How does the defrost cycle work on Grant Aerona heat pumps? October 23, 2024 The defrost cycle on a heat pump is designed to prevent the coils from freezing over. The coils are located outside, so they are exposed to the elements and can easily turn into a block of ice. When this happens, it prevents the heat pump from working properly and can cause damage to the unit. You might be wondering how this defrost cycle works. Our heating engineers answer in this blog post. Need help with your heat pump? Call Clean Heat Solutions at 07391473964 or email info@cleanheatingsolutionskent.co.uk, our heating engineers will be with you shortly. What is a Defrost Cycle? The defrost cycle is a critical function in Grant Aerona heat pumps, designed to maintain optimal performance during colder months. This process prevents ice buildup on the evaporator coil, which can significantly impair the heat pump's efficiency. How does the defrost cycle work on a Grant Aerona heat pump? Grant Aerona air source heat pumps utilise a highly sophisticated control system that continuously monitors and detects any ice formation on the evaporator coil. Ice accumulation is a natural occurrence during colder weather, and when the system identifies frost building up, it automatically initiates a carefully orchestrated defrost cycle through a precise sequence of operations. Fan Deactivation Initially, the outdoor unit's fan ceases operation, which is essential to prevent frigid air from circulating over the coil. This step helps minimise additional ice formation whilst the defrosting process begins. Refrigerant Flow Reversal The heat pump cleverly switches to cooling mode by activating the reversing valve, which redirects the flow of refrigerant through the system. This ingenious reversal sends warm refrigerant through the outdoor coil, effectively melting any accumulated ice. The process is rather like running your freezer in reverse. Heat Utilisation During the defrost cycle, the system cleverly draws heat from the property's heating system to assist in the ice-melting process. Whilst this temporarily reduces the heat output to your home, it's a necessary and efficient way to maintain system performance. Some models may utilise a backup heating element to supplement heating during this phase. Cycle Completion Once the control system determines that all ice has been cleared from the evaporator coil, the outdoor fan recommences operation, and the heat pump smoothly transitions back to its normal heating mode. The entire process typically takes between 3-10 minutes, depending on the severity of ice accumulation and ambient temperature. This sophisticated defrosting mechanism ensures optimal performance throughout the heating season, particularly during the challenging British winter months when temperatures frequently hover around freezing. Impact on Heating System While the defrost cycle is active, the heat pump temporarily ceases to supply heat to the building. This interruption typically lasts only a few minutes and doesn't significantly affect indoor temperatures due to the thermal mass of the building and heating system. Frequently Asked Questions Why does the defrost cycle occur? The defrost cycle occurs when condensation on the evaporator coil freezes in low temperatures. The heat pump control system detects this ice formation and initiates the defrost cycle to melt the ice, ensuring efficient operation of the heat pump. How often does the defrost cycle happen? The frequency of the defrost cycle depends on external temperatures. It is more common in winter months when temperatures are below 0°C. The exact frequency can vary based on local climate conditions and the specific heat pump model. Does the defrost cycle affect my heating? The defrost cycle temporarily stops the heat supply to your heating system. However, this typically lasts only a few minutes and does not significantly affect the building temperature. The brief interruption is necessary to maintain long-term efficiency of the heat pump. Can I manually initiate the defrost cycle? No, you cannot manually initiate the defrost cycle. The process is automatically controlled by the heat pump's control system, which initiates the cycle when necessary based on its sensors and programmed algorithms. How to know if your heat pump is damaged? If your heat pump isn't providing enough heat or if it's making strange noises, it may be time to replace it. Check the manufacturer's recommendations to see how often you should replace your heat pump. If you see any of the signs, contact professional heating engineers immediately. If you reside in Southampton, Sussex, Portsmouth, or Hampshire, get the services of our trained heating engineers at Clean Heat Solutions. Call us at 07391473964 or send us a message using our contact form and we'll be happy to help. How can I ensure my heat pump operates efficiently during winter? To ensure efficient operation during winter: Keep all external doors and windows closed to maintain indoor temperature Consider adjusting thermostat timings to prevent prolonged periods without heat production Ensure regular maintenance is carried out, including checks for debris on the air inlet grill and evaporator Have the system serviced annually by a competent heating engineer