Detecting And Rectifying Faults 8 - Vaillant VED Operating And Installation Instructions

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.
> Before replacing water-bearing components, you must
drain the unit completely. To do this, loosen the cold
and hot water connections.
i
When detecting and rectifying faults, always
follow the order stated in tab. 8.1 for each
individual point.
Fault/cause
No power.
Resistance is outside the
range of < 200 ohm.
Water flow not adequate,
water pressure is too low.
The safety switch has been
triggered.
Tab. 8.1 Possible faults and remedial action
Installation instructions for VED electric instantaneous water heater 0020149586_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

Detecting and rectifying faults 8

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.
Measure the resistance value between the connections 1 and 4 on the elec-
tronics.
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.
Carry out the checks as described in points 1 - 3 and start up the unit again.
If the safety switch is triggered again, the unit is defective. Inform Vaillant
customer service.
15