Furnace Not Turning On? What to Check Before You Call in Berks County

If your furnace isn't turning on tonight, check four things first: the thermostat, the furnace's own switch and breaker, the filter, and the furnace door. Any of those can stop a furnace with nothing broken. If it still won't run, write down how its light blinks and call; that plus what you checked is what the company needs to hear.

If you smell gas, skip all of that: leave, get at least a football field away, and call UGI at 800-276-2722 or 911 from there. Don't flip a switch or use your phone inside; either can make a spark. The visit is free, and you don't go back in until UGI says so.

If a carbon monoxide alarm is sounding, or people in the house have headaches and feel sick like the flu with no fever, go outside and call 911. Don't go look at the furnace first.

The checks below take five minutes, and the county's HVAC contractors are on one page for when you're done; they'll want to hear what you checked.

Check the thermostat, the furnace switch and the breaker before anything else.

The thermostat has to be on Heat, with the number set above what the room is right now, or the furnace has no reason to start. Put fresh batteries in if it takes them, and write down any error code it shows.

The furnace's own power switch looks like a light switch on the side of the furnace, on a nearby wall, or on a ceiling joist. Make sure it's on.

Then open the breaker box, the grey or green metal door in the basement or garage, find the tripped switch and toggle it back on. If it trips again, stop, because a breaker that keeps tripping is an electrical problem, and that means a call.

Write down the blinking light on the furnace before you open anything.

There's a small light behind a little window in the furnace's front panel, and it blinks a flash code, a repeating count of flashes that names the fault. Count it before you open the door, because opening the door cuts the power and the code with it.

A slow green blink means the furnace is fine and idle. Red flashes in a repeating count are the furnace naming its problem, and the legend inside the furnace door says what each count means.

Write the color and the count down. Some faults make the furnace stop trying for about an hour before it tries again on its own, so a silent furnace may start up while you're on the phone.

Furnace blowing cold air or short cycling? Change the filter and put the door back on.

A furnace that runs briefly, shuts off, and starts again soon after is short cycling: it's turning on and off before the house gets near the temperature you set. The cause you can fix yourself is a clogged filter.

A clogged filter starves the furnace of air. The furnace overheats, a safety shuts the burners off, and the blower keeps pushing the cold air you feel. Once it cools down it lights again, and the cycle repeats.

A couch or drapes over a return grille, the big vent that pulls room air back into the furnace, does the same thing, so move them.

Pull the filter out. If it's packed with dust, replace it, check it every four weeks, and never run the furnace without one.

Then push the door on until it seats, because the door presses a switch that cuts all power the moment it's off, and a furnace that died right after a filter change may just need that door pushed back on.

Furnace not igniting? What to look at, and the one reset you get.

Older furnaces keep a pilot light burning, a small flame that's always lit and lights the burners on demand. If yours has one, the lighting instructions are on the furnace itself. Follow them only when there's no smell of gas, and if the pilot won't stay lit, that's the call.

Newer furnaces have no pilot. An igniter, a small part that heats up glowing hot to light the gas, does that job, so never put a match to a modern furnace's burners. A failed igniter is the technician's, and so is anything on the gas side of the furnace, valves included. Leave all of it alone.

On propane, look at the tank gauge first. If it ran dry, the delivery company or a technician leak-checks the system before the gas goes back on.

On oil, check the tank. If you smell oil or see any around the burner, don't press anything, because that's the call. Otherwise press the burner's reset button once, and if it doesn't catch, stop: every try sprays more oil into the chamber, and unburned oil in there can flash back at the next start.

Heat quit after a snowstorm? Check the two pipes on the outside wall.

A high-efficiency furnace, the kind with two white plastic pipes out a side wall instead of a chimney, breathes through those pipes and shuts itself down when snow drifts over them. That's the carbon monoxide protection working: it won't run when it can't push its exhaust outside.

Trace the pipes from the furnace to the wall, find them outside, and clear the snow by hand with a broom or a shovel. Don't use salt, hot water, or a snow blower on the pipes or the gas meter.

What a furnace service call costs in Berks County, and what to say on the phone.

Here's what a heat visit costs at three companies that serve Berks, as of 2026.

Company (town)	The visit	Price
MDT Heating and Air Conditioning (Honey Brook)	Heat diagnostic, report included	$129
Clark's Heating & Cooling (Reading)	Heating repair booking, 90 minutes	$150
Real Airflow Heating & Cooling (Fleetwood)	Diagnostic call, when you go ahead with the repair	$0

A daytime visit runs $129 to $150 on its own, or nothing when a company folds it into the repair. The fuller list is in what an HVAC contractor charges per hour in Berks County.

The table is daytime prices. Your furnace quit tonight, so the figure to ask for on the phone is the after-hours rate.

The county's HVAC contractors are on one page, and Berks Plumbing & HVAC Specialist in Reading is on it. A company that works on the furnace and the water lines both is a fit for a house that's been cold for hours.

Ultimate Comfort Heating & Cooling in Wernersville runs extended hours with no overtime fee, which is the answer you're hoping for when you ask.

Have the brand and model from the label, the light's color and flash count, what you checked, whether it burns gas, propane or oil, and whether the pipes go out a side wall. Those five things turn a vague no-heat call into a job someone can price and schedule.

Then ask four questions before you say yes: the diagnostic fee, the after-hours rate tonight in dollars, whether the fee comes off the repair if you go ahead, and when they can be there. Tonight and tomorrow morning may be priced differently, so ask which you're booking.

A baby or someone over 65 in the house and no way to keep the house warm tonight means stay somewhere else and sort the furnace in the morning. While you wait, open the cabinet doors under sinks on outside walls and let a cold tap drip so the pipes don't freeze.

If the repair is out of reach, Pennsylvania's Low Income Home Energy Assistance Program, LIHEAP, has a Crisis grant, and a broken furnace counts. It pays up to $1,000 through the county assistance office, opens November 2, 2026, and should run to April 23, 2027. Our post on help paying for heating in Berks County shows how to apply.

Questions Berks homeowners ask when the furnace won't start.

How do I reset my furnace?

The first reset is waiting: after some faults the furnace stops trying for about an hour, then tries again on its own. Beyond that you get one try at each: a tripped breaker, the oil burner's button, a pilot light. If it happens again, that's the furnace telling you to call.

Why does my furnace keep turning on and off?

The causes of short cycling split in two. Yours are a clogged filter, a blocked return grille, and a thermostat in a bad spot. The technician's are the overheat safety, a cracked heat exchanger (the metal chamber the burners heat and your air passes over), and, most often of all, a furnace that's too big for the house.

Will UGI fix my furnace?

UGI comes out free for a gas smell and checks the gas; that's the whole visit. The furnace is yours, so the repair is an HVAC contractor's job and a separate call. A separate company that works under the UGI name, UGI Heating, Cooling & Plumbing in Reading, is one of the furnace repair companies on the county's HVAC page.

Is it worth fixing an old furnace tonight?

Tonight the job is heat, so get the diagnosis and the price. Repair or replace is a daylight decision; our post on the repair-or-replace rule for HVAC in Berks County walks through it, with furnace replacement cost in Berks County as the number to hold a big repair against.

Sources

• UGI Utilities, "Natural Gas Safety: Leak Detection" (read September 5, 2026): leave and get a football field away, call 800-276-2722 or 911 from a safe distance, cell phones can spark, no charge to investigate an odor, don't re-enter until inspected.
• UGI Utilities, "Does UGI install the natural gas equipment or only the gas service?" (read September 5, 2026): UGI installs only the gas service line; furnace equipment is bought and installed through an HVAC contractor.
• U.S. Consumer Product Safety Commission, "Carbon Monoxide Questions and Answers" (read September 5, 2026): symptoms similar to the flu but without the fever; get outside to fresh air, then call 911.
• Carrier, "Condensing Gas Furnace Owner's Manual, OM9GFC-08" (January 2018): thermostat on Heat and above room temperature; power switch and breakers; a dirty filter overheats the furnace and shuts it down; check the filter every four weeks; never run without a filter; record the light's code before opening the door; the code legend inside the furnace door; the igniter on a modern furnace and never lighting the burners by hand; don't touch a switch or use a phone inside if you smell gas; blocked return grilles; vent and intake pipes unobstructed in all seasons.
• Trane, "Furnace Not Turning On?" (read September 5, 2026) and Trane, "Furnace Not Blowing Hot Air?" (read September 5, 2026) (the second only for fuel in a propane or oil tank): the switch on the furnace, a nearby wall or a ceiling joist; the grey or green breaker box; a breaker that trips again is an electrical issue; thermostat batteries and error codes; gas supply and valve issues are for the technician; pilot light on older furnaces, electronic ignition on newer ones; keep registers and returns clear.
• Johnson Controls / York, "TM9V Installation Manual" (read September 5, 2026): the blower door switch cuts all power when the panel is off; how flash codes are counted; slow green is normal; four red flashes means the overheat safety opened, check the filter first, and the control waits one hour before retrying; three red flashes points at a blocked vent pipe.
• Trane, "Furnace Short Cycling" (read September 5, 2026): the definition; filters, blocked returns and thermostat placement on the homeowner's side; the overheat safety, a cracked heat exchanger and an oversized furnace, the most common cause, on the technician's side.
• Pennsylvania Propane Gas Association, "Important Propane Safety Information" (read September 5, 2026): don't run out of gas; a leak check by the retailer or a qualified technician before the gas is turned back on.
• R.W. Beckett, "AFII Oil Burner Instruction Manual" (read September 5, 2026) and R.W. Beckett, "GeniSys 7505 Burner Control Manual" (read September 5, 2026): the control stops retrying so oil does not pile up in the chamber, and never start the burner when excess fuel or vapor has accumulated in the appliance, because of puffback.
• New York State Office for People With Developmental Disabilities, "Health and Safety Alert: Keep Obstructions Away from Venting Systems" (January 2020): snow over side-wall vent pipes trips the furnace's built-in safety and leaves you without heat; a blocked vent can build carbon monoxide; trace the pipes and clear them.
• UGI Utilities, "Winter Meter Safety" (read September 5, 2026): clear exterior vents and the meter by hand with a broom or shovel; never a plow, snow blower, salt, hot water or ice-melting chemicals.
• MDT Heating and Air Conditioning, "Services" (read September 4, 2026): heat diagnostic $129, report included.
• Clark's Heating & Cooling, "Book Online" (read September 4, 2026): heating repair, 1 hour 30 minutes, $150.
• Real Airflow Heating & Cooling, "Specials" (read September 4, 2026): $0 diagnostic service call with any repair.
• Ultimate Comfort Heating & Cooling, home page (read September 4, 2026): extended service hours with no overtime fee.
• Pennsylvania Department of Human Services, "Apply for the Low Income Home Energy Assistance Program (LIHEAP)" (read September 5, 2026): broken heating equipment needing repair or replacement counts as a Crisis emergency; how to apply.
• Pennsylvania Department of Human Services, "2026-2027 LIHEAP Vendor Guidelines" (August 2026): season begins November 2, 2026 and is expected to end April 23, 2027; Crisis season maximum $1,000 per household; requests go through the county assistance office.
• U.S. Department of Health and Human Services / Centers for Disease Control and Prevention, "Extreme Cold: A Prevention Guide to Promote Your Personal Health and Safety" (2005): infants must not sleep in a cold room and the household should stay elsewhere if the home can't be kept warm; people over 65 are more susceptible to cold.
• American Red Cross, "Preventing and Thawing Frozen Pipes" (read September 5, 2026): let cold water drip from a faucet served by exposed pipes; open kitchen and bathroom cabinet doors.