Furnace Replacement in Greensburg, PA: What to Expect

A furnace replacement in a Greensburg-area home is a one-day project for most properties — but what happens during that day matters a great deal for how the system performs over the next 15–20 years. Here is what the process looks like when it is done properly.

Step 1: Assessment and sizing

Before any equipment is selected, a technician should assess the home's actual heating load. This means looking at insulation levels, window area, ceiling height, air leakage, and the existing duct system — not just the size of the furnace being replaced. An oversized furnace short-cycles, which reduces comfort and efficiency. An undersized furnace struggles on the coldest days. Proper sizing requires a load calculation, not a guess.

Step 2: Equipment selection

Once the load is established, the right equipment can be selected. For most Greensburg-area homes, a high-efficiency gas furnace in the 96% AFUE range makes sense — the climate justifies the efficiency investment, and the fuel savings over the life of the equipment are real. Two-stage and variable-capacity furnaces offer better comfort than single-stage units by running longer at lower outputs rather than blasting on and off.

Step 3: Installation day

On installation day, the old equipment is disconnected and removed. The new furnace is set in place and connected to the gas supply, electrical, flue, and ductwork. Venting is a critical step — high-efficiency furnaces use PVC flue pipes rather than metal flue, and the routing must be done correctly to prevent condensate issues and ensure proper combustion air supply.

After installation, the technician commissions the system: verifying gas pressure, checking combustion, testing all safety controls, confirming airflow, and setting the thermostat. A properly commissioned furnace runs at the efficiency it was designed for from day one.

What to expect after installation

A new furnace should run quietly, heat the home evenly, and cycle on and off at a reasonable frequency. If you notice short cycling, unusual noises, or rooms that are not reaching temperature, call your installer — these are signs that something in the installation or setup needs attention.

Heirloom Mechanical installs and replaces furnaces throughout Greensburg and the surrounding Westmoreland County area. We carry PA HIC No. PA196206 and are fully insured. Call 412-889-6800 for a free estimate.