Posted: February 2, 2026
Avoiding and Addressing Mid-Winter Boiler Failures
What Are the Common Causes and How Can You Prevent a Heating Breakdown?
Nothing puts the brakes on your day like a heating system breakdown in the middle of a frigid winter day. Until you get your equipment up and running again, your home will steadily lose warmth — and it can quickly go from merely uncomfortable to truly unsafe.
In New York, Pennsylvania, Connecticut, Massachusetts, Rhode Island and Vermont, many Mirabito customers heat their homes with boiler systems. These tried and tested heating systems generate cozy warmth by transferring steam or hot water to radiators, baseboards or radiant floor systems. When a boiler is running at peak performance, it’s hard to beat for winter comfort. In this article, we’ll discuss the common causes of winter boiler failures, what to do about them and how to prevent them from occurring.
Why Do Boilers Break Down?
Today’s oil and gas boilers are built for efficiency and durability, but like any complex home system, they can occasionally face service issues. Here are some common problems that can cause a boiler to break down and what you can do about them:
- Clogged or Frozen Condensate Drain. Newer high efficient boilers have condensate drains that dispose of water created by the exhaust gases that are typically vented outside your home. These pipes can either become clogged with debris or freeze up if the boiler is in an unconditioned space, which may lead the boiler to shut down. If it is clogged, depending upon how it was installed or piped you may be able to unclog it by clearing the drain pipe. If it is frozen, you can try pouring hot water over the pipe to thaw it, but do not apply a flame to it. If either of these do not work, reach out to our service team to fix the issue.
- Fuel Run-Out. If you have an oil or propane boiler, you should check your fuel tank gauge to ensure you haven’t run out. If you’ve had a run-out, reach out to us right away for an emergency delivery.
- Low Water in a Steam Boiler. A steam boiler may shut down if it does not have enough water in it. You can check the water level on a steam boiler using the sight glass that is either on the front or side of the boiler. If the water level is low, you may be able to manually add more water by opening the valve on the main water feed pipe to the boiler, however be sure not to overfill it. However most newer steam boilers may have an automatic water feed which may require service by our service team to fix the issue.
- Low Pressure on a Hot Water Boiler. If your boiler’s pressure is below 1 PSI, it probably won’t function properly. Consult your owner’s manual to adjust the pressure, but if you’re uncertain about the process, please contact our service team to fix the issue.
- Boiler Kettling. Kettling happens when limescale causes the system to make loud noises and eventually shut down. You may need to have someone descale the boiler and replace parts if needed.
- Leaking. Leaks can happen in older boilers, and there are many potential causes, from corrosion to loose fittings. Some leaks can be repaired, but many will require a boiler replacement. If you suspect a leak, contact our service team to address the issue.
- Radiators Not Heating Up. Confirm that your radiators are fully open. If they are open but not heating up, there could be air trapped in them. You can take care of this problem by bleeding the radiators. It only takes a few minutes. Use a radiator key to open the bleed valve at the top of each radiator until water flows steadily, then close the valve.
Be Safe! If you are unsure of how to resolve any of these issues, it is highly recommended that you reach out to our service team to help fix them.
Preventing Boiler Issues Before They Start
They say an ounce of prevention is worth a pound of cure, and that’s definitely the case with home boiler problems. Two things you can do once a year to prevent the issues listed above are:
- Bleed your radiators to avoid pockets of air
- Flush your boiler of sediment by turning it off, draining until the water runs clear and refilling to the proper level. Check your owner’s manual for details.
The most important thing you can do to safeguard the health, reliability and efficiency of your boiler is to arrange annual preventive maintenance for it. And the most effective way to ensure your system gets this maintenance — plus priority service, discounted repairs and other benefits — is to enroll in one of our affordable service memberships. The Mirabito Energy Products team is here to ensure your home gets the service it needs so you stay warm all winter long!
Contact Mirabito today to enroll in a service membership or schedule service for your heating system.
