Electrical for HVAC and Heat Pump Circuits

HVAC electrical starts with the equipment nameplate, not a guess

Heat pumps and air conditioners need a properly sized branch circuit, a safe disconnect at the outdoor unit, and wiring that matches the manufacturer’s installation instructions. We handle that electrical scope so the HVAC contractor is not waiting on installation day for power that should have been ready.

The key numbers are usually on the condenser or air handler nameplate: minimum circuit ampacity, maximum overcurrent protection, voltage, phase, and whether the unit needs a fused or non-fused disconnect. Those numbers tell us the conductor size, breaker size, and disconnect type. We do not size a heat pump circuit by tonnage alone.

Typical scope can include:

• A dedicated 120V or 240V circuit from the panel
• New breaker space assessment and panel labelling
• Outdoor-rated disconnect mounted near the condenser
• Liquid-tight flexible conduit from disconnect to unit
• Weatherproof fittings and strain reliefs
• Bonding and grounding of the equipment circuit
• Power for an indoor air handler, condensate pump, or controls where required
• ESA notification where required and inspection coordination

This page is for the electrical work behind the HVAC installation. If you simply need a new circuit for another appliance or piece of equipment, see our dedicated circuit installation service.

You need this before the HVAC crew arrives, not after

The best time to call us is when you have the heat pump or AC quote and the model numbers are known. At that point, we can review the electrical requirements, check the panel, and decide whether the existing service has enough capacity.

We often see problems when the electrical review is left until the condenser is sitting on the pad. Common issues include no spare breaker spaces, an old panel with unclear labelling, a disconnect mounted in the wrong location, undersized existing wiring from a previous AC unit, or a finished basement ceiling blocking the route from the panel to the outdoor wall.

You should book an electrical review if:

• You are replacing an older air conditioner with a heat pump
• You are adding a ductless mini-split to a bedroom, garage, office, or addition
• The HVAC contractor says the unit needs a new 240V circuit
• Your existing outdoor disconnect is corroded, loose, or not rated for the new equipment
• Your panel is full or has tandem breakers already installed
• You are adding auxiliary heat, an air handler, or multiple outdoor heads
• The condenser is moving to a new side of the house

Heat pumps can have different electrical demands than the old AC unit they replace. A straight like-for-like swap may still need a different breaker, disconnect, or conductor size if the manufacturer’s nameplate calls for it. If the existing circuit cannot be reused safely, we install a new one rather than forcing the new equipment onto old wiring.

For outdoor wiring that is separate from HVAC, such as receptacles, holiday lighting, or landscape equipment, see our outdoor outlets and holiday lighting circuits page.

ESA permits and OESC rules are part of the job

HVAC electrical work in Ontario must follow the Ontario Electrical Safety Code and the equipment manufacturer’s instructions. Where required, City Power files the ESA notification, performs the work, and arranges inspection. We are a Licensed Electrical Contractor, ECRA/ESA #7015314.

The ESA inspection is not just a paperwork step. The inspector may check that the circuit is correctly sized, the breaker matches the equipment nameplate, the outdoor disconnect is suitable and accessible, wiring methods are weather-rated, bonding is correct, and the panel has been labelled. If a finished area is involved, the inspector may also want access before everything is closed.

For heat pumps and AC units, the outdoor disconnect matters. It gives service technicians a visible means to shut power off at the condenser. It must be installed in a practical location, protected from damage, and wired with outdoor-rated materials. We coordinate with the HVAC contractor so the disconnect and whip land where the condenser will actually sit, not where it is convenient for only one trade.

If an ESA inspection, insurance request, or real estate transaction requires documentation after electrical work, our ESA electrical safety certificate page explains that process. If existing HVAC wiring has already been flagged by an inspector, see electrical code corrections and ESA defect repairs.

In condos, townhomes, rentals, and multi-unit buildings, there may also be building rules, board approval, firestopping requirements, or access restrictions. We can work from the HVAC specification and the property’s electrical room information, but management and utility requirements must be confirmed before installation.

The visit checks the route, the panel, and the real cost

We start with the equipment information if you have it: make, model, voltage, MCA, MOCP, location of the indoor and outdoor units, and whether the HVAC contractor is supplying the disconnect or expects us to. If you do not have the nameplate data yet, we can still inspect the panel and likely cable route, then finalize the quote once the equipment is selected.

On site, we check:

• Main breaker size and panel condition
• Available breaker spaces and compatible breakers
• Existing HVAC circuit size and condition
• Route from panel to outdoor condenser
• Finished walls, ceilings, joists, brick, and exterior penetrations
• Distance to the unit location
• Whether trenching, conduit, or exterior routing is needed
• Any signs of overheating, double-tapping, corrosion, or amateur wiring

A straightforward HVAC circuit is usually faster when the panel is in the basement near the condenser wall. It becomes more involved when the panel is on the opposite side of the house, the basement is fully finished, the outdoor unit is remote from the building, or the panel has no safe capacity left.

Pricing depends on circuit amperage, distance, access, disconnect type, and whether panel work is needed. For HVAC controls, condensate pumps, or related equipment, a standard 20A dedicated circuit from the panel usually runs $250–$500, based on the run length and wall finishes along the path. Heavier 30A–50A circuits run $400–$900. If the home needs a 100A-to-200A panel upgrade, that typically costs $3,200–$4,500 including the panel, labour, ESA permit, and inspection. If the scope is not one of those published bands, we quote it in writing after a site visit.

City Power provides free written estimates, full cleanup, and 24/7 emergency service across Toronto and the GTA, including North York, Scarborough, Etobicoke, Mississauga, Brampton, Markham, Vaughan, Richmond Hill, Oakville, Burlington, Pickering, Ajax, Whitby, Oshawa, Barrie, and nearby communities. You can also browse our electrical services hub for related work.