In the world of home climate control, the thermostat is our trusty guide, ensuring we stay comfortable throughout the year. However, you may have come across the mysterious “EM Heat” option on your thermostat and wondered what it's all about. In this blog, we'll demystify this term, with a special focus on thermostats from Ocean Controls Limited. Understanding what “EM Heat” means can help you make more informed decisions about your heating system and energy usage.

Many modern homes are equipped with heat pump systems. These innovative devices work by transferring heat from one place to another. In heating mode, they extract heat from the outside air (even in cold weather, to a certain extent) and pump it into your home. This is an energy-efficient way to warm your living spaces. But heat pumps have their limitations.

When the outdoor temperature drops too low, the efficiency of the heat pump can decline significantly. To supplement the heat pump's performance in such extreme conditions, most heat pump systems are paired with auxiliary heat. This is often an electric resistance heater that provides an extra boost of warmth when needed.

“EM Heat” stands for “Emergency Heat.” It is directly related to the auxiliary heat source in your heating system. When you activate the “EM Heat” option on your thermostat, you are bypassing the normal operation of the heat pump and relying solely on the electric resistance heaters for warmth.

Regular heating with a heat pump involves a complex process of heat transfer and temperature regulation. The system constantly adjusts based on the indoor and outdoor temperatures to provide efficient heating. In contrast, “EM Heat” is a more straightforward, brute-force approach. It simply turns on the electric heaters at full power to quickly raise the temperature in your home. This can be useful in certain situations, but it also comes with some downsides.

During a particularly harsh winter cold snap, when the outdoor temperature dips well below the heat pump's effective operating range (usually around 20°F or lower, depending on the system), your heat pump might struggle to keep up. In such cases, turning on “EM Heat” for short periods can ensure your home stays warm. However, it's important to monitor its usage, as we'll discuss later.

If your heat pump stops working properly, perhaps due to a mechanical issue or an electrical fault, “EM Heat” can be a temporary lifesaver. It can provide immediate warmth while you wait for a professional technician to come and repair the problem. For example, if the heat pump is making strange noises or not heating at all, switching to “EM Heat” can keep your family cozy.

When the power goes out and then comes back on, sometimes the heat pump needs time to reset and resume normal operation. In the meantime, “EM Heat” can be activated to maintain a livable temperature inside the house.

Most Ocean Controls Limited thermostats have a clearly labeled “EM Heat” button or option on the control panel. It may be a physical button that you press, or it could be an option within a menu on a touchscreen thermostat. The location and design of the control may vary slightly depending on the model.

To activate “EM Heat,” simply press the appropriate button or select the option. The thermostat will usually display an indicator, such as an icon or a flashing light, to show that “EM Heat” is on. It's crucial to monitor the temperature in your home and be aware of the energy usage. Since “EM Heat” uses a lot of electricity, you don't want to leave it on for extended periods unless absolutely necessary. When the situation improves, turn off “EM Heat” to return to normal heating mode.

As mentioned earlier, “EM Heat” relies on electric resistance heaters, which consume a significant amount of electricity. Running “EM Heat” continuously can lead to a spike in your energy bills. It's advisable to use it only when truly necessary and to consider alternative heating sources, like a fireplace or portable heaters, if possible.

Ocean Controls Limited thermostats often come with energy-saving features and programmable schedules. Even when using “EM Heat,” you can take advantage of these to minimize energy waste. For example, you can lower the temperature in unoccupied rooms or set the thermostat to turn off “EM Heat” during the warmest parts of the day.