How Much Electricity Does a Block Heater Use?
What plugging in actually costs per night and per winter in every province — with the math shown, and the one habit that cuts the bill by two-thirds.
The math
Energy = wattage × hours. A 400 W block heater running 4 hours uses 1.6 kWh. At a typical Canadian residential rate of 10–18 ¢/kWh, that's 16 to 29 cents per plug-in. Run it every night for a five-month winter (150 nights) and you're at $24–$43 for the season.
Leave the same heater plugged in 12 hours a night instead, and the season costs $72–$130. Same starting benefit, triple the bill — this is the entire case for a $20 timer.
By province (approximate residential rates)
Quebec (~7¢/kWh): about 11¢ per 4-hour plug-in — the cheapest block-heating in North America. Manitoba (~10¢): about 16¢. BC (~11–14¢): 18–22¢. Saskatchewan (~15¢): about 24¢. Alberta (variable market, ~10–18¢): 16–29¢. Ontario (time-of-use, ~7–15¢): 11–24¢ — and here's a genuinely useful trick: Ontario's overnight ultra-low rates mean a timer that runs 4:00–7:00 a.m. hits the cheapest power of the day.
Even at the most expensive rates in the country, a full winter of disciplined timer use costs less than a single tank of gas — set against reduced engine wear, instant defrost, and never paying for a cold-start boost.
Compare: the cost of NOT plugging in
A boost call runs $50–$150 if you're not on a plan. A new battery killed early by deep-cold cranking: $150–$300. The engine wear from a -30°C dry start is harder to price, but a measurable share of lifetime cylinder wear happens in cold-start seconds. The block heater is the cheapest component in your entire winter kit — the electricity is a rounding error.
FAQ
How much does it cost to run a block heater overnight?
A 400 W heater for 12 hours uses 4.8 kWh — roughly 35–85 cents depending on province. On a 4-hour timer it drops to 11–29 cents.
Does a block heater use a lot of electricity?
No. On a timer it uses 1.5–2 kWh per night — about the same as running a modern dishwasher cycle, and $25–$45 per winter in most provinces.
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BN-LINK 24-hour mechanical outdoor timer
The classic dial timer in an outdoor-rated case, 15 A resistive. Nothing to program, nothing to reset — set the pins for 3–4 hours before departure and forget it.
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