HVAC Motor or Compressor Not Starting? Dual Run Capacitor 36-20-153744 — Restores 20/15MFD Motor Run Capacitance
If your HVAC system hums but won’t start, or a motor circuit is running weakly, a failed dual run capacitor is one of the most common causes. The dual run capacitor combines two run-capacitor sections in one case, supporting two motor circuits simultaneously. When it fails, one or both circuits lose the electrical support needed to start and run efficiently. ⚡ Used in applications requiring separate 20MFD and 15MFD run capacitance from a single oval body. Part 36-20-153744 is the Rotom OEM replacement that restores proper run capacitance to compatible 20/15MFD motor circuits.
🇺🇸 Matching U.S. Part Number: 36-20-153744
📦 Special Order This Part — Ships in 3–5 business days. Tracking sent once your order ships.
❓ Is This the Right Part?
This is the correct fix if ALL of the following are true:
- ✔ Motor circuit requires exactly 20/15MFD dual run capacitance (not 20/5MFD, 20/10MFD or any other value)
- ✔ Electrical supply to the unit is confirmed OK
- ✔ Motor or compressor windings are not open or shorted
- ✔ ONLY problem is the motor or compressor failing to start or running below rated speed
Not sure? Send us your model number — we’ll confirm before you order.
🔧 Common Symptoms
- Motor or compressor hums but won’t start
- One or both motor circuits run at reduced speed or efficiency
- Unit short-cycles or trips thermal overload
- Capacitor is visibly bulged, leaking, or measures out of spec
✔ If these symptoms match, this is the most likely failed component in the motor circuit.
📦 Part Details
- Part Number: 36-20-153744
- Type: Dual motor-run capacitor (two sections in one oval case)
- Capacitance: 20/15 µF
- Voltage: 370/440 VAC
- Shape: Oval
- Width: 2.80 in
- Depth: 1.77 in
- Height: 3.55 in
- Features: Built-in pressure interrupter; UL and cUL recognized
- Brand/OEM: Rotom / AllTemp
- Availability: Special Order — Ships in 3–5 business days
- Direct Oval Equivalents: POCFD2015, POCFD2015A, TOCFD2015, CD20+15X440, 12083
Inspect the contactor and motor windings at the same time. A capacitor that has failed due to age or heat stress often indicates the motor itself is approaching end of life. Confirming motor condition during the same service call prevents a repeat failure.
⚙️ Installation
Skill Level: Moderate — 30 to 60 minutes. Disconnect and lock out power to the unit before opening the electrical compartment. Capacitors retain a hazardous charge after power is removed — discharge safely before handling. Match the terminal connections exactly to the original wiring. Confirm oval mounting strap fit, terminal layout and cabinet clearance before installing — dimensions vary between equivalent brands. Diagnosis and replacement should be completed by a qualified HVAC technician.
✓ Compatible Models
Compatibility for this capacitor is specification-based. Both capacitance values must remain exactly 20/15MFD, and the replacement voltage must equal or exceed the original equipment requirement. Confirm the oval shape and dimensions (2.80” × 1.77” × 3.55”) fit the mounting strap and cabinet clearance before ordering. Contact us to verify your model number before ordering.
💡 Pro Tip
The 20/15MFD combination is less common than 20/5MFD or 20/10MFD. Both values must match exactly. Note that 12164 (MARS) is a 370V-only capacitor and is not a valid replacement where 440V is required — despite appearing alongside this part in some AllTemp cross-reference listings. Always read the label on the original capacitor and confirm the voltage rating before ordering.
✅Compatibility & Cross Reference
Not sure about your model number? Call 1-877-899-7278 and we’ll help you confirm. All brand names are the property of their respective owners and are used for compatibility reference only.
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