Are you struggling to reduce your electric water heater bills or looking to install a timer for better energy efficiency? You’re not alone—thousands of US homeowners search for reliable solutions to control their water heating schedules. Understanding Master Plumber Electric Water Heater Time Control 318352 Wiring is essential for safe installation and optimal performance. This comprehensive guide will walk you through everything you need to know, from basic wiring principles to advanced troubleshooting techniques.
What Is the Master Plumber 318352 Time Control?
The Master Plumber 318352 is a mechanical timer switch specifically designed for electric water heaters. This device allows you to program specific on/off cycles, helping you save significantly on electricity costs by preventing unnecessary heating during off-peak hours.
Key Features and Specifications
Before diving into the wiring process, it’s crucial to understand what makes this timer unique:
- Voltage Rating: 240V AC (standard for US electric water heaters)
- Amperage Capacity: Typically rated for 30-40 amps
- Timer Mechanism: Mechanical dial with tripper pins for setting on/off times
- Compatibility: Works with most standard residential electric water heaters
- Safety Certification: UL-listed for residential use
According to the U.S. Department of Energy, water heating accounts for approximately 18% of home energy use. Installing a timer like the 318352 can reduce these costs by 10-20% annually, making it a worthwhile investment for budget-conscious homeowners.
Safety Precautions Before Starting
Warning: Working with electrical components requires proper knowledge and caution. If you’re uncomfortable with electrical work, hire a licensed electrician.
Essential Safety Steps
- Turn Off Power: Locate your main electrical panel and switch off the circuit breaker supplying power to your water heater. Verify the power is off using a non-contact voltage tester.
- Verify No Voltage: Double-check that no electricity is flowing to the water heater terminals before touching any wires.
- Use Proper Tools: Ensure you have insulated screwdrivers, wire strippers, and appropriate gauge wire connectors.
- Follow Local Codes: Check your local building codes and NEC (National Electrical Code) requirements. Some jurisdictions require permits for electrical modifications.
- Wear Protective Gear: Use safety glasses and insulated gloves throughout the installation process.
For more information about electrical safety standards, visit Wikipedia’s article on electrical safety.
Tools and Materials Needed
Gather these items before beginning your installation:
Required Tools
- Non-contact voltage tester
- Wire strippers (capable of handling 10-12 AWG wire)
- Phillips and flathead screwdrivers
- Needle-nose pliers
- Electrical tape
Required Materials
- Master Plumber 318352 timer unit
- Appropriate gauge electrical wire (typically 10 AWG for 30-amp circuits)
- Wire nuts or push-in connectors
- Mounting screws (usually included with timer)
- Conduit or cable clamps (if required by local code)
Step-by-Step Wiring Instructions
Step 1: Access the Water Heater Electrical Panel
Remove the access panel on your electric water heater. This is typically located on the side of the tank and secured with screws. Once removed, you’ll see the thermostat(s) and heating element connections.
Step 2: Identify Existing Wiring
Most electric water heaters have two heating elements (upper and lower), each controlled by a thermostat. The wiring configuration usually includes:
- Line wires (L1 and L2): Two hot wires bringing 240V power
- Load wires: Wires connecting to the heating elements
- Ground wire: Bare copper or green-insulated wire
Note: Take a photo of the existing wiring before disconnecting anything for reference.
Step 3: Disconnect Power Wires
Carefully disconnect the line wires (L1 and L2) from the upper thermostat. These are the wires that bring power into the water heater. Label them clearly if needed.
Step 4: Connect Timer Input Terminals
The Master Plumber 318352 has input terminals labeled “LINE” or “IN”:
- Connect the L1 line wire to one input terminal on the timer
- Connect the L2 line wire to the other input terminal
- Tighten all connections securely but avoid over-tightening
Step 5: Connect Timer Output Terminals
The output terminals are labeled “LOAD” or “OUT”:
- Run new wires from the timer’s output terminals to the upper thermostat’s line terminals
- Connect one output wire to where L1 was previously connected on the thermostat
- Connect the second output wire to where L2 was previously connected
- Ensure all connections are tight and secure
Step 6: Ground Connection
Connect the ground wire properly:
- Attach the ground wire to the timer’s grounding terminal (if equipped)
- Ensure the water heater’s grounding system remains intact
- Verify continuity with a multimeter if available
Step 7: Set Timer Trippers
The mechanical timer uses small plastic or metal pins called “trippers”:
- ON trippers: Place these at times when you want the heater to operate
- OFF trippers: Place these at times when you want the heater off
Example Schedule for Maximum Savings:
- ON: 5:00 AM (for morning showers)
- OFF: 8:00 AM
- ON: 5:00 PM (for evening use)
- OFF: 10:00 PM
This schedule avoids heating water during overnight hours and midday when demand is typically low.
Step 8: Test the Installation
- Replace the access panel temporarily
- Turn the circuit breaker back on
- Rotate the timer dial to verify it moves smoothly
- Check that the timer clicks on and off at the programmed times
- Verify the water heater receives power during ON periods
Step 9: Final Inspection
- Ensure all wires are properly secured and not pinched
- Verify no exposed wire ends are visible
- Confirm the timer is mounted securely
- Check that the access panel fits properly
Common Wiring Mistakes to Avoid
| Mistake | Consequence | Solution |
|---|---|---|
| Reversing line and load wires | Timer won’t function properly | Double-check labels before connecting |
| Loose connections | Overheating and fire hazard | Tighten all terminals securely |
| Incorrect wire gauge | Voltage drop and overheating | Use minimum 10 AWG for 30A circuits |
| Skipping ground connection | Safety hazard and code violation | Always connect ground wire properly |
| Not verifying power is off | Electrocution risk | Always test with voltage tester first |
Troubleshooting Common Issues
Timer Doesn’t Click On/Off
Possible Causes:
- Timer mechanism is jammed
- Tripper pins are not properly seated
- Motor inside timer has failed
Solutions:
- Manually rotate the dial to check for smooth movement
- Remove and reinstall tripper pins
- If motor is faulty, replace the entire timer unit
Water Heater Not Receiving Power During ON Times
Check These Items:
- Verify circuit breaker is on
- Test voltage at timer input terminals (should read 240V)
- Check output terminals for voltage during ON period
- Inspect all wire connections for tightness
Timer Runs Continuously
Potential Issues:
- Tripper pins may be missing or damaged
- Internal contacts may be welded shut
- Timer may be set to “manual on” position
Resolution:
- Install proper ON/OFF trippers
- Replace timer if contacts are damaged
- Ensure timer is in automatic mode
Benefits of Using a Water Heater Timer
Installing the Master Plumber 318352 offers several advantages:
Energy Savings
- Reduces standby heat loss by 10-20%
- Prevents heating during unused hours
- Lower monthly electricity bills
Extended Equipment Life
- Reduces cycling frequency
- Minimizes mineral buildup
- Decreases wear on heating elements
Environmental Impact
- Lower carbon footprint
- Reduced energy consumption
- Contribution to sustainability goals
When to Call a Professional
While many homeowners can successfully install this timer, consider hiring a licensed electrician if:
- You’re unfamiliar with electrical systems
- Your local code requires professional installation
- You encounter unexpected wiring configurations
- The water heater is older or has unusual connections
- You’re uncomfortable working with 240V circuits
Professional installation typically costs $100-$200 but ensures code compliance and safety.
Frequently Asked Questions
Q1: Can I install the Master Plumber 318352 on a gas water heater?
A: No, the 318352 is designed specifically for electric water heaters operating on 240V. Gas water heaters use different control systems and don’t require this type of electrical timer. Attempting to install it on a gas unit would be ineffective and potentially dangerous.
Q2: How much money can I save with a water heater timer?
A: Most homeowners save between $30-$75 annually on electricity costs, depending on usage patterns, electricity rates, and timer settings. In regions with higher electricity costs (like California or New York), savings can exceed $100 per year. The timer typically pays for itself within 1-2 years.
Q3: Will using a timer void my water heater warranty?
A: Generally, no. Installing an external timer doesn’t modify the water heater itself. However, check your specific manufacturer’s warranty terms. Most warranties remain valid as long as the installation doesn’t cause damage to the unit. Keep documentation of professional installation if applicable.
Q4: Can I set different schedules for weekdays and weekends?
A: The Master Plumber 318352 is a mechanical timer with a 24-hour cycle, so it repeats the same schedule daily. For different weekday/weekend schedules, you’d need a digital programmable timer or smart controller. Alternatively, manually adjust the trippers when your schedule changes.
Q5: What happens if the power goes out?
A: Mechanical timers like the 318352 don’t rely on internal batteries or memory. When power returns, the timer resumes operation based on its current dial position. You may need to reset the time if the outage was extended, but your tripper settings remain intact.
Q6: Is the 318352 compatible with tankless water heaters?
A: No, tankless (on-demand) water heaters operate differently and don’t benefit from timer controls. They only heat water when there’s demand, so adding a timer would interfere with their normal operation. The 318352 is designed exclusively for traditional storage-tank electric water heaters.
Conclusion
Mastering the Master Plumber Electric Water Heater Time Control 318352 Wiring process empowers you to take control of your energy costs while maintaining comfort and convenience. By following this comprehensive guide, you can safely install your timer, optimize your heating schedule, and enjoy significant savings on your electricity bills.
Remember, proper installation is crucial for both safety and performance. Take your time, follow each step carefully, and don’t hesitate to consult a professional if you encounter difficulties. The investment in time and effort will pay dividends through reduced energy costs and extended equipment life.
Ready to start saving? Share this guide with friends and family who might benefit from installing a water heater timer. Follow us on social media for more DIY home improvement tips and energy-saving strategies. Together, we can make our homes more efficient and environmentally friendly!
Have questions or experiences to share? Leave a comment below—we’d love to hear about your installation journey!
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