How to Shut Down Your Furnace for Spring

When the weather warms up, it’s time to retire the furnace for the season. But just letting it sit could make for costly repairs or replacements down the line. Here’s how to prep your furnace for its annual hibernation.

Know when it’s safe to shut down your furnace. Spring weather can be a bit unpredictable, especially depending on where you live. If you’re hesitant to shut down your furnace prematurely, wait until the temperature reaches 50° F consistently outdoors.

Replace or clean your furnace filters. This is simple maintenance you can do yourself to prepare your furnace for the next fall/winter season. It's important to know your filter type, location, and replacement/cleaning interval, which vary among furnace models. Consult your manufacturer's specifications.

Thoroughly clean your furnace. Wipe down your furnace to remove dust, moisture, and debris. Look out for water and soot depending on where you keep your furnace, as this may cause rusting and corrosion which may shorten your furnace’s lifespan. If you’re not comfortable inspecting what’s inside, a professional can help.

Schedule a professional checkup. Avoid an ill-timed breakdown or costly repairs by thinking ahead.  A pro can inspect your unit to make sure it’s in good working order before colder weather arrives again. This is especially important for older units. Most modern furnaces have shut-off valves that engage when problems occur, but many older units lack this feature. End-of-season maintenance is an opportunity to locate tiny cracks in the combustion chamber, which can leak deadly carbon monoxide gas. Catching problems before the next furnace season also gives you enough time to save up for repairs or a replacement if needed.

If your gas furnace is old enough to have a pilot light instead of electronic ignition, it's burning fuel constantly. According to The NEED Project, gas furnaces made 20 years ago are only about 60 percent efficient, meaning only about 60 percent of the fuel they use is turned into heat. Today's high-efficiency furnaces are up to 98 percent efficient. If you’re using an old unit, it could be time to consider a replacement. Although it's costly upfront, it will save you on bills in the future.

A furnace's efficiency is expressed in an AFUE rating or Annual Fuel Utilization Efficiency. When upgrading an old unit, we recommend buying a furnace with an AFUE rating of at least 90 percent. 

Most boilers are fueled by either natural gas or oil. There are differences in what you can expect from each in terms of efficiency and features. Like furnaces, natural-gas boilers have increased in efficiency in the last few decades. If you're considering a replacement, look for an AFUE rating of 90 percent.

With any boiler, consider a control system that adjusts run times and operating temperature to the outside temperature. A boiler should ideally operate at the lowest temperature that will still keep the house comfortable, and a good adaptive control system will achieve that.

However, this advice doesn’t apply to oil-fired boilers. Because of the chemical structure of oil, condensing the flue gases doesn't provide as much benefit as it does with natural gas. Additionally, oil boilers are prone to problems such as soot and corrosion at lower temperatures.

Consider a heating protection plan to safeguard your heating equipment. We offer plans that include annual checkups, cover repairs and offer credits toward replacements.