Message overview
(cont.)
Cause
Short circuit/lead break, secondary circuit flow tempera-
ture sensor upstream of the instantaneous heating wa-
ter heater
70 Room temp. sensor HC1
■
No frost protection mode via room temperature sen-
sor
No room temperature hook-up
■
No room temperature-dependent control
■
Cause
Short circuit, room temperature sensor, heating circuit
without mixer A1/HC1
71 Room temp. sensor HC2
No frost protection mode via room temperature sen-
■
sor
■
No room temperature hook-up
■
No room temperature-dependent control
Cause
Short circuit, room temperature sensor, heating circuit
with mixer M2/HC2
72 Room temp. sensor HC3
■
No frost protection mode via room temperature sen-
sor
■
No room temperature hook-up
■
No room temperature-dependent control
Cause
Short circuit, room temperature sensor, heating circuit
with mixer M3/HC3
73 Room temp. sensor SKK
No cooling mode
Cause
Short circuit, room temperature sensor, cooling circuit
Measure
Check resistance value (Pt500A) at connection X25.3/
X25.4: See "Controller and sensor PCB".
Measure
Check remote control. Replace remote control if re-
quired: See "Vitotrol" installation and service instruc-
tions.
Measure
Check remote control. Replace remote control if re-
quired: See "Vitotrol" installation and service instruc-
tions.
Measure
Check remote control. Replace remote control if re-
quired: See "Vitotrol" installation and service instruc-
tions.
Measure
Check resistance value (NTC 10 k
"Controller and sensor PCB") or on remote control unit.
Troubleshooting
) at plug F16 (see
Ω
87