Markham · Alectra Utilities service area
Markham electrical panel and service upgrades
In Markham, a panel upgrade can mean replacing a tired 100 amp service in a 1980s home or finding room in a newer panel that filled up fast. We size it from a load calculation and book the utility work with Alectra.
Why the job varies
Panels across Markham's neighbourhoods
The oldest panels in Markham sit in the heritage houses of Unionville and Markham Village. Some have been updated more than once. Others still carry an old service, and occasionally fuses, under a century of renovations.
The subdivisions of the 1970s, 80s and 90s are where we do the most upgrades. Many of those homes in Milliken, Buttonville and older parts of Unionville were built with 100 amp services. They were fine for one family with gas heat. They struggle once a charger, central air and a finished basement are added.
Newer towns such as Cornell, Cathedraltown, Wismer and Greensborough usually have 200 amp breaker panels. The usual problem there is space, not size: the builder filled the panel, and there's nowhere to land a new circuit. In Angus Glen, large homes with several systems sometimes need more than 200 amps.
By neighbourhood
What a Markham upgrade tends to look like
A rough guide only. Each home gets its own load calculation.
| Heritage cores | 1970s to 90s subdivisions | Late 1990s to today | Angus Glen | |
|---|---|---|---|---|
| Typical panel | Mixed, sometimes fuses | 100 amp breaker panel | 200 amp breaker panel, often full | 200 amps or more |
| Usual trigger | Insurance or a renovation | A charger or central air | New circuits with nowhere to go | A generator, pool or extra chargers |
| Likely answer | A new service and panel | An upgrade to 200 amps | A sub-panel or rearrangement | A larger service, sized from the loads |
Signs
When a Markham home is due for one
The main trips on hot evenings
Air conditioning, cooking and laundry together can push a small service past its limit.
No spaces for a new breaker
Common in newer homes where the builder used every slot.
An EV on the way
A Level 2 charger needs a dedicated 240-volt circuit and spare capacity.
Fuses or a very old panel
Insurers often ask about these when you buy or renew.
With Alectra Utilities
How upgrade day runs in Markham
Ahead of time
We file the ESA notification and book the disconnect and reconnect with Alectra.
Power off
Alectra disconnects the service, usually in the morning.
The swap
We install the new meter base and panel, then move and label every circuit.
ESA
The work is inspected and the connection is authorized.
Power back on
Alectra reconnects and we test the main circuits with you before we leave.
Planning ahead
Room for what comes next
An upgrade is the right time to think about the next ten years. If a heat pump, a second car or a generator is likely, we leave spaces and capacity for them now. A transfer switch for backup power also sits beside the panel, so it pays to plan both at once.
In heritage homes, we often find older wiring during the move to the new panel. We'll tell you what we see and whether it needs attention. Read more about our panel upgrades, or see everything we do in Markham.
Questions
Panel upgrades in Markham: questions
Our 1980s house in Milliken still has 100 amps. Is that enough?
For the house as it was built, often yes. The trouble starts when you add a charger, central air, a basement kitchen or a hot tub. A load calculation tells us whether 100 amps can carry your plans. If it can't, we quote the upgrade with the same visit.
Our Cornell home is only a few years old, but the panel is full. Do we need a new service?
Not always. A full panel has no spare spaces, but the service may still have capacity. Depending on the panel, a sub-panel or a rearrangement can make room. The load calculation shows whether more amps are actually needed.
Does the heritage district affect a panel upgrade in Unionville?
The panel itself is inside, so usually not. It can matter if the meter or the service mast has to move on the outside wall. We try to keep them where they are, and we flag any visible change early so you can check with the City of Markham.
How long is the power off during a panel upgrade?
Usually most of one working day. The utility disconnects the service in the morning, we swap the panel and service equipment, and power is reconnected once the work is ready. We book the utility appointment for you and tell you the date in advance.
More in Markham