Maintenance And Repair; Periodic Inspection; Temperature And Pressure Relief Valve; (Ptr Valve) - Bosch Compress 3000 DW FOO Installation Instructions Manual

38 | Maintenance and repair

6 Maintenance and repair
WARNING:
The water heater should be serviced by a
qualified professional and in accordance
with the Plumbing Standard AS/NZS
3500.4 and local authority requirements.
WARNING:
Before manually operating the relief valve,
make certain no one will be exposed to the
danger of coming in contact with the hot
water released by the valve. The water may
be hot enough to create a scald hazard. The
water should be released into a suitable
drain to prevent injury or property damage.
It is part of normal operation for the
Temperature and Pressure Relief valve to
discharge periodically. This is due to thermal
expansion in a closed water system. If this
discharge becomes excessive and runs
continuously, contact plumbing contractor.
Do not plug the relief valve outlet.
Properly maintained, your water heater will provide years of
dependable trouble-free and economic service.
It is suggested that a routine preventive maintenance program
is established and strictly followed by the user.
6.1

Periodic Inspection

It is recommended that a periodic inspection of the operating
controls, heating elements and wiring should be made by
service personnel qualified in electric appliance repair.
Most electrical appliances, even when new, make some sound
when in operation. If the hissing or singing sound level
increases excessively, the electric heating element may require
cleaning. Contact a qualified installer or service agent.
Additionally it is also recommended that the evaporator and
refrigeration circuit are checked every two years for dust and
residues. In dusty environments it may be necessary to have
the appliance checked and cleaned on a more regular basis.
6.2 Temperature and pressure relief valve (PTR
Valve)
At least every 6 months:
6 720 808 869 (2014/06)
▶ Lift and release the lever handle on the temperature and
pressure-relief valve, to make certain the valve operates
freely.
Allow several liters to flush through the discharge line to an
open drain.
Never replace the PTR Valve with one which has a higher
pressure rating than is specified for your water heater.
If the valve does not discharge water when the release lever is
opened or does not seal properly when release lever is closed,
replacement by an authorised person must be arranged
without delay.
The PTR Valve is not serviceable.
DANGER:
Before manually operating the relief valve,
make certain no one will be exposed to the
hot water released by the valve. The water
drained from the tank may be hot enough to
present a scald hazard and should be
directed to a suitable drain to prevent injury
or damage.
6.3

Flushing tank

A water heater's tank can act as a settling basin for solids
suspended in the water. It is therefore not uncommon for hard
water deposits to accumulate in the bottom of the tank.
It is advisable to periodically flush the tank of these deposits by
draining and then refilling the unit (see section 6.4).
6.4

Draining the Water Heater

CAUTION:
Shut off power to the water heater before
draining water.
CAUTION: Risk of scalding!
Check the appliance's DHW temperature
before opening the safety valve.
▶ Wait until the water temperature has
dropped enough to prevent burns and
other damage.
Large volumes of water will drain from the
cold water inlet (>270 liters).
▶ Ensure proper drainage of water.
Compress 3000 DW FOO