Service Menu - Mitsubishi Electric EHST20 Series Operation Manual

4
Customising Settings for your Home
<explanation of legionella Prevention mode operation>
• At the time entered by the installer 'Start time' useful heat from the system is
diverted to heat the water in the storage tank.
• When the temperature of the stored water exceeds the 'Hot Water temp.' set
by the installer (above 65°C) water is no longer diverted to the tank.
• Whilst legionella prevention mode is in operation hot water is not directed to
the space heating circuit.
• Directly after LP mode operation 'Duration of max. temp' will operate. The du-
ration of this feature is set by the installer and during its operation stored water
temperature will be monitored.
• If stored water temperature should drop to LP restart temp, LP mode will re-
start and water flow from the plate heat exchanger will be directed to the tank
to boost the temperature. Once the set time for duration of max. temp has
passed LP mode will finish and not recur for the set interval (set by installer).
• It is the responsibility of the installer to ensure the settings for legionella pre-
vention are compliant with local and national guidelines.
important
Please note that LP mode uses electric heaters (if present) to supplement the en-
ergy input of the heat pump. Heating water for long periods of time is not efficient
and will increase running costs. The installer should give careful consideration
to the necessity of legionella prevention treatment whilst not wasting energy by
heating the stored water for excessive time periods. End-users should seek ad-
vice from their installers if they wish to change the LP mode settings.

Service Menu

The service menu is password protected to prevent accidental changes being
made to the operation settings, by unauthorised/unqualified persons.
Tank temp.
Stop
Stop temp.
Legionella
hot water temp.
Restart temp.
Space
Start
Heating
LP mode
Duration of Max. temp.
( LP mode : Legionella Prevention Mode )
Stop
Restart
Mode
LP mode
finish
Time
2