Troubleshooting a Swim Spa That Won’t Heat
Is your swim spa suddenly cold? If the heater’s running but your water stays chilly, don’t worry — heating issues are common and usually easy to troubleshoot.
This article will cover:
- The most common reasons a swim spa won’t heat
- DIY checks you can do at home
- When to call a professional
Let’s walk through the most likely culprits and how to fix them.
Step-by-Step Guide to Winterizing Your Swim Spa in Canada
1. The Water Level Is Too Low
Low water levels can cause heaters to shut down to avoid damage. Top up the water so it's covering all jets and check again.
2. Dirty Filters Are Restricting Flow
If filters are clogged, they can slow water circulation — causing the heater to turn off. Remove and clean your filters regularly. If they’re over a year old, replace them.
3. Faulty or Tripped Heater
Check your control panel for any heater-related error codes. Common ones include:
- FLO: Flow issue (usually dirty filters)
- OH: Overheat (possibly a sensor issue)
- DR or DRY: Dry heater (low water flow)
Reset your spa after cleaning filters and topping up water. If codes persist, a technician may need to check the heater element or temperature sensor.
4. Airlock in the Plumbing
After draining and refilling, air can get trapped and block flow. Try “burping” your spa:
- Turn jets on/off
- Open union fittings to release trapped air
5. Circuit Breaker Tripped
A sudden loss of heat could mean a GFCI trip. Reset the breaker and monitor your spa. If it trips again, call an electrician.
6. Spa Cover Not Retaining Heat
A worn-out or ill-fitting spa cover allows heat to escape rapidly. Inspect your cover and consider replacing it if it feels waterlogged or saggy.
When to Call a Pro
If:
- You’ve tried the above and your spa still won’t heat
- You see error codes related to electronics
- You hear odd noises from the heater or pump
…then it’s time to contact a certified technician.
Troubleshooting a Swim Spa That Won’t Heat
Swim spas that won’t heat are frustrating, but in most cases, it’s a fixable issue involving water level, filtration, or circulation. Follow the checklist above, and your water should be toasty again in no time.
Still have questions? Reach out to your local Hydropool retailer here: Find a Hydropool Retailer
