This Winter Was the Test Your Home’s Heating System Did Not Ask For

Philadelphia just lived through something brutal. Thirteen consecutive days of below-freezing temperatures. Wind chills that made Roosevelt Boulevard feel like Antarctica. The Delaware River froze. Car batteries died in driveways across Bensalem. And heating systems across Northeast Philadelphia revealed exactly what they are made of.

If your furnace, boiler, or heat pump kept your home comfortable through the past two weeks, it passed a test it never signed up for. But passing does not mean nothing happened. Components wore down. Parts that were running at 90% are now running at 70%. Weaknesses that would have taken years to surface got exposed in days.

The city declared an Enhanced Code Blue. Schools closed because boilers failed. At Farrell Elementary in Northeast Philadelphia, middle schoolers sat in classrooms wearing coats because only one boiler was working. Teachers brought personal space heaters from home. One teacher who wears shorts every day finally broke down and put on pants.

This happened in buildings with professional maintenance staff and regular inspections. Now ask yourself: when was the last time anyone really looked at the heating system in your house?

You know winter hit different when everybody on the block is standing outside in a hoodie talking about how nice it feels. After days of single digits and wind chills that made Cottman Avenue unbearable, 32 degrees genuinely feels comfortable. That collective sigh of relief you heard across Mayfair and Torresdale was real.

But that relief comes with a catch.

When your system was running nonstop for days, it was working harder than it does in a typical January. Every component, from the blower motor to the ignition system to the circulator pump, was under sustained load. Some homeowners reported their furnaces running continuously for 72 hours straight. Others watched their thermostats display temperatures that never climbed above 55 no matter how long the system ran.

The city received 1,352 complaints about properties without proper heat in 2025 alone. More than 40% of those complaints resulted in violations. And that was before this cold snap pushed systems past their limits.

Now that temperatures have climbed back into the 30s, your system is transitioning from survival mode back to normal operation. That transition is when problems show up.

Most homeowners think about heating problems in simple terms: the system works or it does not. But extreme cold creates a middle ground where systems technically function but accumulate stress that shortens their lifespan or sets up future failures.

During prolonged cold, your heating system experiences longer run cycles, which means more wear on motors and moving parts. It deals with greater temperature differentials between indoor and outdoor air, which strains heat exchangers and ductwork. It faces increased demand on fuel delivery systems, whether that is gas valves, oil burners, or electrical components. And it has to push heated air or water through a home that is losing heat faster than normal through walls, windows, and that drafty back door nobody ever fixed.

The result is not always dramatic failure. Sometimes it is a part that is now running at 80% instead of 100%, or a component that will last two more years instead of five. The damage is real, but it is often invisible until something finally gives.

Think of it like running a marathon you did not train for. You might cross the finish line, but your body will remind you for weeks that you pushed too hard.

A radio DJ in South Philadelphia described what thousands of homeowners across the region experienced this month. His rowhome lost its neighboring house to demolition years ago, which exposed the party wall to the elements. During this cold snap, his forced-air furnace could not keep up.

His words capture what HVAC companies heard from callers all week: “The heater continuously goes through its cycles to the point where it’s just forcing cold air because it runs out of time to heat anything up. It got to the point where I woke up and it was 45 degrees. I thought, I’m turning it off and letting it ride out until we get to normal temperatures.”

He abandoned his central heating and shrank his life to one room with a space heater.

This is what happens when demand exceeds capacity. The furnace fires up, heats the air, pushes it through the ducts. But before the house reaches temperature, the system cycles off. Then it fires again. And again. Eventually, the furnace cannot produce heat fast enough, and the air coming out of the vents feels lukewarm or cold.

The question every homeowner needs to answer: Is this because the weather was extreme, or because something in my system is failing?

Signs your furnace is struggling against the cold (not broken):

The filter has not been changed in months. The home has poor insulation, single-pane windows, or significant air leaks. The furnace is properly sized for normal conditions but fighting impossible ones. Once temperatures moderate, the system catches up and maintains temperature without issue.

Signs your furnace is actually failing:

Strange noises that started during the cold snap and have not stopped. A burning smell when the system runs. Short cycling where the furnace turns on and off every few minutes. The system is more than 15 years old and has never had professional maintenance. Temperatures dropped inside even when outdoor temps climbed back above 25 degrees.

Hot water and steam boilers have a reputation for reliability that furnaces cannot match. That cast iron radiator in the front bedroom has been warming the house since before you were born. The boiler in the basement fires up, the pipes knock a little, and within an hour the house is comfortable. That is how it has always worked.

Until this month.

Boiler systems across Philadelphia are showing strain in ways homeowners have never seen. Radiators that are hot on top but stone cold on the bottom, which means sludge buildup is blocking water flow. Second floors that will not heat no matter how long the system runs, which means pressure is too low to push water upstairs. Circulator pumps humming along but not actually moving anything. Zone valves frozen in closed position after decades of reliable operation.

The problem with boiler longevity is that it creates a false sense of security. Components wear gradually. The circulator pump that moved water efficiently in 2010 might be struggling in 2026. The expansion tank that maintained proper pressure might be waterlogged. These problems develop slowly over years, then reveal themselves all at once during extreme demand.

Philadelphia has a significant number of homes with steam radiators, a heating method that most younger homeowners do not understand at all. Steam systems rely on gravity and air vents rather than pumps and pressure. When the little air vent on the side of a steam radiator fails, that radiator stops heating. When multiple vents fail, rooms go cold while others stay warm. Many homeowners do not even know these vents exist, let alone that they need periodic replacement.

Hot water system warning signs:

Pressure gauge reading below 12 PSI when cold (should be 12 to 15). Radiators cold on one floor but hot on others. Boiler running but the pipes coming out of it staying cool to the touch. Expansion tank that feels completely full of water when you tap it (it should feel partially empty).

Steam system warning signs:

Radiator air vents hissing constantly or not hissing at all. Banging and clanging in pipes that sounds like someone hitting them with a hammer. Wildly uneven heating from room to room. Water spurting from radiator vents instead of releasing air.

Heat pumps are efficient, quiet, and increasingly popular across Bucks County and the surrounding suburbs. The salesperson probably explained that they can heat and cool your home with one system. What they may not have emphasized is that performance drops significantly when outdoor temperatures fall below 25 degrees.

During the recent cold snap, heat pumps across the region hit their practical limits.

Most air-source heat pumps lose efficiency below 40 degrees and struggle significantly below 25 degrees. When temperatures dropped into the single digits for days at a time, heat pumps had to rely heavily on backup heat, which is typically electric resistance heating. That backup heat works, but it is expensive. Homeowners with heat pumps saw their electric bills spike dramatically, some reporting bills double or triple their normal winter usage.

The physics are straightforward. Heat pumps do not create heat. They move it. The outdoor unit extracts heat from the outside air and transfers it indoors. When outdoor air is 40 degrees, there is plenty of heat to extract. When outdoor air is 5 degrees, the system has to work exponentially harder to find heat that is barely there.

If you have a heat pump and noticed your home struggling to maintain temperature, or if your electric bill this month looks like a mistake, that is not necessarily a malfunction. That is physics asserting itself.

The question is whether your system has adequate backup heat, whether that backup is engaging when it should, and whether the backup heat was sized to actually carry the load during extreme cold.

Ductless mini-split systems have become the go-to solution for older rowhomes in Mayfair, Holmesburg, and Torresdale where adding traditional ductwork is impractical or impossible. These systems mount on the wall, connect to an outdoor unit with small refrigerant lines, and provide heating and cooling without tearing apart your house.

As a Mitsubishi Diamond Contractor, R&R Mechanical has installed hundreds of these systems across the region. This cold snap revealed important truths about their limitations.

Homeowners are reporting outdoor units covered in frost that does not clear between defrost cycles. Indoor units blowing air that feels barely warm. Rooms that were always comfortable now running ten degrees colder than the rest of the house. Systems cycling into defrost mode so frequently that they never get a chance to actually heat.

Here is what most people do not understand about ductless systems: they are heat pumps. Everything that applies to standard heat pumps applies to mini-splits. They move heat rather than create it. When outdoor temperatures drop into the single digits, standard mini-split units lose capacity fast.

Not all mini-splits are created equal. Standard units lose significant efficiency below 25 degrees. Mitsubishi Hyper-Heating (H2i) units maintain output down to negative 13 degrees. If you bought the least expensive option, or if you inherited whatever the previous owner installed, you may have a system designed for mild winters trying to handle Philadelphia’s worst cold snap in years.

What you can do right now:

Clear snow and debris from the outdoor unit. Maintain at least two feet of clearance on all sides so air can flow properly. Check that nothing is blocking airflow to the indoor unit, including furniture or curtains. Set your temperature a few degrees higher than normal to help the system maintain output. If thick ice has built up on the outdoor unit, turn the system off and call for service. Do not try to chip the ice off yourself because you can damage the coils.

When to call for help:

Ice that does not clear after running the system for an hour in milder temperatures. Indoor unit blowing cold air consistently instead of warm. System cycling on and off every few minutes without ever reaching temperature. Unusual grinding, clicking, or buzzing sounds from the outdoor unit.

Here is something most homeowners do not realize: heating system failures often happen AFTER extreme cold, not during it.

During the worst of the cold, your system was running almost continuously. Components that were already weakened or worn were kept warm by constant operation. The thermal expansion and contraction cycles that stress metal parts were happening, but the system never fully cooled down between cycles. Everything stayed hot and stayed moving.

Now that temperatures have moderated, your system is cycling normally again. It runs, shuts off, cools down, then fires back up. That cycling creates stress on components that were already pushed to their limits. A heat exchanger that developed a hairline crack during the cold snap might not fail until weeks later when repeated heating and cooling causes that crack to spread. An igniter that was degraded by extended use might work fine for another week before it finally gives out on the coldest night in February.

This is why HVAC contractors often see a spike in no-heat calls not during extreme cold, but in the days and weeks after. Systems that held together under extreme stress finally let go when conditions return to normal.

The two weeks after a major cold snap are statistically the most likely time for a heating failure. Not because the weather is worst, but because stressed components are cycling through temperature changes they can no longer handle.

If your heating system struggled during the cold snap, made noises it never made before, ran longer than usual to reach temperature, or behaved differently than in previous winters, those observations matter. Do not assume the danger has passed just because temperatures improved. The opposite might be true.

Heating systems do not exist in a vacuum. They exist inside homes, and the homes in Northeast Philadelphia and Bensalem have characteristics that affect how heating systems perform under stress.

The rowhomes that line streets from Mayfair to Torresdale share walls with neighbors, which helps with heat retention but also means heating systems are often crammed into tight basement spaces with limited airflow and awkward access. Older homes frequently have a mix of system generations, with a newer furnace connected to decades-old ductwork, or a modern boiler feeding radiators that were installed before your parents were born.

Many homes in the area were built between the 1940s and 1970s, with insulation standards that do not match modern efficiency expectations. A furnace in a well-insulated 2010 build might run 40% of the time during a cold snap. The same furnace in a drafty 1950s rowhome with original windows might run 80% of the time or more, burning through fuel and accumulating wear at double the rate.

The housing stock also includes a significant number of homes with radiant floor heating from the Levittown era, systems that used copper tubing embedded in concrete slabs. This was cutting-edge technology in the 1950s. By the 1980s, much of that copper started failing. Homeowners today often inherit these systems patched, supplemented with other heat sources, or abandoned entirely with the tubing still buried in the floor.

Philadelphia also has thousands of homes with steam heat, a technology that peaked in popularity before World War II. Steam systems require different maintenance, different troubleshooting, and different expertise than modern forced-air or hot water systems. Finding contractors who truly understand steam heat becomes harder every year.

These factors compound the stress that extreme cold places on heating equipment. A system that would perform fine in a newer, tighter home might struggle in a century-old rowhome with single-pane windows and no insulation in the walls.

If your heating system struggled during the recent cold, you have options. None of them require panic, but all of them require honesty about what you observed and what it might mean.

Path One: Tune and Stabilize

If your system made it through but seemed to work harder than usual, a professional tune-up can identify and address minor issues before they become major problems. This includes cleaning components that accumulated extra wear, checking electrical connections that may have loosened under thermal stress, testing safety controls to make sure they still function properly, and measuring system performance against manufacturer specifications.

For most systems that are under 10 years old and have been reasonably maintained, this is often the right first step. A maintenance visit typically runs between $120 and $149 and can extend the life of your equipment significantly.

Path Two: Reinforce Weak Points

If your system showed specific problems during the cold snap, such as a zone that never reached temperature, a blower that made noise it never made before, a boiler that took forever to recover, or a mini-split that could not keep one room comfortable, targeted repairs can address those weak points.

This is not about replacing the whole system. It is about strengthening the components that revealed themselves under stress. Sometimes a circulator pump replacement, a blower motor upgrade, or a control board repair can add years of reliable life to an otherwise solid system. Sometimes a single zone valve or air vent is the difference between a system that struggles and one that performs.

Path Three: Plan Replacement Before the Next Test

If your system is older than 15 years, struggled significantly during the cold snap, required emergency repairs, or has needed multiple repairs in recent years, replacement might make more sense than continued investment in aging equipment.

This does not mean you need to replace it tomorrow. But planning a replacement for spring or summer, when contractors have more availability and you have more time to research options, beats scrambling during the next cold snap when everyone in the region needs help at once.

Replacement done on your timeline costs less than replacement done on an emergency timeline. You get to choose the equipment instead of taking whatever is available. You can take advantage of rebates and tax credits that require planning ahead. And you enter next winter knowing your system can handle whatever Philadelphia throws at it.

The worst of this winter’s cold is probably behind us, but February and March in Philadelphia can still deliver surprises. Lake-effect snow, late-season cold snaps, and those raw rainy weeks when nothing ever quite dries out are all still on the table.

Your heating system has already proven it can handle extreme conditions, or it has shown you exactly where its limits are. Either way, you know more now than you did two weeks ago.

R&R Mechanical has been helping homeowners across Northeast Philadelphia, Bensalem, and the surrounding communities keep their homes comfortable through winters like this one for years. We understand the specific challenges of heating systems in this area because we live here too. We know the rowhomes, the basements, the older boilers, the steam radiators, and the ductless systems that have become essential for so many local families.

We specialize in systems that other contractors do not always understand. Church boilers that heat historic buildings. Steam radiators in century-old rowhomes. Ductless mini-splits in tight spaces where nothing else fits. If your system is unusual, old, or just different from what most companies see every day, that is exactly the kind of work we do.

If you noticed anything concerning about your heating system during the recent cold, or if you just want peace of mind that everything is operating as it should, we are here to help. We offer remote troubleshooting via text, Zoom, and FaceTime for quick questions that might not need an in-person visit. We monitor text messages around the clock and schedule next-day service when you need someone on-site.

The goal is not to sell you something. The goal is to make sure your heating system is ready for whatever the rest of this winter and next winter bring. Because if this cold snap taught us anything, it is that the test comes whether you are ready or not.