Solar hot water systems have been in existence for 40 years or more. These systems had historic problems of freezing and panel failures from UV breakdown. Technology has improved and many of today’s systems do not circulate the water from the storage tank to the roof. Rather, a non-freezing mixture of glycol and water is heated in the roof panels and the hot fluid transfers its heat to water in the storage tank via a heat exchanger. In many systems, the storage tank also serves as a backup water heater for nights and cloudy days. There is a recirculating pump that keeps the fluid moving through the panels and piping. he roof.
Recommended Maintenance: Like many systems that handle the flow of water, the maintenance of the system depends upon the quality of the water supplied to it. In areas where the main source of potable water is wells, either municipal or private, the water is likely to have a significant mineral content. At least once a year, the primary storage tank/heater should be drained by connecting a hose to the bib on the tank. Be sure to cut off the power to the recirculating pump. Failure to do this will result in the pump overheating and failing because there is no fluid passing through it to cool it. If the tank has a gas or electrical back up, be sure to turn off the gas or throw the breaker marked: Water Heater. Drain the tank completely into an area that can accept hot water (not a landscaped area). When the tank is completely drained, refill it and turn the gas or electricity and the recirculating pump back on.
Because of the high heat loads that the glycol solution is subjected to, it will eventually break down and the system will have to be recharged. The recharging must be performed by a qualified technician. The glycol solution should be tested annually, in late fall.
Also, on an annual basis, wash and inspect the collector panels on the roof. If the roof is a tile roof, it is recommended that the inspection be conducted with binoculars from a ladder. Do not walk on the tile (it is likely to break). Look for any cracks in the panel surface and leaks in the piping. If either are found, it is recommended that a professional service contractor be called in for repairs. Clean the panels when they are cool, such as during the early morning.
Stay tuned for the next maintenance item to complete on your Green Home!
* This blog contains items that are guidelines to follow. Advanced prototype and limited production components are not considered. If any conflicts exist between these guidelines, and those set forth in the manufacturer’s literature, the manufacturer’s maintenance instructions shall take precedence.
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