By the WY&G, Inc. team: licensed HVAC contractor, CSLB C-20 #1044922, over 25 years and thousands of customers in the Santa Clarita Valley and Orange County.
Before the technician arrives
- Clear a path to the furnace, whether it's in a closet, the garage or the attic.
- Note anything odd from last winter: noises, smells, cold rooms, short cycling.
- Have the thermostat working and set to Heat.
- Find your CO alarms. It's a good time to test them.
Safety checks
- Heat exchanger. A visual inspection, with a camera where access allows, for cracks, rust and holes.
- Venting and draft. The vent pipe is connected, sloped right and clear, and exhaust actually leaves the house.
- Carbon monoxide. A combustion reading in the flue, and a check of the air at the supply vents.
- Gas connections. A leak check at the furnace connections.
- Safety switches. The high limit, flame rollout and pressure switches are tested to make sure they actually shut the furnace down when they should.
Burners and ignition
- Flame sensor cleaned and the flame signal measured.
- Igniter inspected for cracks and tested.
- Burners cleaned if needed, and the flame checked for a steady blue pattern.
- Gas pressure measured and compared to the manufacturer's spec.
A dirty flame sensor is the most common reason a furnace lights and shuts off. Catching it during a tune-up beats finding it on a cold night.
Airflow and blower
- Filter checked or replaced, and the right size confirmed.
- Blower wheel and motor inspected. Motor amp draw measured.
- Capacitor tested on furnaces that use one.
- Temperature rise measured: the difference between return air and supply air, compared to the range on the furnace label. Too high or too low means an airflow or gas problem.
- Static pressure where it makes sense, to see if the ducts are choking the system.
Electrical and controls
- Wiring connections tightened, burned or loose terminals noted
- Transformer voltage checked
- Control board fault history read, if the board stores it
- Thermostat tested through a full heating cycle
- Door safety switch checked
Drain on high efficiency furnaces
Furnaces with white plastic vent pipes make water. The trap, drain lines and condensate pump (if there is one) get checked and flushed. Many share a drain with the AC, so summer sludge can stop the heat in winter. It's one of the easiest problems to prevent.
Heat pumps get their own list
For a heat pump, the visit also covers the defrost cycle, the reversing valve, the outdoor coil and fan, electric backup heat strips, and refrigerant operating readings taken by a certified technician. It's not a top off: if the charge is low, there's a leak, and the leak is what needs fixing.
What a tune-up does not fix
A tune-up keeps a healthy system safe and running well. It won't fix design problems. Leaky or undersized ducts, a single small return, a furnace sized wrong for the house, or rooms that were never part of the duct layout all need their own solutions. A good technician will point these out with the readings to back it up, so you can decide later. And if the inspection finds a cracked heat exchanger, that's a repair or replacement conversation, not part of the tune-up.
Signs you need a repair visit, not just a tune-up
- The furnace already short cycles, bangs or smells
- Your CO alarm has gone off
- Rooms stay cold no matter what the thermostat says
- It locked out at least once last winter
Tell us when you book, so we plan time for diagnosis.
When to schedule it
Fall is ideal, before the first real cold night. In the Santa Clarita Valley that usually means October or early November. Toward the Antelope Valley, where nights get cold sooner, schedule a bit earlier. And if you missed fall, a tune-up in winter is still far better than none.
What you should get afterward
You should know what was checked, what the readings were, and what, if anything, needs attention, with photos when there's a problem. Recommendations should be explained, not pushed. That's how we do it at WY&G. We're a licensed HVAC contractor (CSLB C-20 #1044922) with over 25 years in the area.
See heating tune-up and safety check, maintenance in Santa Clarita and our maintenance page, or heater repair in Santa Clarita. Call (323) 240-2373 or book online, and use code WEB25 for $25 off (coupons).
