For most Canadian docks and boat lifts, a 3/4 HP Kasco de-icer (3400D or 3400HD) is the right size; step up to 1 HP (4400D/4400HD) for exposed sites, harsh prairie winters, or larger areas, and down to 1/2 HP (2400D) for a single dock in a milder region. The right answer comes from Kasco's own sizing chart, which works from two questions: how cold does your region get, and how will the unit be mounted?
The Kasco de-icer lineup
Kasco makes five de-icer models, all with a 3-year warranty and sacrificial zinc anode: the 2400D (1/2 HP, 120V, 5.4 amps), 3400D (3/4 HP, 120V, 6.6 amps), 3400HD (3/4 HP, 240V, 3.1 amps), 4400D (1 HP, 120V, 9.1 amps), and 4400HD (1 HP, 240V, 4.5 amps). The D and HD versions of each size are the same de-icing performance — the difference is voltage, and the 240V models draw roughly half the amps, which matters if your dock circuit is already loaded.
How much open water each size creates
From Kasco's published sizing chart, mounted at an angle in a moderate Canadian winter (average lows of −7°C to −18°C — typical for southern Ontario):
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1/2 HP: roughly 25 x 60 ft of open water
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3/4 HP: roughly 30 x 80 ft
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1 HP: roughly 35 x 90 ft
In severe cold (average lows of −18°C to −29°C — prairie and northern conditions), those areas shrink: about 25 x 55 ft, 30 x 75 ft, and 35 x 85 ft respectively, and vertical mounting opens smaller circles of roughly 35, 50, and 65 ft diameter. The pattern to notice: the colder your region, the more it pays to size up one step.
Angled or vertical?
Vertical suspension opens a circle directly below — the simple choice for keeping a gas-exchange hole open for fish. Angled mounting (with a universal dock mount or float) directs the thrust along a dock face or boat-lift area, opening a longer oval exactly where structures need protection. Most dock and marina installations should be angled; most fish-pond installations can be vertical.
Depth and placement
De-icers need at least two feet of water and should hang well off the bottom to avoid stirring debris — four to six feet deep is typical for vertical installs. Shallow sites, unusual structures, and multi-slip marinas often need more than one unit or a specific placement plan; that's a photo-and-dimensions email to us rather than guesswork.
Complete the setup
Every de-icer should run on a C-10 thermostat panel (or the C-20 with timer) so it operates only when temperatures require — the amp figures above are exactly why: a 4400D drawing 9.1 amps around the clock is a very different hydro bill than one on a thermostat. Mounting kits and replacement parts, including zinc anodes, are stocked. And if you're deciding between a de-icer and a bubbler-style system, our comparison guide covers that first.
Frequently Asked Questions
What size de-icer for a single residential dock in Ontario?
A 3/4 HP unit (3400D on 120V, or 3400HD on 240V) angled along the dock face is the standard choice — roughly 30 x 80 ft of open water in a typical southern Ontario winter.
Should I buy the 120V or 240V version?
Performance is identical. Choose 240V (3400HD/4400HD) if your shore power offers it — the unit draws about half the amps, which is easier on shared dock circuits.
Can one de-icer protect a boat lift and a dock?
Often yes, if they're adjacent and the unit is angled to sweep both — in severe-cold regions or with spread-out structures, plan on one unit per structure.
Do I need a bigger unit in Manitoba than in Toronto?
Effectively yes — the same unit opens noticeably less water in prairie cold, so sizing up one step is the safe play in harsh regions.
Send your dock dimensions, water depth, and town to Info@fountaindepot.com or call 905-752-1226 for a no-charge sizing recommendation from an authorized Kasco repair shop.
August 18, 2026
August 10, 2026
