What MFD capacitor do I need for my Carrier AC?

The correct replacement for Carrier model MH1AJX018010AAAA is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Carrier equipment which lists the model number MH1AJX018010AAAA.

My AC hums but will not start. What part do I need?

An AC that hums but will not start is the classic symptom of a failed capacitor. The capacitor provides the electrical boost needed to start the compressor and fan motors. When it fails, you hear the hum of the motor trying to start but it cannot overcome inertia. Other symptoms include the fan spinning slowly, the AC cycling on and off rapidly, or a visibly swollen or leaking capacitor. Replacement cost: $15 to $80 for the part, DIY in 30 minutes.

Is this capacitor compatible with Bryant or Payne systems too?

Many Carrier parts are cross-compatible with Bryant and Payne systems since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across multiple brand labels with different model numbers. To verify cross-compatibility, check your Bryant or Payne equipment service manual for cross-compatible part numbers, or contact info@nationalhvacparts.com with your model number for confirmation.

Carrier

OEM Carrier Single Run Capacitor P291-0303 for MH1AJX018010AAAA

Name: OEM Carrier Single Run Capacitor P291-0303 for MH1AJX018010AAAA
Brand: Carrier
SKU: CARRIE-MH1AJX018010AAAA-CAPACITOR-P291-0303
Price: 17.00 USD
Availability: InStock

SKU: CARRIE-MH1AJX018010AAAA-CAPACITOR-P291-0303 Brand: Carrier

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OEM Carrier Single Run Capacitor P291-0303 / P291-0304 for Model MH1AJX018010AAAA

This OEM single run capacitor is the factory-specified replacement for the Carrier MH1AJX018010AAAA air handler or mini-split system. A single run capacitor provides the continuous electrical charge required to keep the blower or fan motor running at correct speed and efficiency. When this capacitor degrades or fails, you'll notice symptoms such as a humming motor that won't spin up, intermittent shutdowns, sluggish blower performance, or complete motor failure — often causing the system to trip on thermal overload. Replacing this part promptly protects the motor from costly burnout damage.

Specs: Single run capacitor | Factory-matched MFD rating | 370V or 440V rated (verify on unit data plate) | Round or oval case | OEM part numbers P291-0303 and P291-0304 — confirm your unit's label before ordering
OEM vs Generic: This is a genuine Carrier OEM capacitor manufactured to exact factory MFD tolerance (±3%). Aftermarket alternatives frequently carry ±10% tolerance, placing excess stress on motor windings and reducing overall system lifespan.
Install Difficulty: 2/5 — Always disconnect power at the breaker and discharge the capacitor fully before handling. Tools needed: flathead and Phillips screwdrivers, 1/4" nut driver, needle-nose pliers, and a multimeter to verify discharge. Photograph all wiring connections before removal.
Warranty & Shipping: Backed by a 1-year OEM factory warranty against defects. In stock and ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed as a direct OEM replacement for the Carrier MH1AJX018010AAAA. This listing covers both OEM part numbers P291-0303 and P291-0304 — both are single run capacitors for this model. Always verify the MFD rating and voltage on your unit's data plate or existing capacitor before placing your order. Our parts specialists are available to confirm fitment before you buy — don't guess on a safety-critical electrical component.

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $75
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

OEM Carrier Single Run Capacitor...

$17.00

Frequently Asked Questions

Does this Capacitor fit my Carrier MH1AJX018010AAAA?

Yes. This is the factory-specified OEM capacitor for the Carrier MH1AJX018010AAAA. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the capacitor on my Carrier MH1AJX018010AAAA?

Difficulty: Easy (20–30 min)
Step 1: Turn off power at breaker. Step 2: Open condensing unit panel. Step 3: Photograph the old capacitor wiring (Common/Herm/Fan). Step 4: Discharge old capacitor with insulated screwdriver. Step 5: Disconnect and remove old capacitor. Step 6: Mount new capacitor, reconnect wires to matching terminals. Step 7: Close panel, restore power, test. Tools: screwdriver, needle-nose pliers.

My AC hums but won’t start. What part do I need?

An AC that hums but won’t start is the classic symptom of a failed capacitor. The capacitor provides the electrical boost to start the compressor. When it fails, you hear humming but the motor can’t overcome inertia. Other symptoms: fan spinning slowly, AC cycling on/off rapidly, or a visibly swollen capacitor. Fix: replace capacitor ($15–$80 DIY, 30 min).

Is this capacitor compatible with Bryant or Payne too?

Many Carrier parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my Carrier capacitor?

OEM strongly recommended. OEM capacitors have ±6% MFD tolerance vs aftermarket ±10%. The looser tolerance causes motor winding stress, higher temps, and shorter compressor life. Price difference is only $10–$20 — OEM is the clear value choice.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

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OEM Carrier Single Run Capacitor P291-0303 for MH1AJX018010AAAA

OEM Carrier Single Run Capacitor P291-0303 / P291-0304 for Model MH1AJX018010AAAA

Shipping Information

Return Policy

Frequently Asked Questions