Operation - Hitachi YUTAMPO Series Service Manual

6 Troubleshooting
Indoor unit

6.2.1 Operation

Condition
Unit is not operating
The water does not become hot or it takes
a time for it to heat up
The water tank does not exceed 55 °C but
is set to a higher temperature.
Water comes out of the outdoor unit
Water comes out of the tank unit
Steam is coming out of the outdoor unit
No hot water
Water is coming out of the safety pressure-
relief valve (field-supplied)
The timer cannot be set
(*) In case of activation of the safety thermostat the heater is deactivated. It is necessary to push the thermostat reset
switch -1- after the temperature cools down.
71 SMGB0135 rev.0 - 06/2020
Check whether a power outage has occurred, a fuse is blown or the breaker has tripped.
Check whether the timer has been set and if it has been correctly set.
Check whether the water temperature is correctly set.
Check whether the air outlet of the outdoor unit has been blocked.
Check whether the unit is leaking water.
Check that the heater has power.
Push the safety thermostat reset switch and check that the heater has power. (*)
The outdoor unit discharges water during defrosting. In a cold area, this water could
freeze so the water outlet on the outdoor unit must not be blocked.
When the outdoor unit is installed overhead, use a bush to connect a drain pipe to the
water outlet to arrange proper discharge.
When the temperature of in coming water is very low and the atmosphere around the
tank is very humid, dew may form on surface of the metal or piping and may drop.
This is steam generated by frost melting during defrosting in the outdoor unit.
Check if a water outage has occurred. Turn the breaker off and close the water heater
and water valve during a water outage.
During heating operation, water leaking is normal.
The water in the tank is expanding from being heated and about 3% of tank capacity is
discharged.
Check whether the unit has been set to off-peak power supply.
The timer will not work when the unit is set to off-peak power supply.
Check the following
1
6