6 720 680 174 (2014/05)
Therm 8000S
44 | Problem solving
No flame ionization detected
with water flow.
1. Verify that all manual gas shut off valves are open.
2. Check gas type.
3. Check gas pressure.
4. Reset error code and open a water tap to cycle the heater in an effort
to purge air. Cycling hot water tap on and off multiple times may be
necessary. If heater still faults with EA error code, have a licensed gas
technician properly purge air out of the gas line leading to the water
heater.
5. Check three wire connections on the lower front of the heat
exchanger are secure.
6. Check venting specifications are met. Improper venting may cause
premature failure of the flame sensor rod.
7. Check that the minimum power fan speed has been adjusted to the
proper value. See chapter 8.6.
8. Observe inside the viewing window of the heat exchanger when a hot
water tap is opened. Sparking should be followed by a steady blue
flame. If flame is unstable/yellow with proper gas pressure, confirm CO2
readings.
Ionization failure during
operation.
1. Check gas type.
2. Check gas pressure.
3. Check three wire connections to ignition group on the lower front of
the heat exchanger are secure.
4. Verify that venting specifications are met. Improper venting may
cause premature failure of the flame sensor rod.
5. Check that the minimum power fan speed has been adjusted to the
proper value. See chapter 8.6.
6. Check and adjust CO2 readings.
Ionization error at standby.
1. Loose connection to the flame ionization rod. Verify that the thinner
wire leading from the control unit is securely connected to the set of
electrodes located on the lower front of the heat exchanger.
2. Flame ionization rod or control unit may be damaged. Call the
Technical Assistance.
Gas leakage error, gas valve
circuit not closing properly.
1. Disconnect power supply cord and check wire connections on gas
valve and the two connectors on the control board.
2. Flow water out of a hot water tap above the minimum activation point
(1.9 l/m). Measure voltage at the gas valve wire plug connection. The
voltage should measure 24VDC between the left pair of wires and
24VDC between the right pair of wires when the unit is operating. If
voltage is not proper, call the Technical Assistance.
3. Gas valve may be defective, call the Technical Assistance.
Display
Cause
Solution
Table 25
* By installer or service technician only.
