Furnace Not Heating? What Inland Empire Homeowners Should Check First

Quick safety first

Before you open panels or dig into the unit:

• If you smell gas (a rotten-egg odor), leave the home and call your gas utility or 911 from outside. Do not flip switches or use phones inside.
• If the furnace cabinet is unusually hot, or you see scorch marks, shut the system off at the thermostat and the breaker and call for service.
• Never ignore a carbon monoxide detector that is alarming. Fresh air and a professional check come first.

Those situations are not DIY. For everything else below, you are only looking for simple resets and obvious issues.

Thermostat and power checks that fix a surprising number of “no heat” calls

1. Confirm the thermostat mode. It should be set to Heat, not Cool or Off. Raise the setpoint a few degrees above room temperature and wait a minute.
2. Replace weak batteries. A blank or flickering display is a common culprit on battery-powered thermostats.
3. Check the furnace switch. Many furnaces have a light-switch-style shutoff on or near the unit. Make sure it is On.
4. Check the breaker. Look for a tripped breaker labeled furnace, air handler, or HVAC. Reset once. If it trips again, stop and call — do not keep resetting.
5. Look at the filter. A packed filter can cause overheating and short cycling. If it looks gray and clogged, replace it with the correct size.

If the system starts after these steps, great — still consider a fall furnace tune-up so you are not fighting the same issue mid-season.

What “blowing cold air” usually means

If the blower runs but the air is cool:

• The burners may not be lighting (ignition, flame sensor, or gas supply issues).
• A high-limit switch may have opened because of airflow problems (dirty filter, blocked return, closed vents).
• On heat pumps, the system may be in a brief defrost cycle — but long stretches of cold air still deserve a look.

Do not keep running a furnace that cycles on and off every minute or two. Short cycling wears parts and rarely fixes itself. Our heating repair team diagnoses the root cause on site.

When a seasonal tune-up helps

Filters load up over dry months, and ignition parts sit unused through the cooling season. A system that worked fine in spring can struggle when heat is needed again. That is why a seasonal check pays off. Henley’s offers a $99 furnace tune-up (the 16-point furnace check). An AC tune-up is also $99. HVAC estimates are free. On HVAC repair visits, the diagnostic is $59 and is waived when you approve the repair. Estimates are valid for 14 days.

We serve homes across our service area, including Corona customers on our Corona heating & air page.

When to stop troubleshooting and call

Call a licensed pro if:

• You completed the basic checks and still have no heat.
• The furnace starts then shuts down repeatedly.
• You hear grinding, screeching, or loud booming.
• You see water around a high-efficiency furnace (condensate issues).
• Anyone in the home is sensitive to cold and you cannot wait on DIY experiments.

You do not need to guess the part name before you call. Describe what you notice — no heat, cold air, odd smells, error lights — and we will take it from there.

What a Henley’s heating visit looks like

1. We confirm the complaint and check thermostat, power, and airflow.
2. We inspect ignition, burners, safety switches, and (when applicable) heat exchanger concerns that affect safe operation.
3. We explain options in plain English before any repair work.
4. You decide.

Family-owned for more than 40 years since 1983. Our corporate office is at 1701 Commerce St, Corona, CA 92878, with a local branch near you, and our teams serve homes across the Inland Empire and into Orange County.

Simple habits that keep heat reliable

• Change filters on schedule (often every 1–3 months during heavy use).
• Keep returns and supplies open — closing most vents “to save energy” can backfire.
• Clear storage from around the furnace closet or attic unit.
• Request maintenance before the coldest weeks, not during them.
• Financing available through Fastlane.

We install and service major brands such as Goodman, Trane, Rheem, Ruud, Carrier, and American Standard, along with many others. If replacement becomes the smarter path, we also handle heating installation with free HVAC estimates.