The first warm stretch of summer arrives in Eastern Ontario, and homeowners do what they always do: they turn on the air conditioning. For most households, that’s the moment the electrical system works harder than it has all year. Central AC units draw a significant amount of power when they start up and when they run — and for homes with older panels or undersized service, that demand can push the system past what it was designed to handle.
If you live in a house built before the 1990s, there’s a real chance your panel was sized for a different era. Homes in Eastern Ontario that are 30, 40, or 50 years old were wired when a typical household used a fraction of the electricity we draw today. Adding central air conditioning, modern appliances, a hot tub, or an EV charger to a system designed for a simpler time is where the problems begin. None of it is cause for alarm — but it is worth understanding before the hottest months of summer arrive.
This post walks through what summer does to your electrical system, what warning signs to watch for, and what a panel upgrade actually involves, in plain terms.
Why Summer Is Hard on Your Home’s Electrical System
Summer is peak demand season for home electricity. Air conditioners, dehumidifiers, pool pumps, chest freezers in garages packed with produce from the farmers market — all of these draw power at the same time. Residential electricity consumption in Ontario climbs measurably from June through August, and that increase flows directly through the electrical panel in your home.
Your electrical panel is the distribution point for every circuit in the house. It takes the power supplied from the utility and routes it to your outlets, appliances, and hardwired equipment. Every circuit has a breaker sized to protect it from overload, but the panel itself has a total capacity — measured in amps — that limits how much power the home can draw at once. When you push that total capacity hard, day after day, the system lets you know.
What Central Air Actually Draws
A central air conditioning system typically draws between 15 and 50 amps when running, depending on its size and age. The outdoor compressor draws the largest share, and it creates a startup surge when it kicks on that briefly exceeds its steady running draw. Older systems tend to produce a more pronounced surge. If your home runs on 100-amp service and you’re also drawing power for a refrigerator, a stove, a water heater, and several other circuits, adding central AC to that mix puts you very close to the edge of what the panel is designed to handle.
Operating near the edge isn’t an immediate emergency, but it does mean you’re working with no margin for error. And no margin is exactly where problems develop over time.
Summer Appliances That Add Up
Air conditioning gets most of the attention, but it isn’t the only contributor. Window AC units — especially older ones — draw more power than most people expect, often 5 to 15 amps each. A chest freezer running in a hot garage works significantly harder than it does in winter. Pool and hot tub pumps run for extended hours. Even a clothes dryer running more often than usual in a household full of active kids adds to the cumulative draw.
Rural properties and farms in Eastern Ontario carry additional summer loads. Livestock ventilation fans, grain drying equipment, water pump systems, and irrigation controls can push agricultural electrical systems close to or beyond their rated capacity. If you’re running a seasonal operation and haven’t had your service reviewed in a few years, summer is when that oversight tends to show itself.
What Are the Warning Signs Your Panel Is Overloaded?
An overloaded or undersized panel doesn’t always announce itself dramatically. The signs are often subtle — things homeowners notice and assume are minor quirks of an older house. They’re usually not quirks. They’re the panel signalling that something is worth looking at.
Breakers Tripping More Often Than Usual
A breaker that trips occasionally is doing exactly what it’s supposed to do. A breaker that trips repeatedly — especially under the same conditions, like every time the air conditioning starts up — is telling you that circuit is regularly hitting its limit. If resetting the breaker has become a routine part of summer life, that’s worth a professional look.
Lights Flickering or Dimming When Appliances Start
When a large appliance powers on, lights in other parts of the house shouldn’t flicker noticeably or dim for more than a fraction of a second. A very brief flicker when a motor starts is common. Sustained dimming, or flickering that happens frequently throughout the day, suggests that startup surges from one device are affecting the whole panel. That’s a sign the system is operating near its limits.
You’re Still Running on 100-Amp Service — or a Fuse Panel
Many homes in Eastern Ontario, particularly those built before 1980, were wired with 60 or 100-amp service. That was entirely appropriate for the electrical demands of those decades. It’s not appropriate for how we live now. The Canadian Electrical Code and most utility guidelines recommend 200-amp service as the standard for new residential construction, and for good reason: modern homes simply draw more power than the homes those older panels were designed to serve.
If your home still has a fuse panel — one with glass screw-in fuses rather than breakers — the situation warrants more urgent attention. Fuse panels are considered obsolete technology, and some insurance providers in Ontario will not write a policy for homes that still have them.
What Does an Electrical Panel Upgrade Actually Involve?
A panel upgrade sounds more disruptive than it typically is. The work is licensed, permitted, and inspected by the Electrical Safety Authority (ESA), which means there’s a clear process with clear oversight every step of the way.
Upgrading from 100-Amp to 200-Amp Service
The most common residential upgrade is moving from 100-amp to 200-amp service. This typically involves replacing the main panel, upgrading the meter base and service entry conductors, coordinating with the local utility for a temporary power disconnect, and pulling the required electrical permit. Once the work is complete, it’s inspected by an ESA inspector before the utility reconnects power.
The work itself is usually completed in a single day. Homeowners are without power for a portion of that day while the work is being done and inspected. From booking to completion, most upgrades in Eastern Ontario take one to two weeks, depending on utility scheduling and permit timelines. It’s rarely as involved as homeowners anticipate.
What a Panel Upgrade Makes Possible
Beyond handling the electrical load you already have, a panel upgrade creates room for what comes next. Planning to add an EV charger? A hot tub? A home workshop? A backyard shed with power? All of those require available capacity in your panel, and a 200-amp panel with properly sized breakers gives you that room without having to manage your electrical load like a daily balancing act.
For rural Eastern Ontario homes that may eventually add a standby generator or solar panels, a properly sized, modern panel is the foundation everything else connects to. Getting the panel right first makes every future addition simpler and less expensive.
Frequently Asked Questions
Can a 100-amp electrical panel handle central air conditioning?
It depends on your home’s total electrical load. Many homes on 100-amp service have limited margin once central AC is added to the mix. A 100-amp panel is not inherently unsafe, but if you’re also running electric heat, a water heater, and several other major circuits, adding central AC may push the system past a comfortable operating range. A licensed electrician can review your actual load and give you a clear answer specific to your home.
What are the signs my electrical panel is overloaded?
The most common signs are breakers tripping repeatedly under the same conditions, lights flickering or dimming noticeably when appliances start, outlets or switch plates that feel warm to the touch, a faint burning smell near the panel, or a buzzing sound coming from the breaker box. If you notice any of these, have the panel inspected promptly. These signs don’t mean something has already failed — they mean the system is asking for attention before something does.
How much does an electrical panel upgrade cost in Ontario?
The cost varies based on your current service, the scope of the upgrade, and whether the meter base or service entry conductors also need replacement. A typical 100-amp to 200-amp residential upgrade in Eastern Ontario runs in the range of $2,000 to $4,000 installed, including the permit and ESA inspection. An accurate quote requires an on-site assessment of the existing panel and service entry. Any firm number given without seeing the job is an estimate at best.
Is it safe to add a window air conditioner to an older electrical panel?
Window AC units typically draw 5 to 15 amps depending on their size. Adding one unit to a circuit that isn’t already near capacity is generally fine. The concern is adding multiple window units, or adding one to a circuit already shared with other significant loads, on a panel that has little remaining capacity. If you’re unsure, a quick inspection before summer is a straightforward way to get a clear answer.
When is the best time to schedule a panel upgrade in Eastern Ontario?
Before summer is the ideal window — before the highest-demand months of the year. If you have an older home, a fuse panel, 60-amp service, or a 100-amp panel that you’re asking to carry a growing load, booking an assessment in May or early June means you’re not scrambling when temperatures peak in July and August.
Ready to Have Your Panel Looked At?
Your electrical panel isn’t something most homeowners think about until something goes wrong. That’s understandable — it sits behind a door, quietly doing its job, and most of the time it does it well. But summer is when the gap between what a panel was designed to handle and what you’re actually asking it to do becomes most visible.
If you’ve noticed any of the warning signs in this post — or if your home has older service and you’ve never had it reviewed — a conversation with a licensed electrician is a good place to start. Beattie Dukelow Electrical serves homeowners, farms, and businesses across Eastern Ontario, from Prescott and Brockville to the rural communities of Leeds & Grenville and Augusta Township. The team can assess your current panel, walk you through your options clearly, and help you make a confident decision without any pressure. Summer should feel comfortable at home. Your electrical system shouldn’t be part of the worry.