Troubleshooting

Aztec Classic Boiler

Red LED permanently illuminated indicates:

  1. High Limit Thermostat Tripped due to:
  • Faulty system circulation pump,
  • System isolation valve closed,
  • Air in water system,
  • High limit thermostat out of calibration,
  • Temperature adjustment on PCB incorrect, or
  • Lack of water in system.

2.  Faulty thermistor or thermistor wire connection,
3. Main inlet wiring incorrectly wired,
4. Voltage drop less that 207V, or
5. Faulty or damaged PCB.

Red LED flashes indicates:
1. Poor electrical connection to the elements and the PCB controller,
2. Element Failure,
3. Element Cable damage or loose, or
4. PCB Running Temperature overheating.

Green LED but boiler not working, indicates:
1. Link wire on call terminal block missing

No LEDs Illuminated but boiler working, indicates:
1. Blown fuse located on PCB above transformer

Residual Current Device Trips indicates:
1. RCD incorrectly sized,
2. Main terminal block is short circuiting, or
3. Faulty element.

Aztec Gold Boiler

Red LED permanently illuminated indicates:
1. High Limit Thermostat Tripped due to:

  • Faulty system circulation pump,
  • System isolation valve closed,
  • Air in water system,
  • High limit thermostat out of calibration,
  • Temperature adjustment on PCB incorrect, or
  • Lack of water in system.

2. Faulty thermistor or thermistor wire connection,
3. Main inlet wiring incorrectly wired,
4. Voltage drop less that 207V, or
5. Faulty or damaged PCB.

1st Red LED flashes indicates:
1. Poor electrical connection to the elements and the PCB controller,
2. Element Failure,
3. Element Cable damage or loose, or
4. PCB Running Temperature overheating.


2nd Red LED flashes indicates:
1. Low water pressure less than 1 Bar due to:

  • Faulty wiring to pressure safety switch,
  • Faulty gauge,
  • Lack of water in system, or
  • leaks in system.

Green LED but boiler not working, indicates:
1. Link wire on call terminal block missing


No LEDs Illuminated but boiler working, indicates:

1. Blown fuse located on PCB above transformer

Residual Current Device Trips indicates:
1. RCD incorrectly sizes,
2. Main terminal block is short circuiting, or
3. Faulty element.