RV Air Conditioner Replacement Parts Kit | 3314998.000 Safety Limit Switch & Grille

RV Air Conditioner Replacement Parts Kit – 3314998.000 Safety Limit Switch & Grille

The safety limit switch (high-limit thermostat) is a critical safety component in your RV air conditioner that prevents the evaporator coil from overheating or freezing. When the coil temperature exceeds safe limits, the switch opens to shut down the compressor, protecting your AC unit from damage. A faulty limit switch can cause your AC to shut down prematurely, not cool at all, or potentially damage the compressor.

This RV air conditioner replacement parts kit includes the safety limit switch (replaces Dometic 3314998.000), mounting hardware, and replacement grille. It’s designed as a direct fit for Dometic and Duo Therm RV air conditioners, making repair quick and easy.

Compatibility

• Dometic Brisk Air II (B57915, B59516, B59186)
• Dometic Penguin II (640315, 640316, 641815, 641816)
• Dometic Duo Therm (57915, 59516, 59186, 600315)
• Dometic Air Conditioners with 3314998.000 limit switch
• Most 13,500 BTU and 15,000 BTU Dometic rooftop AC units
• Replaces part numbers: 3314998.000, 3314998.005, 3109492.003

Kit Contents

• Safety Limit Switch (high-limit thermostat) — replaces 3314998.000
• Replacement Grille — air discharge grille with adjustable louvers
• Mounting Hardware — screws and clips for installation
• Installation Instructions — step-by-step guide

Specifications

Installation Guide

1. Safety first: Turn off 120V AC power at the circuit breaker. Turn off the generator if running. Allow the AC unit to cool completely.
2. Access the unit: From inside the RV, remove the air conditioner ceiling assembly (inner shroud) by removing the 4 mounting screws. Lower the assembly carefully — it may still be connected to wiring.
3. Disconnect wiring: Unplug the wiring harness connectors from the ceiling assembly. Set the assembly aside.
4. Locate the limit switch: The safety limit switch is typically mounted on the evaporator coil housing, near the front of the unit. It has two wires connected to it.
5. Remove old switch: Disconnect the two wires from the switch terminals. Remove the mounting screw holding the switch to the coil housing.
6. Install new switch: Mount the new limit switch in the same position. Reconnect the two wires (polarity does not matter for this bi-metal switch).
7. Replace grille: If replacing the grille, remove the old grille from the ceiling assembly by releasing the mounting clips. Install the new grille by snapping it into place.
8. Reassemble: Reconnect the wiring harness to the ceiling assembly. Lift the assembly into position and secure with the 4 mounting screws.
9. Test operation: Restore 120V AC power. Turn on the air conditioner. Verify the compressor starts, the fan runs, and cool air is discharged. Let the unit run for at least 15 minutes to ensure proper operation and that the limit switch doesn’t trip prematurely.

Common Symptoms of a Bad Limit Switch

• AC compressor runs for a few minutes then shuts off (premature trip)
• AC doesn’t cool — compressor won’t start (switch stuck open)
• AC runs continuously without cycling (switch stuck closed — dangerous!)
• Evaporator coil freezes up (ice buildup on the coil)
• Warm air blowing from vents despite AC being on
• AC unit makes unusual clicking sounds
• Circuit breaker trips when AC is running

Frequently Asked Questions

Q: How do I test if my limit switch is bad?

A: With power off, disconnect the wires from the limit switch. Use a multimeter set to continuity (ohms) mode. Touch the probes to the two switch terminals. A good switch at room temperature should show continuity (0 ohms or a beep). If there’s no continuity, the switch is stuck open and needs replacement. You can also test by heating the switch with a hair dryer — it should open (lose continuity) at around 140°F and close again as it cools.

Q: Can I bypass the limit switch temporarily?

A: We strongly recommend NOT bypassing the safety limit switch. This switch is a critical safety component that prevents the evaporator coil from overheating, which can cause compressor damage, refrigerant leaks, or even fire. If the switch is tripping frequently, there’s an underlying problem (low refrigerant, dirty coil, restricted airflow) that needs to be addressed. Bypassing the switch can lead to catastrophic AC failure.

Q: Why does my limit switch keep tripping?

A: Frequent limit switch tripping usually indicates an underlying issue: (1) Dirty or clogged air filter restricting airflow, (2) Dirty evaporator coil reducing heat transfer, (3) Low refrigerant charge, (4) Faulty compressor or capacitor, (5) Restricted ductwork or closed vents. Check and clean the filter and coil first. If the problem persists, have a qualified RV technician check the refrigerant charge and compressor.

Q: Is this kit compatible with my specific AC model?

A: This kit is compatible with most Dometic and Duo Therm 13,500 BTU and 15,000 BTU rooftop air conditioners that use the 3314998.000 limit switch. If you’re unsure, check your AC model number and compare it to our compatibility list, or contact our technical team with your model number for confirmation.

Related Products

• Dometic 3311924 Relay Board — Replacement relay board for Duo Therm analog RV AC
• Coleman Mach 15 AC Controller — Replacement controller for Coleman Mach air conditioners
• 12V 13500BTU Parking AC — Complete rooftop AC heat pump for RVs

Need help repairing your RV air conditioner? Contact our technical team with your AC model number and symptoms. Free shipping and duties included on all orders.