This is a common question that we get asked all the time. Most oil furnaces are burning fuel 24/7 and 365 days a year. So, it’s not surprising that we get asked about shutting down your furnace when you don’t need to heat your home. Surprisingly, the answer really isn’t a simple yes or no since it depends on the type of oil furnace you have, how it’s used in your home, and the risks you may face with your system.
There are 2 different types of oil-fired heating systems that are used throughout the U.S.
A water-based heating system provides heat to your home using either water or steam which runs through radiators, baseboard heaters, or radiant floor heat. They use a boiler to function.
A forced air heating system using warm air to heat your home via floor or wall vents. This uses a furnace to function.
Regardless of which type of system you use, it receives its power from oil in your tank and receives its output instructions based on a thermostat setting. So, even if your thermostat is turned down, is your system still running during the Summer? Well, yes.
So, why is my furnace or boiler using fuel in the Summer? It could be one of these 3 reasons:
- If you have a furnace that’s 15 years or older, it most likely has a pilot light which is lit 24 hours a day, 365 days a year. The thought was that by leaving it lit, it saved the owner time by not having to constantly light it. Newer furnaces can feature an electronic ignition, not a pilot light. Electronic ignitions allow your furnace to start without maintaining a flame to ignite the oil. These ignitions are a major contributor to the increased efficiency of newer furnaces.
- If you use your boiler as a water heater. If your boiler supplies your hot water, which is a convenient option, then you will need to leave your boiler on year-round – at least if you want hot water.
- You use your furnace as part of your cooling system. Some households opt to have their central air conditioning system work with their furnace to keep their house cool. Your furnace may be providing the power to an outdoor compressor and AC evaporator coil. The compressor keeps the evaporator coil cool with refrigerant to remove heat and humidity from your home. Your furnace’s blower then spreads the cold air from the coil throughout your home.
If you use your heating system as a source of hot water or as part of your AC system, then you certainly cannot turn your system off in the Summer.
Now if you have a pilot light and don’t use your heating system for AC or hot water, you might be thinking it’s safe to shut down your system for the Summer. However, there are some risks in doing so:
- When your boiler is inactive and off, it cools down and makes it a prime target for condensed water, especially if it’s in a basement that prone to being damp. The moisture can lead to rust and repairs.
- Corrosion. When shut down, furnaces are prone to corrosion from water and soot. Even without any moisture, soon can build up in the walls of your furnace and cause corrosion and shorten the life of your system.
- Debris in your tank. A lack of activity could be an open invitation for insects and spiders to make a new home in your vent pipes, fuel tank, and furnace or boiler. If enough debris gathers in the tank or popes, you could have some big issues come Fall when you fire it back up.
While many people don’t have the option to shut down their heating system during the Summer since it’s connected to hot water or AC, those who have the option may not want to risk the small cost savings of using less oil for the large service and repair bill that may greet them in the Fall when they turn the furnace or boiler back on. When asked this question by our customers, we make sure to explain how their systems may be connected to other functions and the risks they may face if they do decide to turn their heating system off. If you have questions or need a service appointment, don’t hesitate to call us!
