If your downflow furnace struggles to heat your home this cold season, take steps to solve the problem now. Because downflow furnaces sit in the attic, they must have the ability to push heated air down into the home instead of up, which is how basement furnaces work. Sometimes, attics experience problems that interfere with a downflow furnace's ability to transfer heat, such as holes and weak flooring. You can improve the functions of your downflow furnace with the tips below.
Seal the Attic
If you haven't done so lately, it's a good idea that you take a moment to repair the holes in your attic. Damaged attic foundations can allow cold air to seep inside the room over time. The cold drafts of air can penetrate the metal heat exchanger of your furnace and confuse the limit switch.
The limit switch is a unique device that typically communicates with the furnace's burners to operate the appliance. Whenever the home's thermostat tells the burners to come on, so does the limit switch. The limit switch also sends electronic signals to the blower motor when the heat exchanger and burners reach a certain temperature, such as the one designated by your home's thermostat. But if the heat exchanger can't obtain a good reading from the thermostat because it's too cold, the burners and limit switch won't cycle off and on correctly.
Filling or covering the holes in the attic with mastic liquid sealant keeps the room warm. Mastic sealant is ideal for closing up large openings in metal, wood and plastic surfaces. To apply the sealant:
- Wipe down the areas around the holes with a damp rag, then dry them thoroughly.
- Use a caulking gun to place a thick layer of sealant over each opening until completely filled.
- Smooth the sealant with a wet spatula, then give the material at least 48 hours to dry.
The attic should feel warmer within a day or two after the sealant dries. You can also reinforce the flooring of the attic to improve the functions of your downflow furnace.
Clean and Seal the Attic's Flooring
One of the ways you can reinforce the attic's wooden flooring is to place a new coating of sealant over it, especially if you haven't done so in the past. Wood can experience a number of problems that damage it's integrity, such as moisture.
The moisture inside the flooring's wood may absorb the furnace's heat instead of let it pass through to the rest of the home. You may notice that your attic's flooring and the ceiling of your other rooms appear damp and moldy. If you don't take steps to dry and seal the attic's flooring, you may eventually need to replace it.
In many cases, the moisture can condensate on the housing of the furnace and rust it. A rusty furnace can stop working completely, which means that you must replace it in order to keep your home and family warm.
To reinforce the wooden flooring in your attic, follow the steps below:
- Use a stiff-bristled broom to remove dust, cobwebs and other debris from the flooring.
- Mop the flooring thoroughly with a product that doesn't rot or deteriorate wood.
- Dry the flooring with at least three circulating fans.
- Apply the wood flooring sealant. Follow the drying tips on the sealant's packaging.
After you complete the steps above, wait at least 24 hours to see if the home feels more comfortable. If the home doesn't feel warmer, contact a heating specialist for services. The furnace may have other problems to repair.
For more information about improving the functions of your downflow furnace, contact a contractor like those at Cape Fear Air Conditioning & Heating Co., Inc..