In South Florida, most pool heaters sit idle from May through October. Then the first cold front arrives, someone turns the heat on, and nothing happens. Or the heater runs, but the pool never gets past the low 80s.
Months without use are hard on heating equipment, especially on a coastal equipment pad. The good news is that most start-up problems have a short list of causes. Here is what we see most often each fall, and how to keep your pool comfortable through the winter.
Gas heaters: what goes wrong after a long idle period
Gas heaters such as the Jandy JXi, LXi and LRZ, Pentair MasterTemp, Hayward Universal H-Series and Raypak digital models are reliable, but they do not like sitting unused in heat and humidity.
Insects and debris in the burner area. Rodents, ants and wasps nest in quiet, sheltered spaces. In a heater, that can mean blocked burners or a dirty ignition area, which leads to failed ignition or a weak, uneven flame.
Damaged wiring. Small animals sometimes nest inside equipment cabinets over the summer and chew through wiring. The heater may show no power, an error, or work only some of the time.
Corrosion. Salt air reaches pads on Palm Beach island, along the Intracoastal in Fort Lauderdale or anywhere near the water. Corrosion on igniters, sensors, connections and the cabinet itself builds quietly over the summer and shows up the first time the heater is asked to work.
Gas supply. On propane homes, the tank may be lower than expected. On any gas heater, a valve closed during summer work or a storm is easy to overlook.
If a gas heater will not light, or lights and then shuts down, it is worth having it checked rather than resetting it repeatedly. Learn more on our gas pool heater page.
Low water flow: the most overlooked cause
Every pool heater needs a minimum amount of water flowing through it. A pressure or flow switch shuts the heater down if flow is too low, which protects the heat exchanger.
The most common reason for low flow today is not a broken pump. It is a variable-speed pump, such as a Jandy VS FloPro, Pentair IntelliFlo or Hayward TriStar VS, programmed to run at a low, efficient speed all summer. When the heater turns on, the pump may not be moving enough water for it to stay on.
A dirty filter or partly closed valve can cause the same problem. Most automation systems can be set to run the pump at a higher speed whenever the heater is on, which solves this without giving up efficiency the rest of the time.
Heat pumps: why the pool will not get warm
Heat pumps, including Jandy VersaTemp, JE heat pumps, Pentair UltraTemp, Hayward HeatPro and Raypak Crosswind, move heat from the outside air into the water. They are efficient in South Florida’s mild climate, but they behave differently from gas heaters.
- Output drops as the air gets colder. On the coldest nights, a heat pump may struggle to hold temperature or stop until it warms up.
- They heat slowly. A heat pump is best at holding a temperature, not raising it quickly. Turning it on the morning guests arrive usually is not enough.
- They need airflow. Landscaping that grew in over the summer, or debris on the coil, reduces performance.
- Coastal corrosion. Salt air attacks coil fins and electrical parts, which reduces output over time.
Check the automation before calling for service
On homes with automation, the heater itself is often fine. Before booking a repair, check the system in iAquaLink, IntelliCenter, ScreenLogic, the Pentair Home app or OmniLogic:
- Is the heater enabled for the pool or the spa, and is the set point above the current water temperature?
- Is the pump scheduled to run long enough for the heater to work?
- Did a power outage or storm reset settings or schedules?
If you are not sure how your system is set up, our automation team can review the programming and pump speeds in one visit.
Using your pool all winter
Many owners in Palm Beach Gardens and along the coast use the pool year-round. A few practices make that easier:
- Pair the heater to how you use the pool. Gas heats quickly and suits the spa and occasional weekend use. A heat pump costs less to run when you want the pool held at a steady temperature for weeks. Many larger homes use both.
- Warm it up before you arrive. With iAquaLink, the Pentair Home app or OmniLogic, you or your estate manager can turn the heat on from a phone a day or two before you get home.
- Have the heater checked in the fall. A visit before the first cold front catches burner, flow and corrosion problems before you need the heat.
We repair and replace heaters and heat pumps from Jandy, Pentair, Hayward and Raypak, and provide warranty service on Jandy, Pentair and Raypak. See our Jandy, Pentair, Hayward and Raypak pages, or our service areas in Palm Beach and Fort Lauderdale.
FAQ
Why does my pool heater turn on and then shut off after a few minutes? The most common causes are low water flow, often from a pump running at a low speed or a dirty filter, and ignition or flame-sensing problems on gas heaters. Both should be checked by a technician rather than reset repeatedly.
Is a gas heater or a heat pump better for winter swimming in South Florida? A heat pump costs less to run when you keep the pool warm for long stretches. A gas heater heats much faster and handles cold snaps and spa use better. Many larger homes use a heat pump for the pool and gas for the spa or quick heat-ups.
Should I have my heater serviced before winter even if it worked last year? Yes. After months of sitting idle in heat, humidity and salt air, problems like insect nests, damaged wiring and corrosion are common. A fall check finds them before the first cold front.
Ready to heat your pool this winter? Call Swimming Pool Controls at (954) 383-8178 for upfront pricing on heater service and repair.
