How to Lower Hot Tub Hydro Bills in Ontario Winters

Canadian winters are notoriously tough on outdoor spas. When temperatures plunge below freezing across Uxbridge, Port Perry, and the Durham Region, your hot tub's electric heater works overtime to keep the water at a soaking temperature.

Without smart energy management, running a spa from November through April can add $50 to $150+ to your monthly electricity bill. Fortunately, simple operational tweaks, proper insulation, and maintenance habits can dramatically trim heat loss and reduce winter hydro costs without sacrificing comfort.

1. Inspect and Upgrade Your Hot Tub Cover

Up to 70% of a hot tub's heat escapes directly through the top. If your cover is heavy, sagging, or waterlogged, the foam core has lost its insulating R-value and is leaking energy every hour.

• Check for Water Saturation: A healthy cover weighs 35–40 lbs. If your cover takes two people to lift and weighs 80+ lbs, the internal foam has absorbed moisture and needs replacement.
• Inspect the Center Hinge Seal: Heat escapes rapidly through the center fold if the heat-seal gasket is worn or torn.
• Keep Straps Locked: Lock down side straps to pull the cover tight against the acrylic lip, preventing wind from breaking the perimeter seal.

2. Add a Floating Thermal Blanket

A floating thermal blanket sits directly on the water's surface beneath your main cover.

• Reduces Evaporation: Evaporation is the single largest driver of surface heat loss.
• Double Layer Insulation: Creates an insulating dead-air space between the water surface and the main cover, cutting heating cycles by 10%–15%.
• Protects the Main Cover: Blocks harsh chemical vapours from degrading the underside of your expensive hardcover.

3. Maintain a Steady Temperature (Avoid Wild Fluctuations)

A common myth is that turning your hot tub down to 80°F (27°C) between daily uses saves money. In an Ontario winter, forcing your heater to raise 1500 litres of water by 20°F in freezing outdoor air uses significantly more electricity than maintaining a constant set-point.

• For Frequent Soakers (3+ times/week): Keep your spa at a steady 100°F–102°F (38°C–39°C).
• The "2-Degree Rule": If you want to drop the temperature, lower it by no more than 1°C to 2°C (2°F–4°F) when not in use. Lowering the water by just 2°F can cut heater energy use by up to 10%.
• For Away Periods: If you're travelling for a week, drop the set-point to 90°F–95°F (32°C–35°C), ensuring freeze protection remains active.

4. Close Air Venturi Controls When Not in Use

The air dials on top of your spa shell inject cool outside air into the water stream to create powerful jet massage action.

• Turn Air Controls Off: Always shut all air dials completely off when you exit the tub. Leaving them open pulls freezing ambient air through the plumbing lines, rapidly cooling the water and causing the heater to kick on immediately after you put the cover on.

5. Clean Filters Regularly & Keep Plumbing Clear

Clogged or dirty filter cartridges restrict water flow through the circulation system, forcing heater pumps to draw higher electrical amperage and run for longer periods.

• Rinse Filters Bi-Weekly: Spray down filter pleats with a garden hose to remove organic debris.
• Deep Clean Monthly: Soak cartridges in a specialized degreasing filter cleaner to strip body oils, lotions, and scale buildup. We use Dazzle Power Blue Cartridge Cleaner at the shop.
• Perform an Annual Line Purge: Biofilm and scale trapped inside internal plumbing restrict water circulation. A thorough line flush, drain, and refill before winter ensures optimal flow and heating efficiency. We use Dazzle Drain Prep at the shop.

Quick Winter Energy Savings Checklist

Action Item	Expected Impact	Difficulty
Close Air Valves After Every Use	Prevents rapid cooling	10 Seconds
Add a Floating Thermal Blanket	Saves 10%–15% on heat loss	Instant
Replace Waterlogged Cover	Cuts surface heat loss up to 25%	One-time Upgrade
Clean Filters Monthly	Optimizes pump efficiency & flow	30 Minutes
Lock Cover Straps Tight	Prevents wind lift & heat leakage	Daily habit

Need Help Efficiency-Proofing Your Hot Tub?

From replacing worn, heavy covers and supplying thermal blankets to executing a pre-winter Hot Tub Drain, Clean & Comprehensive Health Check, Main Street Pools helps Durham Region pool and spa owners keep winter hydro bills under control.

Book your Hot Tub Service with Main Street Pools today!