What is the cost to replace a furnace part?
For the Icp N8MPN050B12A1 80+ single-stage gas furnace, the cost to replace a part depends on which component failed and whether you’re paying for labor. Parts can range from under $50 (switches) to several hundred dollars (motors and gas valves), plus service charges.
Typical part price ranges for this model
Below are examples of common replacement parts we see for N8MPN050B12A1 and their typical parts-only price range.
| Part type (example) | What it does | Typical parts-only cost |
|---|---|---|
| Door switch | Proves the blower door is installed | $30 to $80 |
| Limit switch | Shuts burners off if overheating occurs | $20 to $80 |
| Igniter / flame sensor | Lights gas and proves flame | $150 to $500 |
| Blower motor | Moves heated air through ducts | $300 to $700 |
| Gas valve | Controls gas flow to burners | $400 to $900 |
What usually adds to the total cost
Even when the part price is known, the installed cost changes based on access, diagnostics, and setup.
- Diagnostic/service call fee (often applied toward repair)
- Labor time (simple switch vs. motor or gas valve)
- Electrical testing and wiring repairs if a short caused the failure
- Setup and safety checks after replacement (especially gas components)
- Warranty status and required documentation
Warranty and maintenance factors (important)
Icp warranty terms commonly require the furnace to be installed and operated per printed instructions and codes, and they may require yearly maintenance as a condition of coverage. Replacement parts are typically covered for the unused portion of the original warranty period. For heat exchangers on N8MPN series furnaces, coverage is commonly listed as 20 years for defects from the original installation date (residential applications). See the owner's manual for the exact terms that apply to your installation.
Parts on this model that commonly drive cost
If you are budgeting, these are the parts on N8MPN050B12A1 that most often create a higher parts total.
- Gas valve SV9641M4510 (higher-cost, safety-critical)
- Furnace blower fan motor 1014028 (higher-cost, more labor)
- Igniter 1149856 (mid to higher-cost, common no-heat cause)
Why it matters
Pricing the repair correctly helps avoid repeat failures. For example, a failed igniter can be the root cause, but a dirty flame sensor, weak ground, or airflow problem that trips the limit switch can cause repeated shutdowns and extra service calls.
Last updated: February 2026
What are the most common furnace repairs?
The most common repairs on an Icp N8MPN050B12A1 80+ single-stage gas furnace involve airflow restrictions (dirty filter), ignition and flame-sensing problems, and blower or safety-switch issues. Many “no heat” calls trace back to basic maintenance, while gas valve and venting problems typically require professional service.
Most common repairs we see (and what you notice)
- Air filter replacement/cleaning: weak airflow, short cycling, overheating; dirty filters are a leading cause of poor heating performance.
- Ignition or flame-sensing service: furnace tries to start then shuts off, or won’t light.
- Blower motor or capacitor issues: humming, slow start, intermittent blower, poor airflow.
- Limit switch trips: burners shut off, blower may keep running; often linked to restricted airflow.
- Door switch problems: furnace appears dead when the panel is not seated correctly.
- Venting/combustion air checks: soot smell, condensation, or performance issues; vent connector should be clear, sloped upward, and sound.
Parts that commonly get replaced on this model
If troubleshooting points to a failed component, these are common replacement categories for the N8MPN050B12A1:
| Symptom | Likely area | Example part for this model |
|---|---|---|
| No ignition or unreliable lighting | Ignition/flame sensing | Furnace pilot igniter and sensor 1009524 |
| Blower won’t start or runs poorly | Blower drive components | Capacitor 12908 |
| Burners shut off from overheating | Safety temperature control | Furnace temperature limit switch 1013102 |
| Furnace won’t run with door on | Safety interlock | Furnace door switch 1171981 |
Quick checks we recommend before replacing parts
Follow the safety and inspection guidance in the N8MPN050B12A1 owner's manual.
- Turn off electrical power before removing panels or doing maintenance.
- Inspect the air filter monthly; clean or replace as needed.
- Confirm the furnace door is fully seated (door switch must close).
- Look for obvious venting issues: blockage, corrosion, loose connections.
- If flames look abnormal, stop and have a qualified service agency inspect.
Why it matters
Furnace repairs often start as airflow or ignition problems; fixing those early helps prevent repeated limit trips, nuisance shutdowns, and unnecessary wear on the blower motor and controls.
Last updated: February 2026
What is the most expensive part to fix on a furnace?
On an Icp N8MPN050B12A1 80+ single-stage gas furnace, the most expensive repair is typically a major component replacement, especially the heat exchanger (high labor and safety-critical work). Other high-cost repairs often include the blower motor and the gas valve.
Typical “most expensive” furnace repairs (what we see most often)
- Heat exchanger: usually the highest total cost because it is labor-intensive and tied to safe combustion and venting.
- Blower motor: can be expensive due to the motor cost plus setup and airflow verification.
- Gas valve: higher part cost and requires careful setup and leak checks.
- Control board (if equipped): can be costly and may require diagnostic time.
- Inducer/venting components: costs add up when venting or pressure-sensing issues are involved.
Quick cost comparison (typical ranges)
| Repair item | Why it gets expensive | Typical total repair range (parts + labor) |
|---|---|---|
| Heat exchanger | Major disassembly, combustion safety checks | $1,000 to $3,000+ |
| Blower motor | High part cost, airflow setup | $400 to $2,000+ |
| Gas valve | Precision gas control, leak testing | $300 to $1,200+ |
| Control board | Diagnostics, electrical troubleshooting | $300 to $1,500+ |
Model-specific notes for N8MPN050B12A1
Your manual includes important safety guidance for gas furnaces and emphasizes following warnings and using qualified service for installation, adjustment, and maintenance. For safe shutdown and restart steps (including waiting 5 minutes to clear gas), use the N8MPN050B12A1 owner's manual.
If you are pricing a repair related to ignition or flame sensing, these parts are commonly involved:
Why it matters
The “most expensive part” is usually the one that combines (1) a high-cost component with (2) the most labor and (3) required safety verification. On gas furnaces, that combination most often points to the heat exchanger and gas-train or airflow components.
Last updated: February 2026
What is the most common part to fail on a furnace?
On the Icp N8MPN050B12A1 furnace, the most common “failure” we see is actually airflow restriction from a dirty air filter, which can overheat the furnace and trip safety shutoffs. After that, ignition-related parts (igniter and flame sensing) and safety switches are frequent culprits.
Most common causes (in order)
- Dirty or clogged air filter: most common cause of inadequate heating and can lead to overheating shutdowns.
- Flame sensing or ignition problems: dirty sensor, weak ignition, or intermittent lighting.
- Overheat protection trips: a temperature limit switch can open if airflow is low or the furnace runs too hot.
- Draft/venting issues: blocked venting or combustion air problems can prevent safe operation.
- Loose wiring or failed electrical components: especially after vibration or service work.
Quick checks we recommend before replacing parts
Turn off power to the furnace before opening panels.
- Replace the air filter and confirm return vents are open and unobstructed.
- Make sure the furnace area is clear and openings and ducts are not blocked.
- If the furnace overheats, shut off the gas valve before shutting off electrical power.
- Inspect visible wiring for damage or loose connections.
- If ignition is inconsistent, plan to inspect ignition and flame-sensing components.
Common “failure points” and what they do
| Symptom | Likely area | What it affects |
|---|---|---|
| Runs briefly, then shuts off | Airflow or limit protection | Prevents overheating damage |
| No heat, no ignition | Ignition system | Starts burner flame |
| Blower runs, but no heat | Gas/ignition safety chain | Allows gas and ignition sequence |
| Shuts down with venting concerns | Venting/combustion air | Safe exhaust and combustion |
Parts that are often involved on this model
If troubleshooting points to a component, these are common replacements for the N8MPN050B12A1:
- Igniter 1149856 (ignition source)
- Furnace pilot igniter and sensor 1009524 (ignition and flame sensing)
- Furnace temperature limit switch 1013102 (overheat safety)
- Furnace door switch 1171981 (proves the door/panel is in place)
Why it matters
A furnace usually shuts down because a safety circuit detects unsafe conditions (overheating, poor combustion air, or ignition problems). Fixing the root cause (often airflow) prevents repeat shutdowns and protects major components.
For model-specific safety and maintenance intervals, follow the N8MPN050B12A1 owner’s manual.
Last updated: February 2026





