Heat Pump Not Working? A Toronto Homeowner’s Troubleshooting Guide

Introduction 

Many guides will give you a generic list of things to check when your heat pump is not working. This guide is different. We will first demystify the strange behaviors of a heat pump in a Toronto winter. Then we’ll walk through the simple checks that can save you a service call. You will learn the difference between a normal operational quirk and a genuine problem.

The Defrost Cycle: Is Your Heat Pump Broken or Just Breathing?

Most likely the defrost cycle is that unsettling cloud of steam and burst of cold air. For any heat pump working in our frigid, muggy environment, this is a typical and vital activity. It doesn’t mean there’s something wrong. It’s an indication that the machine is self-adjusting.

This is what is going on. Your outside unit’s coils get even colder than the air itself to draw heat from frigid winter air. This encourages frost to grow on them, much like how it does in an ancient freezer. Unit won’t operate if this frost becomes too heavy since it inhibits ventilation. The heat pump flips itself momentarily to address this. It switches to air conditioning mode, which sends hot refrigerant gas to the outside coil to melt the ice rapidly. The melting frost will produce a large plume of steam; the compressor will hum differently; the outdoor fan will stop spinning. Usually, this procedure runs five to ten minutes long. Unit finishes the cycle and warm air returns, everything is OK.

Your First 3 Checks Before Making a Panic Call

Before you assume the worst, always check the three most common culprits. These simple steps take less than five minutes and solve a surprising number of service calls where a heat pump is not working. A systematic check here can save you time and money.

Check the Thermostat Settings

It seems evident, but it occurs frequently. One of the people in the house could have accidentally turned the system to Cool or Fan. Only. Check your thermostat to make sure it is set to Heat. For it to turn on, the set temperature must be higher than the current room temperature. Check to ensure a schedule has not taken precedence over your manual setting if you own a smart thermostat such as Google Nest.

Inspect the Air Filter

The main adversary of every forced air system is a dirty air filter. It constricts your heat pump, therefore compromising airflow and driving it to operate considerably more difficultly. At worst, it might make the system overheat and switch off. Throughout the heating season, you ought to inspect your filter monthly. Pull it out. It is time to replace it if you cannot see light through it.

Verify the Power

There are two different circuit breakers for heat pumps: one for the indoor unit, which is called the air handler, and one for the outdoor unit, which is called the condenser. Locate your electrical panel and confirm that both breakers are switched on. Occasionally, a breaker might pass without seeming to be one. Turn it off then on again to double check. Look as well for an emergency shut off switch, usually found close to your interior furnace or air handler and resembling a typical light switch.

Is the Outdoor Unit a Block of Ice?

On the outdoor unit, a thin coating of white frost is quite normal. Not a dense, solid ice block enfolding the entire machine is. Unit is a clear indicator of defrost cycle failure or inability to keep up with circumstances if it seems like a modern ice sculpture.

A few factors might contribute to this. First, check that there is nothing obstructing airflow around the unit. In a two-foot radius, clear away any fallen leaves, trash, or heavy snow drifts. Checkup too. A frequently occurring issue in Toronto is a leaking eavestrough that drips water straight onto the unit, where it quickly freezes. If the unit is still a block of ice but the area is clear, you probably have a mechanical problem such as malfunctioning reversing valve or a defective sensor. Do not use a sharp object to try to remove the ice. One might puncture a coil and set off a costly refrigerant leak.

When to Call a Professional HVAC Technician

If you have tried the basic fixes and your heat pump still isn’t running, it’s time to contact a qualified expert. Do not attempt to open the panels and self-diagnose the problem. You are managing high-pressure refrigerant and high voltage electricity.

If you observe any of these symptoms, call an expert right away:

• Unit makes metallic screeching, grinding, or banging sounds as well as loud noises.
• The circuit breaker trips again right after you reset it.
• The system is always running, but it blows cool or warm air (and you said you’ve checked it’s not in a defrost cycle).

Tell the dispatcher everything you can when you call. Tell them the unit’s brand, perhaps Mitsubishi or Bosch. Specify the symptoms unambiguously. Let them know the troubleshooting actions you have so far followed. Technicians use this knowledge to plan and perhaps achieve a quicker diagnosis. Since they need expertise, it’s usually wise to pick a contractor with demonstrated experience in cold-climate heat pumps.

Stay Warm and Informed

The heat pump in your house is a very complicated appliance. A stress-free heating season starts with knowledge of its typical winter behavior. Most of the time, the weird noises and sights are only indicators of a good system changing to fit the chill. Understanding these indicators and doing simple tests will help you confidently manage most circumstances.

Tell us in the comments below the one thing you have discovered about your heat pump that most shocked you.