E15
Pennco Polarity / Line Voltage Fault

Boiler shows E15 and will not start, often after wiring changes

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Incorrect line/hot-neutral wiring, Shared neutral with other circuits, Loose ground connection, Voltage outside acceptable range

How to Fix / Troubleshooting

Danger: This involves 120V or 240V line voltage. If you are not qualified, contact an electrician or boiler technician.

  • Verify power source: Confirm the boiler is on a dedicated circuit with correct breaker size per Pennco installation manual.
  • Check polarity: Using a multimeter or outlet tester, verify that hot, neutral, and ground are correctly wired at the service switch and boiler junction box.
  • Inspect ground: Ensure the boiler chassis is properly grounded to the electrical system ground.
  • Measure voltage: Confirm supply voltage is within the specified range (typically 108–132 VAC for 120V systems).
  • If E15 persists: The control board may have been damaged by incorrect wiring and require replacement.
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Repair Difficulty

Professional Required 5/5

Required Part

Boiler Integrated Control Board
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