Solar Water Heater Maintenance

Just three years ago, solar water heating growth in commercial buildings was poised to grow by 20% per year, according to a report from research and consulting firm AltaTerra Research. Even the White House has joined the craze by utilizing a rooftop solar water heater – but have you?

If so, you should abide by some basic operations and maintenance principles, recommends Andy Walker, principal engineer at NREL and author of Solar Water Heating for the National Institute of Buildings Sciences’ Whole Building Design Guide.

O&M for your system is similar to that required of any hydronic heating loop and may be provided by site staff. Experts can be called in if anything fails, he adds.

Regularly scheduled maintenance should include:

• Checking the solar collectors and frames for damage
• Noting broken or leaking tubes for replacement
• Ensuring valves are in proper positions
• Inspecting pipe insulation to minimize losses and maintain freeze protection
• Checking mounting connectors for tightness and repairing bent or blemished ones
• Removing vegetation growth that may be shading the array
• Cleaning the array with water or mild detergent without using brushes, solvents, or abrasives
• Examining plumbing for signs of rust and corrosion
• Flushing the potable water storage tank to remove sediment
• Documenting all activities in a workbook that is available to personnel.

Additional maintenance can include restoring temperature sensors that have been disconnected, replacing pump capacitors and motors, repairing leaks or damage from freezing, and fixing glass broken by vandalism or environmental factors, the report reads.

At some point – typically in excess of 10 years – the storage tank may need to be replaced, it adds. But after enjoying 10 years of free hot water, that cost is just a tall glass of lemonade.