What size portable generator do I need to keep my fridge and sump pump running during a power outage?

For most GTA homes, a 3,500–5,000 watt portable generator will keep your fridge and sump pump running during a power outage, with enough headroom to add a few lights and phone chargers.

This is one of the most practical questions a Toronto homeowner can ask — after the 2013 ice storm left hundreds of thousands of homes dark for up to 10 days, portable generator sales across the GTA surged dramatically. A flooded basement from a failed sump pump during a winter storm can cause $20,000–$50,000 in damage, so getting this right matters.

Understanding the Wattage Math

The key to sizing a generator is understanding the difference between running watts and starting watts. Motors — like the ones in your fridge compressor and sump pump — draw 2–3 times their running wattage for a fraction of a second when they start. Your generator needs to handle that surge without stalling.

A typical refrigerator runs at 150–400 watts but surges to 800–1,200 watts on startup. A standard ¾ horsepower sump pump runs at 750–1,000 watts but surges to 1,500–2,000 watts on startup. Add those peak demands together and you're looking at a potential simultaneous surge of 3,000–3,200 watts — and that's before a single light bulb. A 3,500W generator handles this comfortably under normal conditions, but a 5,000W unit gives you meaningful headroom for a few LED lights, phone chargers, and a lamp or two without pushing the generator to its limit.

If your home has a chest freezer in addition to the fridge — very common in GTA bungalows with finished basements — add another 400–600 running watts and 1,000–1,500 surge watts to your calculation. At that point, a 5,000–6,500 watt generator is the smarter choice.

GTA-Specific Considerations

Toronto's ice storms are the defining scenario here. During a January ice storm, you're not just running a fridge and sump pump — you're also dealing with a home that's rapidly losing heat. If you have electric baseboard heating, a portable generator won't realistically power it (a single 1,500W baseboard heater is already a significant load, and most homes have several). If you have a gas furnace, the furnace itself only needs 300–600 watts to run the blower and controls — that's very manageable and worth adding to your list.

Fuel storage is a serious consideration in Ontario winters. Gasoline degrades in 30–60 days without a fuel stabilizer like Sta-Bil. Many GTA homeowners keep 10–20 litres of stabilized fuel stored safely in approved containers in a detached garage. During a major ice storm, gas stations lose power too — the 2013 storm created lineups of hours at the few stations that remained operational. Store fuel before you need it.

Safety is Non-Negotiable

Never run a portable generator indoors, in a garage, or near any window or door. Carbon monoxide poisoning kills people every year during Ontario power outages — it is odourless and lethal within minutes at high concentrations. The generator must run outside, at least 3 metres from any opening. In a January ice storm, this means you'll be going outside in the cold to manage it — factor that into your planning.

Connecting a portable generator to your home requires a proper transfer switch or interlock kit installed by a licensed electrician. Plugging appliances directly into the generator with extension cords is the safest temporary approach, but running the generator through your home's wiring without a transfer switch creates backfeed — energizing the utility lines and potentially killing a Toronto Hydro lineworker restoring power in your neighbourhood. This is both illegal and genuinely dangerous.

A manual transfer panel installed by a licensed electrician costs $1,500–$2,500 and lets you safely connect your generator to selected circuits through your panel. This is the right long-term solution for any GTA homeowner who plans to use a generator regularly.

For a portable generator in the 3,500–6,500W range, expect to pay $800–$2,000 for the unit itself at Canadian Tire, Home Depot, or an equipment dealer. Honda and Generac are the dominant brands in the GTA market, with Honda's EU series being particularly popular for its fuel efficiency and quieter operation.

If you're ready to take the next step and have a transfer switch installed, Toronto Electrical Repair can match you with a licensed electrician in your area — it's a free service. You can also browse electrical professionals through the Toronto Construction Network directory at torontoconstructionnetwork.com/directory?trade=electrical.