Last week we discussed how often you should change your hot tub water in Ontario’s winters. One of the follow-up questions we received was what to do if the hot tub freezes.
A frozen hot tub is a winter headache nobody wants, but it happens more often than you think. The good news: if you act early, you can usually prevent major damage to your pump and plumbing.
So here’s what to do first, what not to do, and when to call a professional.
First, Safety Matters
If your hot tub has already frozen or stopped heating:
- Turn off the power at the breaker
- Do not run the jets or circulation pump
- Do not try to chip or smash ice inside the tub
- Avoid using open flames or high heat tools (torches, heat guns, etc)
Important: Frozen hot tubs can quickly lead to burst pipes and leaks. Thawing and equipment work should be handled by a professional spa technician or plumber.
How Hot Tubs Freeze in Winter
Most freeze-ups happen because of:
- Low water levels (evaporation or leaks)
- Power outages
- Weak or failing pumps
- Blocked filters
- Cold snaps below –15°C
- Insufficient insulation or worn-out covers
What You Can Do Right Now (Safe Steps)
If your hot tub is partially frozen or losing heat:
Protect the equipment area from the wind
Place a tarp or blanket over the equipment bay (leave room for airflow).
Keep the heat you have
Make sure the cover is fully sealed and locked to prevent heat loss.
Check your water level
If water is below the jets, top it up right away, running low increases freeze risk.
Use warm (not hot) water to top up
When to Call a Professional Immediately
- Water has already frozen around plumbing
- You hear grinding from the pump
- Water level keeps dropping
- No power to the spa after a freeze
- You notice leaks after thawing
Hot tub repairs are not really DIY-friendly once freeze damage starts. A professional should inspect lines and pumps before restarting.

Preventing a Frozen Hot Tub (Ontario Winter Checklist)
- Keep water above the jets
- Replace worn cover seals
- Set freeze protection mode if available
- Keep a backup water plan if you’re on cistern or well water
- Schedule regular top-ups, low water is the #1 cause of freeze issues
- Use a thermal blanket inside for extra insulation
Need Water for Your Hot Tub in Winter?
If low water levels caused your freeze-up or you need a safe refill before restarting, Mountain Services provides winter bulk water delivery across:
Blue Mountains, Thornbury, Collingwood, Meaford, Owen Sound, Grey-Bruce, and surrounding areas.
- Fast delivery
- Clean, treated water
- Safe for cisterns and hot tubs
- Avoid draining your well in winter
Call 226-256-7905 or book online.
Safety Note
This article provides general safety guidance only. Mountain Services does not provide hot tub repairs or equipment service. Always consult a qualified spa technician before operating or repairing heated water systems.