Operating instructions

32
For users and contractors
6. Troubleshooting by the user
Fault Cause Remedy
The heating system inside the
instantaneous water heater will not
start in spite of the tap being fully
open.
No voltage. User / contractor:
Check the fuses in your fuse board.
The start-up volume required to start
the heater has not been reached.
Contamination or scaling of perlators in
water taps or shower heads.
User / contractor:
Clean and / or descale.
Table 5
7. Troubleshooting by the contractor
Fault Cause Remedy
Stage II in the appliance will not
start.
Pressure in the cold water line too low. Descale and if required replace shower
head / perlator.
Contamination.
Clean sieve (
H
22).
Throughput volume controller
(
A
7, output switch unit) will not
start in spite of tap being fully
opened.
The start-up volume required to start the
heater has not been reached.
Clean sieve (
H
22).
No hot water in spite of audible
sound of the differential pressure
switch starting.
Safety pressure limiter (AP 3) has
switched the appliance off for safety
reasons.
Remove cause of fault (e.g. faulty
pressure washer).
Open downstream tap for 1 minute.
This depressurises and cools down the
heating system, protecting it against
overheating.
Press the pushbutton on the safety
pressure limiter (push
A
8).
No voltage. Check fuse / MCB (fuse box).
Heating system faulty. Test the heating system resistor and
replace if required.
Table 6