10.2 Mechanical Systems: HVAC, Electrical & Plumbing
Key Takeaways
Check the appliance nameplate, approved venting, design loads, equipment and service records.
HRVs exchange heat, while ERVs also exchange some moisture between the airstreams.
Electrical service size, conductor material and circuit protection answer separate questions.
Confirm suspected Poly-B with markings or qualified inspection. Ask the insurer about the specific installation.
Identify systems and verify the applicable code
Heating, ventilation, electrical distribution and plumbing serve different functions and often interact. Replacing a gas appliance can affect a shared vent. Adding electric space heating or vehicle charging can affect service capacity. In November 2026 Alberta lists the 2024 Canadian Electrical Code, Part I (effective April 1, 2025), the National Plumbing Code of Canada 2020 (effective April 1, 2023) and CSA B149.1:25 for natural gas and propane installations (effective March 1, 2026). Check the rules applicable to the permit and installation date, plus current requirements for proposed work. Ask for equipment data, permits, inspection records, and service or replacement invoices. Condition, permit status and insurer acceptance each need their own evidence.
Identify heating, cooling and ventilation
A forced-air furnace heats air and distributes it through ducts, while return ducts bring air back. A gas condensing furnace recovers additional heat as water vapour in the flue gas condenses. AFUE expresses seasonal fuel-use efficiency. Some sealed-combustion condensing furnaces use separate outdoor air intake and exhaust pipes and have a condensate drain. Vent materials, routing, slope and terminations must suit the listed appliance, instructions and applicable gas code. Plastic pipe or a capped chimney alone does not establish the furnace efficiency or a compliant installation. If a water heater still shares or depends on a vent affected by a furnace replacement, have a gas professional check the remaining configuration.
An air-source heat pump transfers heat from outdoor air to the home in heating mode and reverses the cycle for cooling. A ground-source system exchanges heat with the ground through its loop. Capacity and efficiency depend on conditions and the selected equipment. Compare design heat loss and the unit’s output at the local design temperature before deciding whether supplemental heat is needed. A hydronic system circulates heated water through radiators, fan coils or in-floor tubing. Identify the heat source, distribution, zones and service needs. Ask for design and commissioning information if a renovation changed the loads or equipment.
A heat recovery ventilator (HRV) exchanges heat between incoming and outgoing air streams. An energy recovery ventilator (ERV) also transfers some moisture between streams. Ask about outdoor and exhaust terminations, filters, airflow and balance. Ventilation can help manage indoor moisture and pollutants. It does not repair a leak or establish safe radon levels. For a suite or a tighter envelope, have a qualified professional assess ventilation and any combustion-air interaction.
Compare fireplaces
| Style | Operating difference | What to verify |
|---|---|---|
| Open wood-burning masonry fireplace | Burns wood in an open firebox and uses a chimney to exhaust smoke. It can draw heated room air up the flue. | Check the hearth, firebox, damper and chimney with a qualified inspector. Ask the insurer what documentation it requires. |
| Enclosed wood-burning insert | Fits into an existing opening and burns wood in a closed appliance. It still relies on an approved venting installation. | Check the appliance label, applicable liner or chimney, clearances and the records of permit and inspection. |
| Direct-vent gas fireplace or insert | A sealed system draws combustion air from outdoors and exhausts combustion products outside. The two paths may be concentric. | Check the gas appliance, vent configuration and termination with a gas professional. An older gas appliance may use a different venting design. |
| Electric fireplace | Uses electricity for flame effects and, on some models, heat. It has no fuel combustion at the unit. | Confirm the intended heating output, circuit capacity and installation instructions. Ask about electrical permit requirements if wiring will change. |
A buyer who wants to reuse an old chimney for a gas insert should have the installer confirm the approved venting and check the required permits before relying on the existing masonry. The appliance and proposed installation determine which records and specialist checks matter.
Alberta permits · Alberta solid-fuel appliance guidance · NRCan gas fireplace guidance
Distinguish service capacity, wiring and circuit protection
The service brings power from the utility to the panel. The ampere rating matters alongside the calculated load, main equipment, conductors and intended additions. A visible panel label or spare breaker space alone cannot establish capacity. If a buyer plans a heat pump, suite or EV charger, ask an electrician to calculate the load and verify any upgrade with the permit authority and utility. The insurer may request evidence for a specific installation. Obtain its written requirements before relying on coverage.
Aluminum branch wiring and older knob-and-tube wiring warrant identification and professional review. Overheating or damaged connections are warning signs. For aluminum branch conductors, an electrician can assess the full circuit and use a compliant repair such as copper pigtails with connectors approved and marked for the exact aluminum-to-copper combination, where permitted. Product markings, conductor size, the applicable code and manufacturer instructions determine the method. Have the electrician document the work and confirm separately whether the insurer accepts it. Buyers and licensees should avoid opening energized equipment.
| Protection | What the device responds to |
|---|---|
| Ordinary breaker | Overcurrent, such as overload or a short circuit |
| Ground-fault circuit interrupter (GFCI) | Current leakage to ground, which can cause electric shock |
| Arc-fault circuit interrupter (AFCI) | Qualifying electrical arcing, which can start a fire |
Check protection at the applicable circuits under the relevant code. A listed combination device may provide both ground-fault and arc-fault protection.
Separate water supply, waste and water heating
Pressurized supply piping distributes potable water. Copper is rigid metal, while PEX is flexible cross-linked polyethylene. Polybutylene (Poly-B) is another flexible plastic commonly identified by markings and often grey. Colour and construction date are clues. Check material, fittings, evidence of leakage and any documented replacements. Alberta’s Poly-B guidance identifies installation and operating conditions that can affect service. A plumber can assess the property. The buyer’s insurer can confirm whether it will cover the installation and under what terms. The pipe type by itself does not establish a known material latent defect.
Drains carry wastewater to an approved sewer or private system. Traps hold a water seal, while vents help control pressure and protect those seals. Recurring backups or sewer odours justify a plumber’s assessment. A sewer scope can check accessible portions of the building sewer for defects such as roots or damage. Verify the scope and responsibility for repairs.
A storage water heater keeps a reserve of hot water. A tankless unit heats water as it flows, within the unit’s rated capacity. Ask about sizing, heat source, venting, service history and manufacturer maintenance. With a gas appliance, check the current installation and vent approval instead of inferring it from appearance. With any unexpected plumbing or heating finding, give the client the facts, identify the appropriate trade and review the signed inspection, insurance or financing deadline before acting on it.
A home inspector sees flexible grey supply piping in a 1989 Red Deer house. The fittings and pipe markings have not been examined. What should the buyer’s licensee advise?
Treat the colour as proof the piping is modern PEX and qualify the buyer for a lower premium.
Assume the Alberta Safety Codes Act guarantees lifetime replacement.
End the transaction because Alberta prohibits the sale of any home with plastic pipe.
Confirm material and condition through inspection or a plumber, check the buyer’s coverage and review the applicable contract conditions.
A 1971 home has confirmed aluminum branch wiring. The insurer asks for an electrician’s report. Which repair approach can the electrician evaluate if the connection and applicable code permit it?
Wrap the terminations with household tape and increase the breaker rating.
Use copper pigtails with connectors approved for the exact aluminum-to-copper conductors, following the applicable code and instructions.
Seal the outside of the receptacles with silicone to keep air away from the wiring.
Fit a larger fuse so a loose connection continues carrying current.
A furnace label and manual identify a two-pipe, sealed-combustion condensing gas furnace. The installer confirms the pipes are its outdoor air intake and combustion exhaust. Why can this design recover more heat from the fuel?
Its intake pipe brings heat directly from the water heater’s flue into the house.
Its exhaust pipe circulates water through the room radiators.
The furnace recovers additional heat as water vapour in its flue gas condenses.
The furnace stores its combustion gases indoors until the next heating cycle.
Sections you finish are checked off in the contents.