C Fault Codes; D Troubleshooting - Vaillant ecoTEC plus Operating Instructions Manual

Status code
S.23 DHW mode: Ignition
S.24 DHW mode: Burner on
S.25 DHW mode: Pump/fan overrun
S.26 DHW mode: Fan overrun
S.27 DHW mode: Pump overrun
S.28 Domestic hot water burner anti-cycling time
S.30 Room thermostat (RT) is blocking heating mode
S.31 Summer mode active or eBUS controller is blocking heating mode
S.34 Frost protection active
S.85 Service message "Insufficient water flow rate, product in standby mode for 10
minutes"

C Fault codes

Message
F.22 System pressure
too low
F.28 Ignition unsuc-
cessful

D Troubleshooting

Fault
Product does not The gas stopcock installed on-site
start up: and/or the gas stopcock on the product
is closed.
– No domestic
The power supply in the building is dis-
hot water
connected.
– Heating does
not heat up
The product is switched off.
0020261390_01 ecoTEC plus Operating instructions
Other displays
Possible cause
The system pressure
is too low. Water de-
ficiency in the heating
installation.
After five unsuccessful
ignition attempts, the
product has switched
to fault mode.
Cause
Meaning
Measure
▶
Fill the heating installation.
1. Check whether the gas stopcock is open.
2. Check whether the siphon is free.
3. Check whether the flue is free.
4. Press and hold the reset button for one
second.
– Reset attempts: ≤ 5
5. If you have been unable to eliminate the
ignition fault after the reset attempt, consult
a competent person.
Open both gas stopcocks.
Check the fuse in the build-
ing. The product automatically
switches on after the power
supply is restored.
Switch on the product (→ "Switch-
ing on the product" section).
Appendix
Measure
19