Should I Turn Off My Gas Furnace in the Summer?

April 12, 2021
Gas Furnace

The sight of blooming flowers marks the end of the cold season and ushers in spring and summer. Although all you may be thinking about is a summer vacation, you need to think about what to do with your gas furnace. Switching it off will mean lower utility bills in the coming months.

One thing is for sure, you will not need your furnace or boiler in the coming months. If you have a traditional gas furnace, it has a pilot light that stays on every day of the year. Even when the furnace is not in use, this light stays on. If you have a newer furnace that runs on electricity, you may not have to deal with the pilot light problem.

What Type of Furnace Do You Have?

Your furnace is one of either of two types; water-based or a forced-air heating system. Whichever type you have, the system will have a flue pipe and a thermostat. The only difference between these two systems is in how they deliver heat to your house.

The water-based systems transport heat to your home as water or steam through a radiator, radiant floor heating, or a baseboard heater. These systems need a boiler. You may hear them being referred to as hydronic systems.

Forced air heating systems disperse heat in the form of warm air. The heat disperses through floor and wall vents. This system needs a furnace, and it is the most common system for homes.

Both the systems get power from combusted gas. The output of the system is determined by the thermostat setting. Most homeowners think that the gas furnace is off during summer because the thermostat is turned all the way down. However, as long as the pilot light is on, the furnace is consuming energy.

Why Does the Furnace Stay On During Summer?

Your furnace doesn’t go off even during the hot summer months. You need to understand how the two systems work so that you can know why they stay on.

The thermostat in a water-based system detects when the temperature goes below the set level. When that happens, the gas burner is engaged, and it starts drawing gas. The fuel ignites inside the combustion chamber. When the gas lights, the boiler starts heating the water.

This hot water circulates through the baseboard heaters or the radiators. Any emissions go through the flue pipe and the chimney. Once the water cools, it goes back to the boiler and is reheated.

The steam system works almost the same way. However, instead of circulating water through the radiator, the system boils water until it produces steam. The steam goes through pipes that connect to the radiator and heats the home.

Forced air heating systems work the same as hot water systems in the first four steps. They draw gas that ignites in the combustion chamber. The system then draws cold air from your home and heats it. Inside the burner, there is a blower fan that fans the heated air through feed ducts. The feed ducts then direct the heated air into floor and wall vents.

Just like in the water-based heating system, the emissions from the furnace go out through the flue pipe and chimney.

Because the thermostat of the system is turned all the way down, you would think that the system will not work at all. But that is not the case. The system still burns fuel.

Why Does Your Furnace Burn Fuel Even When The Thermostat Is Turned All The Way Down?

The Pilot Light

If you have an old furnace, 15 years or older, it will burn fuel all the time. These older systems have a pilot light that doesn’t go off. If the tiny blue light ever goes off, your furnace will not light at all. The idea behind the pilot light was to ignite the furnace automatically without you having to light it manually.

Although the pilot light was a brilliant idea, it makes the system less efficient. Its inefficiency goes beyond the fact that the pilot light doesn’t go off at any time. It affects the AFUE (Annual Fuel Utilization Efficiency) rating. AFUE rating shows the percentage of the gas used to generate heat from the total amount of oil the furnace burns.

These older systems have an AFUE rating of between 56% and 70%. Newer systems with an electronic starter have an AFUE rating of between 80% and 98.5%.

The electronic ignition is instant and doesn’t need to stay on at all times. Further, newer systems have other features, such as a sealed combustion chamber that reduces the amount of fuel they burn.

Using a Boiler to Heat Water For Other Uses

If you have a water-based heating system, you may be tempted to use the boiler to heat water for purposes other than heating. There is hardware to help you with that. However, this means that you need to keep the furnace on the whole summer.

If you decide to do that, you can use tankless coils, which will reduce the AFUE rating of your furnace to 25%. Indirect water heaters are more efficient than tankless water heaters. These systems come with a separate tank that stores the water after the heater boils it. As such, you will have hot water when you need it without the system cycling between on and off.

If the Furnace Powers an Outdoor Compressor

If you link your central air conditioner with your furnace, you can never switch it off during summer. Here, the furnace blower will be responsible for blowing cool air over the evaporator coils to cool your home.

By switching off your furnace in the summer, you will save on energy and pay lower utility bills every month. However, if you link your system to your AC, you need to keep the furnace on. If you use it to heat water, you may also not turn it down unless you buy a standalone boiler.

What Do You Risk When You Turn It Off?

If you turn off your system, you need to ensure that you sustain routine maintenance. After you switch it off, you need to thoroughly clean it to remove dust and moisture, and any other dirt.

If your basement gets damp in summer, then water might gather on your furnace and likely cause rusting. When that happens, you shorten the life of your furnace. Soot on the furnace can also cause corrosion, which further shortens the productive life of your furnace.

If debris gathers in your pipes and other parts, it might lead to expensive repairs after summer. However, if you still choose to keep the system off, you can schedule regular maintenance with a technician from C & C Heating & Air Conditioning.

Once you have decided that you need the energy savings from a shut-off furnace, you need to understand how to turn it off.

Contact the Professionals from C & C Heating & Air Conditioning

At C & C Heating & Air Conditioning, we service your home’s heating, cooling, air purification, and humidification and dehumidification systems in Roseville, MI. We have a team of technicians experienced in the installations, repair, and maintenance of these systems. We also offer HVAC components from Trane, Carrier, and Lennox. You can also get financing as a new or repeat customer. Call C & C Heating & Air Conditioning and speak to a professional about your HVAC system.

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