Safety and Maintenance
Properly installed solar water heating systems require minimal maintenance. Freezing and over-heating are the biggest hazards, so it is important for you to understand how your system addresses those possibilities. If your system uses a heat transfer fluid (usually food –grade glycol) you will need to check the ph balancer once in a while. Glycol that has been over-heated can become acidic and eventually can cause pin-holes in the copper coils. Pin holes and pressurize glycol are not a good combination, so get your installer to show you how to check your system and do so every year or two (or according to the recommendation).
Solar water heater collectors are much more tolerant of partial and moving shadows than solar electric systems, but an annual hose down in dirty environments is a good idea.