Overheat limit open.
- High temperature limit switch is open (set temperature 210°F).
- Check CH, DHW and GEN pump operation.
- Assure adequate flow through the boiler by checking supply & return temperatures in the status menu. The difference should be less than 40°F (22°C).
- Compare temperature readings on the supply sensor against the temperature gauge. If the gauge is significantly higher check the sensor and replace if necessary.
