It’s that time of year. People start calling to get solar pool heating systems installed as pool temperatures drop. New system owners get to experience the luxury of a warm pool at no operational cost for the first time. Existing system owners are faced with a few common issues.
- “My pool level is going down. There must be a leak.”
- “My solar pool heating won’t turn on.
- “My pool is ‘only’ 80°. Just last week it was 85°.” (Also, “My pool is ‘only’ 80 degrees, but I have the controller set at 85°.”)
Each of these issues can be resolved without a service call in many cases. The answer is often very simple:
Pool Level Going Down
A leak in a solar pool heating system can cause the pool level to go down as pool water leaks from fittings or panels. Tree branches falling on equipment, animals chewing on things, and other physical trauma can occur during the summer when solar pool heating systems are turned off and isolated or bypassed. A leak should be evident, with water coming off the roof, at the equipment pad, or through gutter downspouts. However, there is a more obvious reason for pool levels to go down this time of year… evaporation! Pool owners often forget that dry, sunny, windy weather causes the rate of evaporation to skyrocket this time of year, meaning that you need to periodically add water to the pool. New homeowners often do not realize this fact. A suspected leak may simply be water evaporating faster than recent experience. A few inches per week can easily be lost to the atmosphere this time of year. (Word of caution: if you suspect an underground leak, contact a pool leak detection specialist to diagnose the problem.)

Solar Pool Heat Won’t Turn On
Solar Pool Heating systems often use automatic controllers and motorized valve actuators to turn the system on and off. If your solar pool heating system is not turning on, your valve actuator may have been placed in the manual off position (middle). You may need to experiment to see in which position the switch should be. Important: if you solar pool heating system has manual 2-way isolation valves, it is critical that you open these valves before turning on your solar pool heating system. Do not adjust your motorized actuator until you confirm that the solar pool heating isolation valves are open. Other reasons for solar pool heating systems not turning on include faulty sensors and incorrect controller settings. A call to your solar pool heating professional may help solve the problem. Otherwise, an annual system tune up is always a great idea to keep your system working properly and optimally.
My Pool is not Warm Enough
As temperatures dip, especially nighttime temperatures, the highest temperature of a solar heated pool will also drop. In Southwest Florida, optimally sized and oriented solar pool heating systems can achieve pool temperatures around 10 degrees higher than the Gulf of Mexico temperature. Higher temperatures are possible with the use of a pool cover, which traps the heat, especially at night. (Pool covers also reduce evaporation significantly.) Although solar heated pools will not reach summertime temperatures this time of year, the temperature is still very comfortable for most people. For example, the Gulf temperature today is 73° and a solar heated pool could be in the low 80’s. Because the high ambient air temperature today is expected to be 72°, an 80° pool will feel quite luxurious! Before you conclude that your solar pool heater is not working as effectively as it should, consult the local Gulf temperature page on the Solar Southwest Florida blog!
If you are still concerned that your solar pool heating system is not working properly or optimally after a long summer with the system off, give us a call and ask for an annual tune-up. It’s a cost effective way to make sure everything is in tip-top shape. Make sure you are home at the time of service and get re-familiarized with your system!