If your hot tub is running but the water won’t heat, don’t panic. Most heating problems are caused by flow, settings, sensors, filters, or power resets — not a dead heater.
1. Quick safety scan
- Smell burning or see smoke?
- Water leaking near wiring or pumps?
- Pump making grinding or loud clicking noise?
2. Check temperature, mode & basic settings
- Is the set temperature higher than current water?
- Is the tub in Economy or Sleep mode?
- Did power recently go out? (settings often reset)
3. Filters & water flow (common fix)
Heaters require good flow. If flow is restricted, the heater may shut off for safety.
- Turn power OFF at the breaker.
- Remove filter(s) and rinse thoroughly.
- Check water level — must be above skimmer line.
- Restore power and check circulation.
Helpful items for hot tub heating issues
- Replacement filter cartridges
- Filter cleaning spray
- Air-lock purge tools
- Water test strips
Once this page gets real traffic, affiliate links will be added — only trusted tools.
4. Power & breaker reset
- Locate dedicated hot tub breaker.
- Turn OFF → wait 30 seconds → turn ON.
- Watch panel for startup codes or errors.
5. When to call a technician
- No heat after filter & reset steps
- Breaker trips when heater activates
- Repeating error codes
- Scorch marks / melted plastic in equipment area
6. Preventing future heating problems
- Rotate or clean filters monthly
- Check cover for insulation damage
- Keep consistent water level
- Schedule pre-winter inspection if used year-round
Soon, FixifyHome will include a guided flow test & summary tool — so you know if it’s safe to continue or time to call a technician.
7. Hot tub won’t heat – FAQ
Why won’t my hot tub heat?
Usually water flow, safety sensors, heating modes, or filter issues.
Is slow heating a problem?
If breaker stays on and no errors — it’s usually insulation or flow. If codes appear, stop using it.
Can cold weather stop heating?
Yes. Poor insulation + bad cover can make a heater struggle for hours.