Installation and Operating Guide

Problem solving
Greentherm T9900 SE/i – 6 720 813 635 (2022/01)
72
F3 Electronic control unit internal error. ▶ Reset error (touch and hold on/off button for 3
seconds).
If appliance’s configuration is required:
▶ See section 6.6 to configure appliance (region,
power, type and gas type) and perform an automatic
combustion adjustment according to the
section 8.12.
1)
If the problem persists:
▶ Replace electronic control unit.
1)
F7 Electronic control unit internal error. ▶ Reset error (touch and hold on/off button for 3
seconds).
If the problem persists:
▶ Replace electronic control unit.
1)
F8 Electronic control unit internal error. ▶ Reset error (touch and hold on/off button for 3
seconds).
If the problem persists:
▶ Replace electronic control unit.
1)
F9 Gas valve driver internal fault. ▶ Check gas valve wire connections.
1)
If the problem persists:
▶ Replace the wire connections and/or electronic
control unit.
1)
FA Gas leakage in the gas path (gas valve or gas
manifold shut-off valves).
▶ Replace the gas valve and/or gas manifold.
1)
▶ After gas valve and/or gas manifold replacement
perform gas and air tuning ( section 8.12).
1)
FC Touch screen key pressed for more than 20
seconds.
▶ Release the touch screen key.
▶ Clean the touch screen display.
Display reads
SOLAR but without
existence of solar
thermal system.
Display reads
SOLAR and water
temperature low.
Power demand lower than appliance minimum
output power.
▶ Increase hot water flow.
▶ increase setpoint temperature.
Display shows a red
X.
HMI (display) is not communicating with Electronic
Control Unit.
▶ Reset the appliance by unplugging it for some
seconds (at least 10) and plug it back in.
▶ Replace the HMI (display) and/or wire connections
and/or electronic control unit.
High pitch noise
(whistling)
Combustion flame with gas in excess or lack of air. ▶ Check if gas type is correct ( section 6.8).
1)
▶ Check gas inlet pressure ( section 4.13).
1)
▶ Perform gas and air tuning ( section 8.12).
1)
Low pitch noise
with vibration
(rumbling)
Combustion flame with air in excess or lack of gas. ▶ Check if gas type is correct ( section 6.8).
1)
▶ Check gas inlet pressure ( section 4.13).
1)
▶ Perform gas and air tuning ( section 8.12).
1)
1) only to be carried out by qualified contractors.
2) see temperature resistance charts in fig. 68 and 69.
3) Error reset also possible by shutting-off water flow to the unit, and turning it back on.
Display Description Solution