You have signed the quote and the install is on the calendar. Here is what furnace installation day actually looks like, what to do beforehand, and what you should get before the crew leaves.
If you are wondering how to prepare for HVAC installation, most of it comes down to access and timing.
Clear the path and the work area. The crew needs to move old equipment out and new equipment in. Clear the route from the entry door to the furnace, and give two or three feet of open space around the unit. Move storage bins, paint cans and anything stacked against the equipment.
Secure pets. Doors will be propped open for stretches and there will be tools on the floor.
Plan to be home. An adult 18 or older needs to be present for the whole visit. There will be questions, and there is a walkthrough at the end you want to be part of.
Expect the heat to be off for a while. In shoulder season this is a non-issue, which is one more argument for replacing in September rather than January.
Know where the shutoffs are. Gas and electrical. You will not need to touch them, but it is worth knowing.
Have your paperwork handy. Quote, any financing documents, and if there is a rebate application involved, whatever the program requires. Current program details are in Michigan HVAC rebates in 2026.
On furnace installation day, before anything is disconnected, floor coverings go down along the work path and in the work area. Items blocking access are moved or protected.
This is not a courtesy detail. A furnace changeout involves carrying heavy equipment through a house, and the difference between a crew that protects your floors and one that does not shows up on your stair treads.
The furnace replacement process starts with removal. The old furnace is shut down, disconnected from gas and electrical, and separated from the venting and ductwork. If there is an air conditioner or heat pump coil coming out at the same time, refrigerant is recovered properly rather than vented, which is a legal and environmental requirement under EPA Section 608.
The old equipment is carried out and loaded for proper recycling. It does not stay in your basement.
Setting the unit. The new furnace is positioned, leveled and secured.
Ductwork transitions. The supply plenum and return connections are fabricated or modified to fit. This is where sheet metal work matters — a sloppy transition leaks air and costs efficiency for the life of the system.
Venting. On a high-efficiency condensing furnace, PVC intake and exhaust are routed to an exterior wall with proper slope and termination clearances. On an 80 percent unit, the metal flue connection is made and checked.
Gas connection. New piping and connections as needed, with a leak check.
Condensate. On a condensing furnace, a trap and drain line with proper fall, and a pump if gravity drainage is not available.
Electrical. Circuit, disconnect and control wiring.
Thermostat. Connected and configured for the equipment type. If it is a heat pump or dual fuel system, the changeover configuration is set here.
The part that separates a finished job from a job that merely turns on.
Gas pressure verified at the manifold against specification. Temperature rise measured and compared against the data plate range. Airflow verified and blower speed adjusted if needed. Safety controls tested — limit, rollout and pressure switches. Combustion checked. Venting confirmed to be drafting correctly.
Every furnace replacement process should end with these readings, and you should be told what they came out to. On our visits you get the readings, which gives you a baseline for future service.
Before the crew leaves on furnace installation day, you should get:
Where the filter goes, what size it is and how often to change it. Our filter guide covers the details, and you can order online.
How the thermostat works, including anything new about it.
Where the shutoffs are.
What normal sounds like for this equipment, so the first startup noise does not worry you.
Model and serial numbers, and confirmation of whether warranty registration is handled for you. This matters — see our furnace warranty guide for why the registration window is worth tracking.
Any paperwork for permits, inspection or rebates.
At the end of furnace installation day, protective coverings come up, tools and packaging go out, and the work area is left clean. Old equipment leaves with the crew.
A dusty burning smell on the first few cycles is normal on a new installation as manufacturing residue and settled dust burn off. It should fade within a day of normal operation. If it persists, or if you notice anything other than a dusty smell, our guide on furnace smells covers what each one means.
Different sounds. New equipment sounds different, especially if you went from single-stage to two-stage or modulating. Longer, quieter run cycles are the system working as designed.
Different airflow. If ductwork was modified, the balance between rooms may have changed. Give it a week, then say something if a room is not right.
J&J has installed heating systems across Battle Creek, Marshall, Coldwater and the surrounding towns for over 50 years. Furnace replacement estimates are free.
A straightforward changeout is typically one day. Projects involving venting changes, duct modification or a switch to a different system type can run longer, and you should be told which before the day.
Yes. An adult 18 or older needs to be present for the visit, and you want to be there for the walkthrough at the end.
The heat is off while the work is underway. In mild weather it is barely noticeable, which is one of the better reasons to schedule a replacement in fall rather than mid-winter.
Installation coming up, or thinking about scheduling one? Call J&J at (269) 965-1627 or schedule a visit today.
9000 M-66 South • East Leroy, MI 49051
(269) 965-1627
Monday - Friday: 8:00am - 5:00pm
