A 100 amp service is a starting fact, not a verdict.
A ducted heat pump added to a gas furnace can have a very different electrical load from an all-electric heat pump with large resistance backup. EV charging, electric water heating, ranges, dryers, hot tubs and future electrification can also change the service calculation.
The correct next step is a load assessment by the HVAC designer and, where electrical work is involved, a Licensed Electrical Contractor. The quote should identify the heat pump’s electrical requirements and any backup heat rather than simply promising that “100 amps is enough.”
What the electrical review should look at.
The electrical review should compare the existing service and panel with the actual proposed equipment. That includes the outdoor unit nameplate, minimum circuit ampacity, maximum overcurrent protection, indoor equipment, resistance backup if any, and other major household loads.
If the project changes wiring or service equipment, Ontario electrical work must follow the Ontario Electrical Safety Code. ESA states that hired electrical work must be done by a Licensed Electrical Contractor, and most electrical work requires a notification of work.
Three common project paths.
A professional assessment may lead to more than one valid path. The table below shows the questions to verify rather than assuming every 100 amp home needs the same solution.
| Path | When it may fit | What still needs verification |
|---|---|---|
| Hybrid heat pump + gas furnace | The heat pump handles much of the season while the furnace provides backup. | Exact compressor circuit, controls, furnace compatibility and whole-home load. |
| All-electric with managed loads | The home may avoid or defer a service upgrade by managing coincident electrical loads. | Code-compliant load calculation, approved equipment and control strategy from a Licensed Electrical Contractor. |
| Service or panel upgrade | Used when the existing service cannot support the planned loads or when broader electrification is part of the project. | Utility requirements, ESA work, meter/service equipment, site conditions and final cost. |
Ottawa financing can include required electrical work.
Better Homes Ottawa lists associated electrical equipment, electrical wiring and panel upgrades among eligible measures when they are part of an approved retrofit. That does not mean every panel upgrade is required or automatically approved; it means the loan can help finance qualifying work within the program rules.
The current Better Homes Ottawa loan is not 0%. It is published at 4.33% fixed for 20 years, with a 4% administrative charge. Complete the program steps before starting work if you want to use the financing.
Questions to ask before approving electrical work.
A good quote separates “required for this heat pump” from “recommended for future electrification.” Both can be sensible, but they are different decisions.