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Trouble Shooting
Many times we go to a service call on one of our systems and
find some basic problem that is not a warranty issue at all, but
a problem with the way the system is being run, or other pool
problems that are affecting the solar system. Although we pride
ourselves on making prompt service calls, the following checklist
of common problems, some of which you can remedy, can save all
of us some aggravation.
- Flow Issues: Each solar collector needs a
minimum flow rate to work efficiently. Most systems need 30-60
gallons per minute (GPM) depending on size. (For example:
One HC 50 collector needs 5 GPM. So if you have 8 HC 50 collectors
your minimum system rate is 40 GPM). It is always better
to be little over that minimum especially if the collectors
are split into two or more banks, to assure full flow to each
individual collector. In rare situations there can be too much
flow; at double the recommended rate and higher, the efficiency
can be impaired. The most common causes of low flow are:
- A dirty filter
- A clogged pump basket
- A problem with the pump itself; motor, impeller, seals,
etc.
- Undersized pump and or plumbing
- Obstructions or suction leaks on plumbing lines
Ironically, low flow often produces a result that masks the
problem. The water that comes back to the pool is real hot,
so it seems that the solar is really working well. In fact,
pool heating relies on a large volume of water being heated
a little bit, rather than a little bit of water being heated
a lot. If you have a system that was working well and now
is not, check your filter, pump basket, etc., make sure the
flow rate is what it was in the beginning. One way to check
flow rate is to physically feel all the collectors while the
system is running. They should be running uniformly cool.
Warm or hot panels usually signify inadequate flow. A flow
meter installed properly on the return line can give the most
accurate reading of all, but usually is not necessary. Most
new pools have flow rates for basic filtration that exceed
minimum flow rates for solar.
- System Settings: There are two common mistakes:
- Not enough hours or the wrong hours.
The solar must run long enough to do the job. Usually 5-6
hours, sometimes more. We are trying to turn a large amount
of your pool volume, preferably all of it, through the system
each day. You can save electricity by running your pool
pump for only 2 hours a day, but it probably won’t
achieve filtration or heating. And the time you run the
system must be when the sun is the hottest on the panels.
This is usually afternoon hours, a little earlier for east
facing systems. Remember- in most cases the auto control
will not turn the pump on and off, it only moves the diverter
valve. You must set your time clock, or computer control
for afternoon run times.
- Wrong settings of solar control devices.
The auto control must be set on auto. Quite often owners
don’t understand why it isn’t coming on at the
first hint of sunlight and turn it on in the manual mode.
The auto control is smarter than you are. It will only send
water to the collectors if there is potential for heat.
(A common scenario: The pool is quite warm from the
previous day’s heating but today is a cooler, or breezier
day. Yes the sun is out, but if you force the system on
in manual setting, you are cooling your pool. And if you
leave the system on manual and it runs during really cold
weather, or at night, you are achieving the opposite of
what you want.) The other common mistake is to reverse
the actuator toggle. If that happens the system will be
doing the opposite of what it thinks it is doing. On hot
days it will send no water to the collectors, and on cold
days it will. Great if you live in Las Vegas and your pool
is too hot, but not that good in Northern California. Make
a note of the correct toggle position at start-up and forget
you ever saw it. Leave it alone.
- Air Bubbles Back To Pool. Most systems will
have large amounts of air returning to the pool whenever the
system turns on. This is normal. Even if the pump has been running
continuously, if the solar valve has moved to the off position
some water may have drained from the panels back to the pool,
and when it turns back on more air comes back to the pool. If
the bubbling is constant there may be a problem. Usually it
is a result of low flow. The pump is not forcing water to the
roof fast enough and gravity is pulling it down faster. This
produces a little vacuum at the top of the system and air is
sucked in at the vacuum relief valve or elsewhere. It is possible
to replace or relocate the vacuum relief valve, or to restrict
the return line back to the pool. In most cases however that
just hides the real problem, which is flow, and the system is
probably not operating at peak efficiency. The other source
of air bubbles is a suction leak at the pump or supply plumbing.
Usually this will cause air to come back to the pool with or
without the solar running, so the solar can be eliminated as
the source.
- Noise. The system will make some noise when
it turns on as the air is returned to the pool. If the solar
lines are against the wall of the house you may hear it. After
the system is purged of air the pipes should not make any noise.
When the system turns off some water will drain back to the
pool. This also can be a little noisy and may last a little
longer. Sometimes the solar valve may not turn to the off position
until later in the evening and will cause the draining to make
noise then, even though the pump has been off for some time.
Also the vacuum relief valve may make some noise as it allows
the air in as the system drains. Loud banging or thumping noises
are not normal and need to be investigated. If system noise
is bothering you, especially at night, give us a call and we
may be able to help.
- Sensor Problems. The auto control will indicate
that a sensor is out. If this indicator is lit, call for service.
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