Solar Hot Water Pumps FAQ'SSolar hot water circulating pumps can be used for many different projects. Understanding the technical aspects of how they work can help you to troubleshoot problems or understand what is the pump for your needs.

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Solar Hot Water Pumps – FAQ’S


How does the HEAD value relate to my system?

Head is the height at which water pumps can raise liquid.

*Please bear in mind that most of our customers are dealing with an enclosed solar hot water system. One where the hot water panels are on their roof. In an enclosed system, that is one completely void of air, head becomes almost a moot point. Hence, as the saying goes, what goes up must come down.

Water in a solar hot water heating system that is coming down off the roof creates a syphoning effect on the water going up to the roof, thus effectively offsetting the head pressure.

In such cases the flow rate is normally the primary concern.

Why does an air lock occur in my system?

A blockage of the flow in a pump or pipe, caused by an air bubble. An air lock is a restriction of, or complete stoppage of liquid flow. This is caused by air trapped in a high point of a liquid-filled pipe system. Air, being less dense than the liquid, rises to any high points. When pressure is applied, instead of the liquid flowing as it normally would an air lock occurs. Simply put an air bubble reduces the flow in direct proportion to the size of the air bubble. Example: a 1/4” bubble in a 1/2” line reduces the flow by 1/2.

It is common that problems with a system are due to a trapped air bubble. To fix this problem be sure to carefully purge the air from the system. See our troubleshooting video on YouTube.

Do I have to always submerse a SUBMERSIBLE pump in water?

Submersible pumps operate in or out of water. Their waterproof housing allows them to be submersed without causing damage.

Important. Please note that dc water pumps marked as H (for high temperature rating) cannot be submersed in high temperature liquid. You must either use the pump as an external high temperature pump or a submersed low temperature pump.