ICP NUGK100DH03 gas furnace Parts

Restricted airflow from a dirty air filter is the most common cause of a gas furnace shutdown, but the most commonly replaced parts are usually ignition and airflow components. On an Icp gas furnace model NUGK100DH03, frequent failures involve the blower system (motor, wheel, capacitor) or a safety switch that stops heat when conditions are unsafe.

• Clogged air filter causing overheating and a safety shutdown
• Blower problems: weak airflow, squealing, or no air movement
• Ignition/sensing issues: furnace tries to light, then shuts off
• Safety switch trips (door switch, pressure-type switch, rollout-type safety)
• Electrical issues: loose wiring, blown fuse, tripped breaker

If your furnace runs but airflow is weak or the blower will not start, these are the first parts we check on this model’s parts list:

• Capacitor 12907 (run capacitor for a motor circuit)
• Furnace blower fan motor 613209 (moves heated air through the ductwork)
• Furnace blower fan wheel 600587 (the wheel that actually pushes air)
• Switch 611872 (a safety or control switch that can prevent operation)

A furnace is designed to shut down when it cannot move enough air or when a safety circuit detects a problem. Fixing the root cause (often airflow) prevents repeat shutdowns and protects major components like the heat exchanger.

Last updated: February 2026

For an Icp gas furnace like model NUGK100DH03, the most expensive repair is typically a heat exchanger replacement because it is labor-intensive and tied to safe combustion. Among common serviceable parts, a blower motor or inducer (draft) motor assembly is often the priciest.

These are the repairs that usually drive the highest total cost (part plus labor):

• Heat exchanger: often the highest-cost repair due to disassembly and safety checks
• Inducer (draft) motor assembly: high part cost; affects venting and ignition
• Blower motor: high part cost; affects airflow and comfort
• Control board (if equipped): can be expensive and requires careful diagnosis
• Gas valve: moderate-to-high cost; must be set up and tested correctly

On this model’s parts list, the highest-priced items are major motors. If you are comparing “most expensive part” strictly by part price, these are the usual top contenders:

We recommend confirming the failure first; many “bad motor” symptoms are caused by simpler issues.

• Turn off power to the furnace before inspecting wiring or components
• Check the air filter and supply/return vents for restrictions (overheating can mimic motor problems)
• Inspect wiring connections for looseness, heat damage, or corrosion
• If the blower will not start, test the run capacitor (a common, lower-cost failure)
• If the inducer will not run, verify the pressure switch and venting are not blocked

Helpful DIY skill for diagnosis: how to use a multimeter to test electrical parts video

The “most expensive part” is not always the right part to replace first. Accurate diagnosis prevents repeat breakdowns, protects comfort and safety, and avoids spending on a motor or assembly when the real issue is a capacitor, switch, or wiring problem.

Last updated: February 2026

The most common repairs on an Icp gas furnace like model NUGK100DH03 involve airflow problems (dirty filter or blower issues), ignition or flame-sensing problems, and electrical control failures. Many “no heat” calls trace back to a few serviceable parts and basic checks.

• Dirty air filter or blocked return vents: weak airflow, overheating shutdowns, short cycling.
• Flame sensor cleaning or replacement: furnace ignites then shuts off within seconds.
• Ignition problems (hot surface igniter or pilot system, depending on design): no flame, repeated tries.
• Blower motor or capacitor failure: no air movement, humming, intermittent starts.
• Inducer/vent motor issues: pressure switch errors, won’t start, loud draft motor.
• Control or relay problems: blower runs at the wrong time, won’t energize heat call.

1. Set thermostat to Heat and raise the setpoint 3 to 5 degrees.
2. Replace the furnace filter and open all supply registers.
3. Check the furnace door switch is fully engaged and the access panel is seated.
4. Verify the circuit breaker is on; if it trips again, stop and investigate wiring.
5. If the blower will not start, test the run capacitor with a meter.

For safe electrical testing basics, use our guide how to use a multimeter to test electrical parts video.

Catching airflow, ignition, and control issues early prevents nuisance shutdowns, reduces strain on the blower and heat system, and helps avoid repeated limit trips that can shorten component life.

Last updated: February 2026

An Icp gas furnace like model NUGK100DH03 is built around a heat-making section (burners and heat exchanger) and an air-moving section (blower and controls). Common service parts include motors, capacitors, switches, relays, and burner components.

• Burner assembly: mixes gas and air and lights to create heat
• Heat exchanger: transfers heat to the air without mixing combustion gases into your airflow
• Inducer (draft) motor: pulls combustion air in and pushes exhaust out through the vent
• Blower (circulating) motor and wheel: moves heated air through ductwork
• Ignition system: ignitor and flame-sensing components that prove safe ignition
• Controls and safeties: relays, switches, and sensors that manage operation and shut the furnace down if unsafe

These are examples of real replacement parts commonly tied to airflow and control issues:

Knowing the major furnace parts helps you troubleshoot symptoms faster. For example, weak airflow often points to the blower motor, blower wheel, or a failing capacitor, while no-heat problems can involve burner and safety controls.

• Turn off electrical power at the furnace switch or breaker
• Shut off the gas supply valve if you are opening the burner compartment
• Let the furnace cool before touching internal components
• Take a photo of wiring connections before removing any electrical part

Last updated: February 2026