Replacement Parts And Accessories 7; Detecting And Rectifying Faults 8 - Vaillant electronicVED plus Operating And Installation Instructions

7 Replacement parts and accessories
The original components of the unit were also certified
as part of the CE declaration of conformity. If you do not
use certified Vaillant genuine spare parts, this voids the
CE conformity of the unit. We therefore strongly recom-
mend that you fit Vaillant genuine spare parts.
You can find information about available Vaillant genu-
ine spare parts from the contact address provided on
the reverse of this document.
> If you require spare parts for servicing or repair work,
use only Vaillant genuine spare parts.
Fault/cause
No power.
Resistance is outside the
range of < 200 ohm.
Water flow not adequate,
water pressure is too low.
Nothing shown on the dis-
play, no function can identi-
fied. The safety switch has
been triggered.
No hot water or fluctuation in
the outlet temperature.
Flow rate cannot be set or
the outlet temperature is not
reached. Defective motorised
valve.
Tab. 8.1 Possible faults and remedial action
Installation instructions for the electronicVED plus electric instantaneous water heater 0020149585_00
Procedure
1. Check the electrical con-
nections
2. Check the electrical func-
tion of the heating ele-
ment
3. Check the minimum water
flow rate
4. Check the safety switch
5. Check the electronics
6. Check the motorised valve The unit is ready for operation, the display electronics are connected, the

Replacement parts and accessories 7

Detecting and rectifying faults 8

8 Detecting and rectifying faults
The faults listed here must only be rectified by an
approved heating specialist company. When rectifying
faults, note the following:
> Only use genuine spare parts for repairs.
> Make sure the parts are correctly fitted and that their
original position and alignment are retained.
> When removing water-carrying parts, capture the
residual water (up to 0.4 litres) left inside the unit
using a suitable container.
i
When diagnosing and rectifying faults, always
follow the order stated in tab. 8.1 for each
individual point.
Testing/rectifying
Ensure that the unit is supplied with the L1, L2 and L3 mains voltage.
Check the protective devices.
De-energise the unit and open the unit cladding.
Check all the connection line connectors.
Undo the connections 1 and 4 from the electronics. Measure the resistance
value between the connections 1 and 4 on the electronics.
The resistance must be < 200 ohm.
Ensure that there is an adequate water flow rate of more than 3 l/min. If
the water volume is too low, check the water pressure, the fittings and the
filter in the inlet. If the required water volume is not reached, check the
motorised valve.
Carry out the checks as described in points 1 - 5. Once you have found the
fault, start the unit up again. If you have not found the fault, do not start
the unit up. Inform Vaillant customer service.
Slowly open a draw-off point near the unit until approx. 3 l/min. Check
whether a relay switch (a click) can be heard.
No switch (click) can be heard:
De-energise the unit and remove the unit cladding.· Check that the impeller
moves freely by blowing hard on the inlet side; if necessary, clean or
replace the impeller.· Otherwise, replace the electronics.
Switch (click) can be heard:
Check that the water temperature reaches the target temperature.
Fluctuation in the outlet temperature:·
Replace the electronics.
Water temperature is not reached:·
Check the motorised valve as described in point 6.· If the motorised valve
functions correctly, change the electronics.
unit cladding is closed. De-energise the unit for approx. 10 seconds. Switch
the mains voltage on again. A motor noise must immediately be audible
(the motorised valve is starting up). If you do not hear a motor noise, the
valve is defective and must be replaced.
If the motorised valve is working perfectly again, set the temperature to
60 °C. Quickly open a draw-off point with the highest flow rate possible
(e.g. a bath). Then slowly reduce the flow rate and measure whether the
selected outlet temperature is reached.
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