Is Your Solar Thermal Working Optimally?

solar-thermal_water_heating (2) From Steve Ruby, Owner of Aqua Care Solar. Steve has 30 years experience in Solar Thermal installation and service:

How to know when a Solar Heating System is working:

Since the goal is to heat something, have a look at the following:

  • If the system uses air to move heat, is hot air coming through or from the duct?
  • If the system uses water to move heat, is the tank or heated object hotter than the surrounding temperature? Solar storage tanks should be hot at the end of a clear day – assuming no large amount of heat has been withdrawn.
  • If you have a controller with a read out, it will tell you with a few pushes of a button. A blank display is a bad sign.
  • Small pumps - when running - are normally on the lower end of hot. A pump that is scalding hot - so hot that the paint is about to peel off - is not circulating and needs maintenance.
  • Check for heat flow. Pipe temperatures can be tested (or felt) to check for heat flow. Any pipe could be very hot so use caution when touching one. Antifreeze systems that loose pressure can and will become air locked. The pump(s) will run and seem to be working (hot and humming) but the tank will be cold. A pipe attached to a running air locked or stuck pump will be hot, so don’t be fooled. Feel a pipe up stream, or below, or some distance away from a pump that is running for accurate pipe temperature. The line could be air locked, or the pump could be stuck. No heat flow in a Drainback type system might indicate low water or a bad pump in the system.

Antifreeze systems need 20 lbs pressure or more to run correctly. Old gauges can become stuck and/or may not be trustworthy. If the pressure is low or never changes, the system needs attention.

Many Drainback type systems need water several times a year. To check water level, look for a sight glass or other indicator. Turn the system off and wait 5 minutes or more, for the fluid to drain back to the reservoir. Add water to the full line. If there is no full line or you are in over your head…

Call Aqua Care Solar for a complete solar thermal analysis to make sure your system is working at its best.