QUESTION: My outside heat pump froze up so solid, the outdoor fan was hitting the ice. What could have happened? — When the ice hits the fan
ANSWER: With the season in mind, let me start out with a little song that may help explain the situation. Frosty the Heat Pump was a very lonely soul, As he sits outside in the ice and snow Working at 20 below. Frosty the Heat Pump takes heat out of the air, Then puts it inside where it’s warm and dry. Keeping you cozy without compare. There must have been some magic in the heat transfer that day. He worked so hard that he turned to ice and began to rattle around. Frosty the Heat Pump had a defrost system that’s lame. Once the air stops moving, the process stopped grooving, Snowball is his new name. When Frosty’s covered the savings get smothered as heat transfer just stops. All we do is wear him out until his compressor just goes “pop.” Frosty the Heat Pump needs a regular clean and check. With a little love and a good refrigerant charge, you can keep him from being a wreck. Alright already, that was the worst rhyming since… the beginning of rhyming! The point is your heat pump needs regular maintenance which is made more important by the harsh weather we encounter. All air-source heat pumps go through defrost, much like your refrigerators, to rid the evaporator coil of air-restrictive ice. Air movement is heat transfer, and slowing or stopping that is both inefficient and harmful to your system. Once the ice ball is noticeable, it is usually a big deal to clear it off. We go on many calls where the outdoor coil has been in the process of making glacier ice for days without stopping. We will spend hours with hot water clearing both the inside and the outside of the unit. It must be completely clear before any accurate diagnostics can be made. You can clean this ice off yourself but the power should be off and only use water — hot or warm is fine. Due to the construction of copper and aluminum, please do not take any sharp object to the unit — ice picks come to mind. One puncture will cost hundreds of dollars and sometimes is not repairable. Leaving the unit off in above freezing weather works but usually is a long process. Once Frosty is thawed, checking refrigerant charge is the key. This may need to be done by “weighing out” which is removing the refrigerant and actually checking its weight as it compares to the outdoor unit name tag. If that is just dandy, the defrost control board and its sensors can be verified. This rather simple board samples outside air and coil surface temperatures. It also includes a run time calculation. Running as long as possible without a defrost is more efficient, but oftentimes can result in ice issues. This is adjustable but must be done with consideration to efficiency and reliability.
