Lennox Furnace Replacement in a Crawl Space in Innisfil

Furnace Replacement, Innisfil

An Old Furnace Out, a New Lennox In, Lying Flat in a Crawl Space

In this Innisfil home, the furnace sits in a crawl space, under the floor joists, with very little room to move. We took the old gas furnace out and replaced it with a new Lennox high-efficiency gas furnace, installed horizontally so it fits the space and lines up with the ductwork the house already had.

• Job: Gas furnace replacement
• Equipment: Lennox high-efficiency natural gas furnace
• Setup: Horizontal installation in a crawl space
• Location: Innisfil, Ontario
• Completed: October 2026

Delivery Day

The New Lennox Arrives

The furnace came to the house boxed, on a hand truck, straight off our van. Getting it from the driveway to its spot under the floor was part of the job, because a crawl space leaves no room to tip, turn or reposition a large unit once it’s inside.

That’s why the planning happens before anything gets carried in: where the furnace will sit, which way it faces, and how the ducts, venting and gas line will meet it.

The Challenge

Working in a Restricted Crawl Space

Limited clearance and awkward access made this more involved than a standard furnace swap. Once the existing furnace was removed, our team positioned the new Lennox horizontally beneath the floor structure and connected it to the home’s existing supply and return air ductwork.

The connections had to change to suit the new unit. We replaced and modified the PVC exhaust venting, then rerouted and reconnected the natural gas supply line to the furnace. Positioning, gas piping, venting and access to the equipment all had to be worked out together, since each one affects the others in a space this tight.

The Result

New Thermostat, Then Every Check

The carton label shows the model, a Lennox ML297UH045XV36BK. With the furnace in place, we installed a new thermostat and ran final operation and safety checks before calling the job done.

Project summary: a residential gas furnace replacement in Innisfil, Ontario, completed in October 2026. North Wind HVAC removed the existing gas furnace and installed a new Lennox high-efficiency natural gas furnace horizontally in a restricted crawl space, connected it to the existing supply and return ductwork, replaced and modified the PVC exhaust venting, rerouted and reconnected the natural gas supply line, installed a new thermostat, and completed final furnace operation and safety checks.