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Commercial HVAC, Preventive Maintenance Agreements, Residential HVAC

Furnace Not Working? 6 Things to Check.

Last Updated on 

Last Updated on June 25, 2015


Have you been putting off turning on the heat in your building, hoping to avoid the high utility bills for as long as possible? When you’re finally forced to turn it on because it’s so cold there’s frost on the windows and you can see your breath inside, you may be in for an unpleasant surprise.

It’s dead. No heat. Now what?

Don’t panic just yet. There are a number of minor issues that could have contributed to your furnace not working. Before you send everybody home so they don’t get frostbite, check out the following:

1. Power Switch

This may seem obvious, but make sure your furnace is getting power. If you’re in New York City, your furnace is probably housed in tight quarters (possibly in a closet or a crawl space) and it’s not that unusual for a power switch to be accidentally turned off. Look for the switch on the side of the furnace, possibly inside a metal housing.

2. Fuses

Another power-related issue is the fuse that controls the electricity to your furnace. You may see a fuse mounted inside the metal housing with the power switch. If it looks black and burned, then a call to your NYC HVAC service company is in order so the fuse can be replaced and your system checked for underlying problems.

You should also check your building’s fuse box for any tripped circuit breakers. If you reset the circuit breaker and it trips again, then you need to call in an electrician since there may be an issue with your electrical system.

3. Vents and Intakes

Your furnace has vents for intake of fresh air and exhaust of toxic gases. Air flow through the system is essential for its efficient operation and for safety reasons. There are a number of controls in your system that can shut off the furnace if air flow is impeded. Check your chimneys and any vents that run to the outside of the building. They may be clogged with debris, leaves, or even nests from insects, birds or rodents.

4. Air Filter

Your furnace’s air filter is also an essential component that regulates air flow through the system. If it’s clogged, your furnace will probably still turn on, but there will be very little air blowing from the heat registers. This is a very easy fix, and one you can do yourself.

5. Thermostat Settings

Again, this may seem obvious, but make sure your thermostats are set correctly. Today’s programmable thermostats are great for saving energy, but not always so easy to figure out. Check your manual to make sure all thermostats are set to turn the heat on at the right time and temperature.

6. Batteries

Speaking of thermostats, when is the last time you changed the batteries? If you see a flashing “low battery” warning, or even if you don’t but you know it’s been at least 6 months, change them right away.

Next Steps:

Call in your friendly neighborhood HVAC service guy.

Obviously, if none of these things turned out to be the problem with your furnace, it’s time to call in the professionals. But there’s still no reason to panic. Especially if you have a newer gas furnace, these units are much more complicated than they used to be, and there are many other minor issues that require professional service but won’t necessarily set you back all that much.

Why worry about your furnace?

Even if you got lucky this time and figured out that your thermostat just needed new batteries, it’s still in your best interest to put in that call to your HVAC service company. After a long season of sitting unused, your furnace needs to be thoroughly cleaned and tuned up to improve efficiency and reduce your energy usage, prevent breakdowns and prolong the life of your system.

Next time, save yourself from this anxiety-provoking situation by scheduling your heating preventative maintenance before the start of the cold season. That way, you can be sure that everything is in good working order come that first frosty morning.

If you’ve been neglecting HVAC preventative maintenance, you may be surprised to find that it’s not as expensive as you thought, and can actually pay for itself in cost savings. Preventative maintenance contracts can be designed to suit the needs of your equipment, your business and your budget. Find out more from our helpful guide: HVAC Preventative Maintenance Contracts: How to Find the Right One for Your HVAC Infrastructure.
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