A.O. Smith DRE 52 Installation, User And Service Manual page 52

Indication
A safety device is
activated
EN
50
Cause
The main safety thermostat (G1) is
activated
The row safety thermostat (G2) is
activated.
The thermal fuse broke the control
circuit.
Measure
- Make sure the water heater is
completely filled.
- Tap off water, so the temperature
drops in the water heater.
- Make sure all connections are
connected correctly (refer to the wiring
diagram (see A.5)).
- Use the white button to manually reset
the thermostat.
- If necessary, replace the safety
thermostat (G1).
- Tap off water, so the temperature
drops in the water heater.
- Make sure all connections are
connected properly (refer to the wiring
diagram (see A.5)).
- Use the red button to manually reset
the thermostat.
- If necessary, replace the safety
thermostat (G2).
- Check what caused the excessive heat
rise of the element area.
- Measure the resistance value over the
thermal fuse. The value needs to be
<5 Ohm.
- If necessary, replace the thermal fuse
wiring.
Installation, Maintenance and Service part