One of the downsides of air source heat pumps is that they are very attractive to mice. Unlike geothermal heat pumps or furnaces which live in the basement of the building, air source heat pumps are outside, it is nice and warm inside the heat pump itself, and it is the idle safe spot for mice make a winter home.
Unfortunately, the mice are pretty messy and leave their eaten acorns inside the heat pump. Additionally, a recent change in the insulation of control wiring to a corn based product means that mice now think that the wires are a convenient and tasty food source. Having mice eat wire insulation leads to a lot of electronic problems and operation issues.
The mouse poop and urine is also a problem as they will ruin components after several months of exposure – so a heat pump may run fine during winter and then a computer board will fail in the summer due to corrosion from the urine of nesting mice from the previous winter.
The mouse population is affected by how harsh the winter weather is, the supply of acorns, and how many folks have inviting heat pumps outside. The best course of action is to block off the access holes of the heat pump with steel wool, thumb gum (a thick moldable sealant), and moth balls.
Please visit our preventative maintenance page for info on our rodent efforts – usually we try to block off the holes in the unit with steel wool, moth balls, etc.
Our goal is to be Martha’s Vineyard’s premier plumbing and HVAC shop – we appreciate the opportunity to help you fight off hungry rodents that damage your equipment!