What are long-term maintenance costs for ductless minisplits?
bobbomax
| Posted in Mechanicals on
I’m not concerned about annual clean-the-filters type maintenance, but more about “What if a power surge blows a mother board?” type issues. My sister has had that happen twice, although it may be partially due to a poorly grounded electrical system. Other issues might be refrigerant leak or motor failure.
Does anyone have the kind of long-term, multi-installation experience needed to address this type of issue?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Some people take out insurance against things like power surges and lighting damage. This type of damage isn't unique to heat pumps- it happens to mod-cons & smart pumps and condensing gas furnaces too. If the power quality in the neighborhood is egregiously bad there are folks willing to soak heat pump owners for the cost of some amount of circuit protection hardware. It's rarely "worth it", but might be in your sister's case, depending on whether the exact cause of the damage can be determined.
Refrigerant leaks should basically NEVER happen if it was installed correctly.
Motor failures are rare. Variable refrigerant valve failures can and do happen, but that too is rare and becoming rarer. A mini-split system's failure modes aren't really any different or more common than those of a ducted split system. Buying decent name brand equipment and getting it installed by competent contractors is really the first line of defense against high risk of failure.
The NEEA consortium of utilities has been tracking thousands of mini-split installations for years, and may have published data on failure prevalence somewhere on line. You may have to do a lot of digging on their website(s) to find it though.
http://neea.org/initiatives/residential/ductless-heat-pumps
Thanks, Dana. Didn't find anything on the site, so I emailed one of the staff.
I've lost two fan motors due to bad bearings on a Mr. Slim 18,000 BTU external unit since installation in 2009. This is apparently a truly freak occurrence, as I've only read of one other such failure after repeated searching, and the service manager at my HVAC says he's never heard of any.
That's one hadn't heard before. I have multiple relatives in the pacific northwest heating their houses with the FE18NA for nearly that long, and another since 2012, with ZERO reported failures.
A friend's deep energy retrofit project in MA has been using three FE18 (one per floor) since October 2012, with no failures.