Hitachi YUTAMPO Serie Installations- Und Betriebshandbuch Seite 30

MAINTENANCE
Regular inspection and maintenance of the hot
water tank
Inspection of installation status
- Check for water leaks from pipe joints.
- Check the electrical insulation.
- Check the piping insulation.
Functional inspection
Check the pressure-relief valve for water leaks.
-
- Check the electric heater.
- Check the pressure reducing valves and auto purge valve
of the water installation.
Cleaning and maintenance
- Remove the scale sediments from the heat exchanger
and the bottom of the tank.
11.5 WHEN THE UNIT WILL NOT BE USED FOR AN EXTENDED PERIOD
When the unit will not be used for a month or more
- Turn the circuit breaker off.
- Drain the water inside the tank. Follow the instructions in
the section "Preparing for operation" when using the tank
again at a later point.
When the unit will not be used for a short period of less than a
month
- Turn the circuit breaker off.
- Close the water valve. Refill the tank when using the tank
again at a later point.
24 PMML0451 rev.2 - 03/2018
Replacement of parts
- Pressure reducing valves of the water installation,
pressure relief valves and auto purge valves wear out
quickly. The quality of the water used may make it
necessary to replace those often. Replace all parts which
should be replaced according to the results of inspections.
Consideration of the specifications of the pressure reducing
valves for water works and the pressure relief valves
- The tank has to be mounted with a pressure relief valve
of 3/4" diameter, following standard NF36,40. (This is
applicable for France, but local regulations may also apply
in other states). The pressure relief must be operated
regularly in order to remove the scale deposit and to
check whether it is clogged.
In heavy snowfall regions
When the outdoor unit is installed in a heavy snowfall region, the
necessary actions must be take to prevent the air inlets or outlets
from becoming blocked by snow, as it may lead to a drop of
heating capacity, and eventually to breakdown of the unit.
Draining procedure
- Turn the circuit breaker off.
- Close all the mixer taps.
- Open the hot water knobs of all the connected mixer taps.
- Open the drain valve (Once the draining starts, it may
take 20 to 30 minutes until completion).
- Close the drain and hot water knobs of all the connected
mixer taps.