Solar heating systems are growing in popularity among pool owners.
Thermal systems, where water is circulated through panels on the
roof using the pool’s pump, especially have made inroads in
Here is a brief explanation of how thermal systems work and some
typical problems you may encounter.
Over the years, solar panels and coils have been composed of a
variety of materials, primarily copper, rubber or plastic. Today,
copper has become rare because of its cost and tendency to corrode.
Plastic dominates an overwhelming portion of the market.
There are a variety of plastic panel configurations. Basically, the
system involves two large tubes that frame a series of smaller
perpendicular ones through which the water flows.
To calculate the number of square feet of solar panels needed, many
experts simply match the square footage of the surface of the pool.
If the roof faces south or west, however, they may use less.
The majority of installations are done atop the roof. If it is too
steep or shady, however, an independent structure must be built to
accommodate the panels.
Once on the roof, the panels can be attached with a variety of
hardware. Most drill through the roof’s tiles/shingles to
hold the brackets in place and then inject a UV-protected silicon
into every hole. The silicon helps deter leaks, and the brackets
keep the panels in place. To guard against the wind, the panels are
strapped down. And, adjustable header clips are attached to the
tops and bottoms of the panels.
Then, the panels are plumbed into the pool’s circulation
system. This step may vary, depending on the manufacturer and the
distance of the pool to the house. Lastly, the system is automated
via a control pad. Sensors on the rooftop panel and at the
controller monitor the temperature of the water in the tubing and
in the pool, so adjustments can be made accordingly.
While the technology used in solar heating has been around for
ages, the systems themselves still can fall victim to the
occasional glitch. For detailed information on your specific
system, refer to the manufacturer’s manual. Following are six
typical solar system problems that service techs may encounter,
along with tips on how to fix them.
As with most controllers, whatever can go wrong with an actuator
valve can go wrong with these systems as well, experts say.
A common culprit is the pool owner, who often will leave the toggle
switch in the wrong position. When this happens, the pump
won’t operate even if the sensors indicate it should.
To remedy the situation, some simply glue the switch in place so it
can’t be moved. If the pool needs to be shut down for
maintenance, the tech can bypass the switch by going directly
through the control panel.
At the control panel, you’ll find the thermostat and a switch
that reads “automatic,” “on,”
“off” and so forth. All you need to do is turn it to
the off position when necessary; for instance, when you’re
The 10k-ohm sensors these systems use can wear out. If you suspect
this is the case, attach your meter to the sensor. It should
indicate that it’s getting at least 10k ohms. If it’s
not, it needs to be replaced.
3. Vacuum-relief valves
Vacuum-relief valves are plumbed into the system on the roof and
allow water to drain back into the pool. Because the valves open
and close, over time they can wear out.
Debris also can get inside and clog them. You can easily tell that
you have a problem when you notice water is coming off the roof,
Some models are engineered with the valve threaded in place. Others
use a clamp to hold it.
4. Panel connections
Rubber couplings or O-rings connect the panels. They have the
potential to leak if they loosen. Use a screwdriver to tighten up
the stainless steel clamps that surround them.
5. Isolation valve
Make sure the isolation valve is on. Turning it off while the solar
system is in automatic mode can cause severe damage to the pump in
the event the system turns on. If you need to service the pool
equipment, shut off the valve. But be careful to turn it back on
when you’re finished.
6. Panel problems
Modern polymer panels are made to last 25 years, but eventually the
tubing can split. Sometimes this may require a whole new panel.
Other times the individual channels that are broken can be plugged
off with a stainless steel screw, dowel or tapered rubber