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Welcome to Grissom Heat & Air, your go-to source for top-notch HVAC services in Knoxville, TN. We specialize in various HVAC solutions, with particular expertise in heat pump installation, maintenance, and repair. Heat pumps are an increasingly popular choice for modern homeowners, mainly due to their impressive versatility – they can both heat and cool your home with the simple flip of a switch. But like any complex appliance, heat pumps are not without their quirks.

One issue that we frequently encounter is the heat pump’s inability to switch effectively between its heating and cooling modes. This can be quite frustrating and, in some cases, indicative of a larger problem with your heat pump system. Instead of digging through online tutorials and attempting a risky DIY fix that could worsen the issue, why not educate yourself first? In this comprehensive guide, we’ll delve into the ins and outs of common heat pump problems, particularly those associated with mode switching, and we’ll discuss why professional intervention is always the best course of action.

How Do Heat Pumps Work? Versatility Explained

Heat Pump Systems in Knoxville, TN



The Mechanics of a Heat Pump

A heat pump is a highly versatile system that serves both heating and cooling purposes by reversing the direction of the refrigerant flow. It uses a crucial component called a reversing valve to change between heating and cooling modes.

Importance of Timely repairs

Timely heat pump repair is essential for preventing minor issues from escalating into major problems that could severely impair your system. It’s always better to resolve any problems as soon as they are detected, and the sooner you call for professional help, the better.

The Reversing Valve: A critical Component

The Role of the Reversing Valve

Your heat pump system’s reversing valve enables the appliance to switch between heating and cooling modes. It changes the direction of the refrigerant flow, allowing it to remove heat from your home in the summer, while introducing heat into your home in the winter.

Reversing Valve Failures

The wiring of the reversing valve can wear down over time or the valve itself can fail. Additionally, a refrigerant leak near the reversing valve could block its operation. This often results in the valve getting stuck in a single mode position-either heating or cooling.

Thermostat Concerns

The Communication Hub

The thermostat acts as the command center for your heat pump system. If you switch it from heating to cooling, it should relay that command to your heat pump. Sometimes however, this connection gets interrupted or the thermostat itself may not be calibrated correctly.

Upgrading Older Thermostats

If you have a thermostat that’s over a decade old, upgrading it is highly advisable. Newer models are more reliable and feature-rich, making it easier to control your heat pump system more effectively, even from your phone or tablet.

Other Signs Your Heat Pump May Need Attention

  • Screeching Noises – These can be caused by worn or unlubricated parts.
  • Unusual Odors – It is not uncommon for dirty coils or stagnant water in the condensate pans to create unusual and unpleasant odors.
  • Short Cycling – This may indicate the presence of a refrigerant leak coil issue, or a faulty thermostat.

When DIY Won’t Cut It: The Importance of Professional Repair

Why Choose a Professional for Repairs?

Heat pumps, while designed to be highly efficient, are not always invincible. At some point, every heat pump will require professional attention. When your heating system develops an issue that a simple tune-up won’t solve, the safest and most effective approach is to seek professional assistance from our qualified team at Grissom Heat & Air.


In summary, heat pumps are wonderfully versatile systems that can bring great convenience and comfort to our homes. However, this versatility can sometimes act as a double-edged sword, leading to issues when switching between heating and cooling modes. While some of these issues might seem manageable with a bit of DIY tinkering, the risks associated with improper handing far outweigh the potential benefits. Electrical issues, refrigerant leaks, and reversing valve malfunctions are not simple to repair and require the skill and expertise that only professional heating and cooling technicians can provide.

For residents in and around Knoxville, Grissom Heat & Air stands as a reliable and efficient solution for all of your heat pump repair needs. We’re committed to diagnosing and rectifying any issues your system many have, ensuring its longevity and its optimal performance. If you encounter any problems with your heating or cooling systems, remember that timely, professional repair is the safest and most effective route to take. Here at Grissom Heat & Air, your comfort and peace of mind are our top priorities.

Choose the Very Best

In a world full of choices, make the one that offers long-lasting peace of mind. If you’re a resident of Knoxville or the surrounding areas, don’t settle for anything less than the expertise and reliability that Grissom Heat & Air can offer.

For over 39 years, Grissom Heat & Air has been a leading provider of reliable HVAC systems in Knoxville, TN, dedicated to ensuring customer comfort. Our expert technicians offer an array of residential and commercial services, including maintenance and repair, inspections, and specialized services like heat pump repair. We also provide comprehensive AC services, from troubleshooting and repair to new installations. With a focus on quality and efficiency, we use state-of-the-art tools and procedures. We offer timely consultations and estimates to help you choose the right HVAC solutions for your situation. Our consistent commitment to excellent service has made us a top choice in the industry for over three decades.

For more information about the products and services we provide, contact us via our website or give us a call at 865-225-9207. We look forward to serving you!