire to locate the hole on top of the roof. Outline the diameter of the flue, centered on the hole. On the outline, bore a pilot hole for a jigsaw and cut the opening.

Install the Funnel-shaped Flashing to Waterproof the Flue Opening

Center and mark the oval opening of the funnel-shaped flashing over the cutout. Cut away upper shingles along the mark. Apply sealant to the lower shingles and slide the flashing base under the upper shingles. Secure with roofing nails.

Install the Long Vent Pipe, Weather Ring, and Vent Cap

Insert the vent pipe through roof and flashing. Connect the lower end to the T-shaped flue, securing it with snap-in-place couplings. Add the weather ring and vent cap to the upper end of the pipe. Add sealant to nail heads.

Make Required Electrical Connections for the Gas Heater

How To Install Vent Free Lp Gas Heater For Garage

Remove the side panel from the gas heater housing to access the electrical components. Match wires and secure with wire nuts, following gas heater manufacturer's directions to make electrical connections for components such as the air circulation fan.

Connect the Rigid Gas Pipes and the Flexible Gas Line

Apply thread sealant to the gas pipe sections and screw them together. Snug the fittings with adjustable wrenches. Connect the flexible gas line and tighten the nut. The main gas line and shut off valve were installed before this project.

Have your project done by a local, qualified professional.


Not everyone is in a position to do a project themselves. That's why I've partnered with to provide you with free quotes from qualified local professionals.

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An unvented heating appliance, also called a vent-free appliance, has no chimney vent and is located in the space being heated. Combustion products are discharged into the heated space rather than exhausted to the outdoors through a chimney. Typical fuels are natural gas and LPG (propane). While convenience is the major advantage of vent-free gas heating products, the degradation of indoor air quality is a concern. In some areas state and local codes regulate unvented heaters.

What are some of the advantages of vent-free heating products? Because no vent pipe or chimney is required vent free heaters are easy and inexpensive to install. Many heaters do not require electricity allowing them to be used for emergency heat. Most are quiet, easy to use, and efficient. In most locations in the country gas is a relatively inexpensive fuel. Many heaters are designed to create a comfort zone in a single room, reducing heating costs.

What types of vent-free heating appliances are available? Small portable units for use in a single room are manufactured for emergency heating–others are made to serve as a permanent heat source. Optional blower kits and ductwork allow them to heat two or more rooms. Available styles include cabinet mounted units, wall mounted units, fireplaces, and fireplace inserts with a variety of flame patterns including blue flame, infrared, yellow flame, and glowing logs. Sizes range from under 5,000 Btu/hour to over 38,000 Btu/hour.

Vent Free Heaters

How efficient are direct vent heating appliances? While the flame burns with over 99 percent efficiency not all the heat is available. Approximately 9.6 percent of the heating energy available in gas comes from burning the hydrogen which produces water vapor. To recover this heat, the water must be condensed. With an unvented heater, the water vapor condenses on room surfaces, which increases the potential for wood rot, peeling paint, plaster failure, and mold growth. To prevent wet windows and walls, the vapor must be prevented from condensing, reducing the maximum efficiency of the heater to 90.4 percent.

Unvented heaters release pollutants into the house. Once combustion pollutants are in the house outside air must be provided to dilute and remove the contaminants. The additional ventilation needed to reduce pollutants to tolerable concentrations depends on the tightness of the building and the health of the occupants. Heating cold outside ventilation air reduces the thermal efficiency of the heater. The National Fuel Gas Code, commonly used in determining outside air requirements, is based on 1.0 air change per hour (ACH). Providing 1 ACH to a 10 x 20 foot room in Iowa would require over 1,000 Btu/hour, which is over 25% of the output of a 3800 Btu/hr heater.

What pollutants are released into a room when an unvented heater is used? The main combustion products formed when gas burns are:

  • Carbon dioxide (CO2), a non-toxic gas formed during complete combustion of carbon based fuels.
  • Carbon monoxide (CO), a toxic gas formed if combustion is incomplete.
  • Nitrogen dioxide, a toxic gas.
  • Water vapor.

What about carbon monoxide risks? CO, a colorless, odorless, tasteless, non-irritating poison, is highly toxic and can cause death or permanent brain and organ damage. CO poisons more people than all other poisons combined. When properly maintained and adjusted, gas heaters produce low amounts of carbon monoxide. One cause of carbon monoxide poisoning from unvented heaters– incomplete combustion caused by lack of air–has been virtually eliminated in newer heaters by use of Oxygen Depletion Sensors (ODS). Unfortunately, the ODS does not respond to incomplete combustion caused by improper gas pressure; dust, dirt, or rust on the burner; incorrect placement of artificial logs in a gas fireplace; or disruption of the burner by air currents. CO poisoning from unvented heaters remains a concern.

What is the hazard of carbon dioxide? CO2 is not toxic. At high concentrations it can cause sleepiness, headache, and contribute to the “stuffy” feeling of closed houses. All unvented gas heaters, even when burning properly, produce large concentrations of carbon dioxide, raising the levels of in the house. What is the hazard of nitrogen dioxide? NO2 is a toxic gas that at lower concentrations is an upper respiratory irritant causing cough, sore throat, headache, vertigo, and nausea. Some NO2 is always produced in a burning flame, the amount depending on burner size and design. NO2 is linked to an increase of asthma which occurs in winter.

What is the hazard of water vapor? If a home is too dry, water vapor is not a hazard and some operation of an unvented heater will provide needed moisture. If the home is already too wet, any operation of an unvented heater will increase the moisture problems. The amount of water produced from burning a fuel is large, with over 4.8 gallons produced in 24 hours of operation of a 28,000 Btu/hour natural gas heater.

Can the health hazards of an unvented heater be reduced? The most effective method to reduce the hazards is to discontinue use of the unvented heater by switching to vented gas or electric appliances. Where unvented gas appliance use is permitted the following are suggested:

How To Install Vent Free Lp Gas Heater

  1. Use only approved gas heaters with ODS pilots.
  2. Follow all operation and maintenance instructions carefully.
  3. Clean the burner yearly, or more often, as required in the owners manual.
  4. Do not use an oversized heater. The Gas Appliance Manufacturers Association (GAMA) recommends limiting the amount of pollutants by correctly sizing the heaters. A 3840 Btu/hr heater is the largest that should be used in a tight 10 x 20 foot room located in Iowa.
  5. Do not operate for more than 4 hours at a time. Unvented gas heaters are designed for supplemental use only.
  6. Do not use unvented heaters in bedrooms, bathrooms, or confined spaces.
  7. Provide adequate ventilation, as required in the owner’s manual. If the home has weatherstripped doors and windows an outside air source will likely be required.
  8. Provide even more ventilation, or discontinue unvented heater use, if the pollutants cause health problems.
  9. Install a U-L or IAS listed carbon monoxide detector. Because low concentrations of carbon monoxide can cause health problems, purchase a detector advertised as a “sensitive” detector or one with a digital display.

Will a “properly sized” heater be large enough to heat the room in cold weather? Unvented heaters are meant primarily as supplemental heat sources. A GRI study conducted for the Gas Appliance Manufacturers Association noted that “it may not be possible to create a comfortable temperature” with a correctly sized heater. Alarger heater, in cold weather, will pollute the air beyond allowable standards.

How To Install Vent Free Lp Gas Heaters

What type of heater is recommended? A vented gas heater, a direct-vent wood stove or an electric heater will all provide enough output to safely heat a room for long periods of time. Combustion products from vented gas heaters or woodburning fireplaces also contain CO, CO2 , NO2, and water vapor. Improper design or installation can allow combustion products to enter the house. However, if the vent system operates correctly, all the pollutants will escape to the outdoors through the vent pipe. Pollutant levels will not increase.

Prepared by
T.H. Greiner, Ph.D., P.E.
Extension Agricultural Engineer

The Iowa Cooperative Extension Service’s programs and policies are consistent with pertinent federal and state laws and regulations on nondiscrimination regarding race, color, national origin, religion, sex, age and disability.

File: sep98AEN-204