12
Detecting and rectifying faults
e
Danger!
Risk of death from electric shock!
Live lines and connections may cause a
potentially lethal electric shock.
> Do not attempt to repair the unit yourself
under any circumstances.
> Do not remove the cover under any circum-
stances.
> If the unit ever malfunctions, inform an
approved heating engineer immediately.
> In the event of a fault, unplug the mains plug.
> In the event of a leak, shut off the cold water supply
to the electric domestic hot water cylinder immedi-
ately.
> Employ an approved heating engineer to rectify the
fault.
> Do not tamper with the inner workings of the unit
under any circumstances.
In the event of a fault, the safety temperature limiter
(STL) will cut out automatically.
> Always have the cause of the fault determined and
rectified by an approved heating engineer before you
attempt to restart the unit.
> If the unit has not yet been filled with water, fill the
unit first as described under section 5 "Start-up".
> To reset the STL, unplug the mains plug briefly.
Temperature controller defective
The Vaillant electric domestic hot water cylinder is
equipped with a resettable safety temperature limiter
(STL).
In the event of a temperature controller defect, the
safety temperature limiter prevents damage caused by
overheating.
If the temperature controller is defective or if the elec-
tric domestic hot water cylinder is otherwise damaged:
> Unplug the mains plug.
> Ensure that the power cannot be restored inadvert-
ently to any of the supply lines and connections.
> Open the electric domestic hot water cylinder.
> Determine and rectify the cause of the fault
> If necessary, replace the temperature controller
and/or safety temperature limiter.
> Close the casing on the electric domestic
hot water cylinder.
> Plug the mains plug back in.
Operating instructions for electric domestic hot water cylinders VEN 5/6 U and O (plus) 0020129648_01
Detecting and rectifying faults 12
12.1
Replacement parts
An overview of the available genuine Vaillant replace-
ment parts can be obtained:
– from your wholesaler (replacement parts catalogue,
printed or on CD-ROM)
– in the Vaillant Expert PartnerNET (replacement parts
service) at http://www.vaillant.com/.
The mains connection line must be exchanged only for
a Vaillant connection line, see applicable replacement
parts catalogue.
INT
21
EN