No Hot Water
Check that the solar water heating systems circuit breakers are in the “ON” position. Turn the switch on the timer to “ON” and wait 15 minutes. If the water doesn’t heat up, turn the timer switch and water heater circuit breakers off and remove the top access cover on the tank with a Phillips screwdriver.
Next, remove the insulation, says your local Santa Cruz plumbing experts, and check that the thermostat is set between 110° and 120°. Press the red button. You should hear a click and the water will start heating when you turn the power back on. You may be able to hear it boil. If the button was not popped out, call your local Santa Cruz plumbing technician.
No hot water in the morning
Carefully touch the solar pipes or fittings above the solar tank (they are the smaller pipes) in the evening. Both the pipes and the fittings should be cool or one just slightly warmer. If one is very hot and the other cool, it means that the hot water is rising up to the panels at night, cooling off in the cool night air, and cooling off the tank. This could be caused by a malfunctioning check valve. If both pipes are hot, check to see if the pump is running.
Pump running at night
Check that the solar controller switch is set to “automatic.” If it is, according to your local Santa Cruz plumbing specialists, and the pump runs continuously at night, there is most likely a problem with the solar sensors, wire, or controller. If the pump only comes on occasionally at night, refer to the above paragraph regarding check valve malfunction.
Knocking noises heard in the tank
If the solar high limit control is set too low, says the experts at Duncan plumbing, the pump could shut off when the sun is still shining. This causes water in the panels to boil and send steam down into the tank. Set the high limit on your controller all the way up and have an “automatic cooling thermostat” installed that will leave the pump running into the evening to cool the tank down.
PLUMBING TRADE SECRETS: You could also have a tempering valve installed if you need to limit the temperature of the water. Another solution is to have a 40 or 50 gallon tank added to your system to absorb that extra hot water and save it for a rainy day.
Not every plumbing need, needs a plumber!