The first warm weekend of the season is when pool heaters get tested, and when we get the most no start calls. After months sitting idle, a gas pool heater can collect debris, insects and moisture that stop it firing or make it unsafe to run.
This checklist covers what to look at before you turn it on, and the signs that mean you should call a technician instead.
Before you touch the controls
Walk around the heater and look carefully. Insects and small animals love the shelter over the winter.
- Remove leaves, nests and debris from around and on top of the unit.
- Check for rust, cracked panels or signs of rodents.
- Make sure the venting area is clear.
- Confirm the gas valve and power supply are in place and undamaged.
Get the water moving first
A pool heater will not fire unless the pressure switch senses enough water flow. Open the pool fully, run the pump, and clean the skimmer and pump baskets. Backwash or clean the filter if needed. Low flow is the single most common reason a heater refuses to start in spring.
Starting the heater
Follow the manufacturer's startup procedure on the unit. Watch for ignition and a steady flame through the viewing port if your model has one. Listen for unusual noises, and give it time to raise the water temperature.
If you smell gas, see soot, hear repeated ignition attempts without a flame, or notice a yellow flame, turn the heater off and call a technician.
Call (289) 801-7262Not sure it's a DIY fix?
Describe the symptom over the phone and a HeatNest technician will tell you what it likely is and what a repair involves.
Call (289) 801-7262Common error codes and what they mean
Codes vary by brand, but most fall into a few groups: pressure switch or flow errors, ignition failures, high limit trips and sensor faults. A flow error usually means a dirty filter or a closed valve. Repeated ignition failures often trace back to a blocked burner or a weak igniter.
Professional startup service
A spring startup visit includes cleaning the burner tray, inspecting the heat exchanger, testing the igniter and safety controls, and checking gas pressure. It is the easiest way to make sure the first swim of the year is a warm one.
Common questions
+Why won't my pool heater turn on in spring?
Low water flow, a tripped pressure switch, debris in the burner, or a failed igniter are the most common causes.
+How long does a pool heater take to warm the pool?
It depends on pool size, heater size and weather. Expect hours to days, not minutes, for the first heat up.
+Should I cover my pool to save heat?
Yes. A cover reduces heat loss significantly and helps the heater keep up.
+Can I clean the burners myself?
Burner work involves gas components and is best done by a licensed technician.
+When should I book a spring startup?
A few weeks before you plan to open the pool, before the seasonal rush.