A furnace that will not light needs a diagnosis before a replacement decision. Ignition, flame sensing, airflow and control faults can interrupt heating. Mora Home Services reads the fault code and verifies the cause with testing. A safety shutdown needs attention. You receive a written price before any repair begins.
10 Years in Business 20 Years Trade Experience Family-Owned 8 AM to 7 PM, every day.
A furnace lockout is a control response that stops operation after specified faults or failed ignition attempts. It identifies a condition to investigate, not proof that the furnace is safe to keep resetting.
What Furnace Repair Covers
A furnace that will not light may have a repairable fault. A control or safety shutdown needs investigation before the furnace is restarted. We read the fault code, verify the cause with measurements and explain the repair.
Mora Home Services handles no-heat calls across upper Montgomery County through the winter. These calls can involve ignition, flame sensing, pressure and venting, or airflow. Those are repairs. We explain when repair is the right answer and when replacement deserves consideration.
What This Covers
Reading the control board fault code and confirming it with actual readings instead of trusting the blink pattern alone
Ignition faults: hot surface igniters, spark ignition, gas valves that won't open
Flame sensor inspection, cleaning where appropriate, and flame-rectification testing
Pressure switch and inducer motor faults, including blocked or improperly pitched venting
Limit switch trips investigated for airflow, overheating, control and switch faults
Blower motor, capacitor, and control board diagnosis
Heat exchanger inspection, and an honest conversation if we find a crack
Thermostat and low voltage wiring faults that present as a dead furnace
Combustion and venting safety checks before we leave the house
Signs Your Furnace Needs Attention
The furnace tries to light several times then stops and locks out
The blower runs but the air coming out is cool
It heats for a few minutes, shuts off, then starts again shortly after
A rumble, a boom, or a delay before it lights
The furnace runs but rooms that used to get warm no longer do
A flashing fault light visible through the sight window in the lower door
Any smell of gas: leave immediately and call 911 and your gas utility from a safe location
How We Handle a No-Heat Call
Safety comes before diagnosis
We begin with equipment safety checks. A suspected gas leak or combustion hazard takes priority over the repair conversation and requires the appropriate emergency response.
We read the fault, then verify it
The board stores a code. That code is a starting point, not an answer. A pressure switch code can be a bad switch, a blocked vent, a cracked hose, or a failing inducer, and only readings tell you which.
We explain it in plain language
You hear what failed and why it failed, because the why usually matters more. A limit switch that tripped because of a clogged filter will trip again if nobody mentions the filter.
We repair, then we watch it run
After the repair we run a full heating cycle and confirm it lights, holds, and shuts down the way it should. We check the venting and combustion again before we leave.
Repair or Replacement?
Decide from the equipment findings
Finding
What We Discuss
A serviceable fault in otherwise sound equipment
The repair, parts requirements and expected result.
A major component failure
Repair options, any applicable manufacturer coverage and replacement options.
Repeated faults or poor comfort
The cause, equipment condition and whether replacement would address it.
For a furnace fault, we explain the safety findings and whether the equipment can be repaired.
Common Furnace Problems We See
The problems that bring most of our heating and cooling calls, in the words people use when they call. Each one starts with a paid diagnostic visit and a written price before any repair.
Furnace will not turn on Check the thermostat is on Heat, the furnace switch and breaker are on, and the filter is not loaded. If it still does nothing, or it tries to light and shuts down, leave it off and book a diagnostic visit.
Furnace keeps turning on and off Short cycling usually points to a loaded filter, a limit switch trip, a flame sensor fault or an oversized unit. We test the operating sequence and explain the findings and any further testing needed.
Furnace blowing cold air The blower may be running without a heat call, or ignition, limit or airflow has stopped the burners. We check the operating sequence to find the cause in your system.
Furnace smells like burning If you see smoke or flames, leave the house and call 911 from outside. If you smell gas, do not operate switches or use a phone indoors; leave and call your gas utility and 911 from outside. A brief dusty odor can occur at the first heating use of the season. A persistent burning or electrical odor needs service; stop using the furnace and follow its shutdown instructions if safe to do so.
Furnace makes a loud bang or boom when it lights A bang or boom at ignition can indicate delayed ignition. Stop using the furnace, follow its shutdown instructions if safe, and arrange service before restarting it. If you smell gas, leave without operating switches and call from outside.
We provide furnace repair in Germantown, Clarksburg, Boyds, Montgomery Village, Gaithersburg, Derwood, Darnestown, North Potomac, Rockville, Olney, Washington Grove, Travilah and Redland.
A flame-sensing fault is one possibility, along with ignition, gas supply and control problems. We check the sequence and flame signal against the equipment instructions before recommending cleaning or replacement.
The fan may be running without a heat call, or an ignition, limit, airflow or control fault may have stopped the burners. We check the operating sequence to identify the cause in your system.
A lockout can be the control responding to a safety condition. Do not bypass a safety or keep resetting a persistent fault. Leave the furnace off and arrange a diagnostic visit. If you smell gas, leave immediately and call 911 and your gas utility from a safe location.
Yes. Heating and cooling service runs 8 AM to 7 PM, every day. Book a paid diagnostic visit online or call the office. We explain the finding and provide a written price before repair.
A furnace that sat all summer can fail to start for several reasons: the thermostat is still set to cool, the furnace switch or breaker is off, the filter is loaded, a condensate line is blocked, or the ignition or flame sensor has failed. Check the thermostat setting, the switch and the filter first. If it still will not start, or it tries to light and shuts down, leave it off and book a diagnostic visit.
A brief dusty odor at the first heating use of the season can occur as dust burns off. A persistent burning or electrical odor, or any smoke, is not normal. If you see smoke or flames, leave the house and call 911 from outside. If you smell gas, do not operate switches or use a phone indoors; leave and call your gas utility and 911 from outside. For a persistent odor with no smoke or gas, stop using the furnace and follow its shutdown instructions if safe to do so, then arrange a diagnostic visit.
Tell us what is happening and attach photos if they help explain it. Our office follows up to understand the work. Sending a request does not book a visit. Use the booking link above or call the office to arrange one.
1
Diagnose first.Understand the problem before recommending work.
2
Write the price.Know the scope before you approve it.
3
Do the agreed work.You approve. We do the work.
10 YearsIn business
20 YearsTrade experience
5,900+Jobs completed
Written price before work begins. Our office may call to clarify your request and explain the next step.