The unfortunate maintenance item would be, if you have a closed loop piping system and it should develop a leak. You might have to ultimately dig up and expose the pipe and repair the leak. That is a rare thing if it has not been installed correctly. You could compare it to the maintenance on your refrigerator, because it has the same working components in there. So, you might consider how often you have to maintain your refrigerator versus the gas furnace. For example, like a refrigerator, the heat pump has a compressor and similar components, so those are the only things that might need repair over its life cycle. Generally speaking, a heat pump is expected to last about 15-20 years before it needs any major repair or replacement.
