How to Test and Replace a Relay in Commercial Kitchen Equipment

Commercial kitchen equipment relays are unsung heroes waiting quietly behind the scenes, ensuring that everything from ovens to refrigeration units operates safely and efficiently. In the bustling environment of a commercial kitchen, every moment of downtime can lead to significant losses, both in food quality and revenue. Relays control the power flow to heating elements, motors, and compressors, acting as crucial switches that either activate or shut down these components as needed.

Understanding how to properly test and replace commercial kitchen equipment relays is essential for chefs, restaurant owners, and maintenance professionals ready to keep things running smoothly. In this guide, you'll learn what relays are, how to spot signs of failure, the correct procedures for testing and replacement, and tips to choose the right part for your equipment.

What is a Relay in Commercial Kitchen Equipment?

A relay is an electrically operated switch designed to open and close circuits electromechanically or electronically. In commercial kitchen equipment relays, these switches enable control over high-power components, such as heating elements in ovens, compressors in refrigerators, and solenoids in dishwashers, using safer, lower-voltage signals.

You'll find commercial kitchen equipment relays in nearly every major appliance, including:

Ovens and combi-ovens (to switch heating elements, fans, and lights)
Deep fryers (to control the power to the heating coils)
Refrigeration units (regulating compressors, defrost cycles, and fans)
Dishwashers (managing pump motors and heating elements)

Relays act as the nerve center of these appliances, seamlessly flipping electrical loads on and off based on signals from thermostats, control boards, or timers.

Signs of a Faulty Relay in Commercial Kitchen Equipment

A malfunctioning relay can lead to a variety of operational headaches. Knowing the main symptoms of faulty commercial kitchen equipment relays helps you catch issues early, minimizing downtime and costly repairs. Key warning signs include:

Equipment not turning on or off: If ovens, fryers, or refrigerators suddenly stop responding to controls, a failed relay may be to blame.
Intermittent power issues: Equipment that works sporadically often suffers from a relay with failing contacts or coil.
Clicking sounds without startup: Relays typically produce a clicking noise as they actuate. If you hear clicks but nothing powers up, the contacts inside the relay may be worn or stuck.
Burnt smell or visible damage: Overheated relay coils or contacts can produce a burnt odor, and severe cases may show charring or cracked casings.

Whenever any of these symptoms appear in your appliances, check the commercial kitchen equipment relays as a top suspect.

Safety Precautions Before Testing or Replacing a Relay

Safety must always come first when working on commercial kitchen equipment relays. Electrical shock, burns, and equipment damage are real risks. Always take these precautions:

Disconnect the power supply: Switch off and unplug the appliance before investigation or repair.
Use insulated tools: Only handle relays with tools that have non-conductive handles. Wearing insulated gloves adds extra safety.
Follow manufacturer guidelines: Each brand and model may have specific safety and disassembly instructions. Consult your equipment's manual or the manufacturer's online resources.

How to Test a Commercial Kitchen Equipment Relay?

Testing commercial kitchen equipment relays involves using a multimeter to check for proper function.

Identify and access the relay

Refer to the appliance's schematic or user guide to locate the relay.
Remove covers or panels as necessary to expose the relay without damaging wiring or other components.

Identify relay terminals

Most relays have four or five terminals:

Two for the coil (to energize and actuate the switch)
Two or three for the contacts (Common, Normally Open, Normally Closed). Check the relay's label or the schematic for correct identification.

Continuity and coil resistance test

Set your multimeter to the 'Ohms' setting.

Place the multimeter probes on the coil terminals. Compare the reading to the relay's specs; a very high reading or 'OL' (open loop) typically means a broken coil.
With no power to the coil, test between the common and Normally Closed (NC) terminals for continuity. It should read zero ohms or close to it.
Briefly power the coil using a suitable voltage source. Now, check continuity between Common and Normally Open (NO); you should see continuity, indicating the relay is switching correctly.

Interpret results

If any readings are out of specification (e.g., infinite resistance or no continuity when expected), the relay is likely faulty and should be replaced.

How to Replace a Commercial Kitchen Equipment Relay

Replacing commercial kitchen equipment relays isn't complicated, but attention to detail is critical:

Locating the relay: Identify the faulty relay and take note of how it's mounted (screwed in or on a socket).
Removing the faulty relay: Mark the location of each terminal or take a photo. Gently disconnect wires or pull the relay out of its socket.
Installing the new relay: Match the new relay to the old one by voltage, current, and pin configuration. Insert the new relay carefully, ensuring a snug fit. Reattach wires exactly as they were.
Reconnecting and testing the equipment: Reassemble any covers or enclosures you removed. Test the equipment to ensure normal operation. All functions relying on the relay should now work correctly.

Tips for Choosing the Right Replacement Relay

Selecting the correct commercial kitchen equipment ensures safe operation and long-term reliability.

Match voltage and amperage ratings: Using a relay with lower ratings than required can result in overheating or failure.
Buy from certified parts distributors: Counterfeit or low-quality relays are risky and may invalidate warranties.
Use manufacturer-approved parts: Many brands specify or recommend exact relays for their equipment. Substandard substitutes can cause malfunctions or void warranties.
Check for third-party certifications: Look for UL, CE, or other safety certifications to ensure global compliance.

Understanding and maintaining your commercial kitchen equipment reliability is key to kitchen uptime and food safety. Recognize the signs of relay failure early, such as equipment not starting, intermittent issues, or burnt smells. Always use proper safety precautions and follow a step-by-step approach to testing and replacing relays. Choosing the right replacement part from a credible distributor ensures smooth, uninterrupted operation. Promptly addressing relay issues in your appliances will drastically reduce costly downtime, helping your commercial kitchen run efficiently. PartsFe UK is your one-stop shop for commercial equipment replacement parts for your catering needs in the UK. We offer a wide range of parts from top-selling brands.