Outdoor Units - Marstair WM Technical Manual

7. Setting the ON Time
Press the TIMER ON set 'S' button and step to the required ON time. Hold the button down for repeated stepping. Press the TIMER
ON 'C' button to cancel the ON time.
8. Setting the OFF Time
Press the TIMER OFF 'S' button and step to the required OFF time. Hold the button down for repeated stepping. Press the TIMER OFF
'C' button to cancel the OFF time.
9. Only ON Time Selected
Unit will turn ON at the selected time and stay ON.
10. Only OFF Time Selected
Unit will turn OFF at the selected time and stay OFF.
H ON/STANDBY button when time programmes are selected
11. Use of the Pink
At any time, pressing the Pink button will either start the unit or return it to standby mode. The unit will remain at this
condition unless an appropriate ON or OFF time has been programmed.
12. Cold Start
In Cool or Heat mode, not Auto, after more than 3 days without power, or after 2 hours of non-operation, the set
temperature is automatically raised (in heating mode) or lowered (in cooling mode) by 2°C until this temperature is
reached or the unit has run for 20 minutes after which the unit operates with the displayed temperature. This decreases
the time taken to reach set point.
13.Fan Speed ( heat pump systems only)
In heat pump systems, the indoor fan always starts at low speed in heating mode, and changes to the selected speed when the indoor
coil is warm, returning to low speed when not calling for heating.
14. Off cycle delay
To prevent operational problems, cooling restart is delayed for 3 minutes following power up, or from the time the unit was last cooling
or heating, (if heat pump). Cooling or heating, (if heat pump) will operate for a minimum of 2 - 3 minutes.
15. Displays
Heat Fan
F 4
Amber Red
OFF OFF
OFF ON
BLINKS ON
ON ON
ON ON
OFF ON
OFF ON
BLINKS OFF
Diagnostics
OFF BLINKS x 4
OFF BLINKS x 4
OFF BLINKS x 4
OFF BLINKS x 1
16. Heat Pump Only
If the outdoor coil temperature reaches 68°C, the compressor and outdoor fan will stop until the coil cools to 50°C.
17. Commands Refused
a. Attempts to set temperatures outside the display range are not transmitted.
b. If heating commands are refused, the installer's programming is incorrect - call the engineer.
18. Battery Replacement
It is advisable to replace the batteries as soon as the display begins to fade. Correct transmission cannot be guaranteed if the battery
is failing.
19. Power Cuts
The unit permanently memorises its settings.
20. User Maintenance
Isolate the unit at the mains supply before commencing any maintenance work.
The unit should always be used with a filter. In order to maintain efficiency it is important that the filter behind the air intake grille is
cleaned regularly:
! Remove the filter(s) from behind the air intake grille.
! Wash the filter (in tepid water only) and shake dry before use.
! Alternatively tap the filter gently to remove dust or vacuum clean.
! To clean the unit use soap or a non-scratch liquid cleaner.
Dry Cool
I D
DIAGNOSTICS
Red Green
No power, manual OFF, timed OFF,
OFF OFF condensate high level, fault in condensate
control
OFF ON Cooling mode selected
OFF ON AUTO - predominantly cooling
OFF OFF Heating mode selected
OFF BLINKS AUTO - predominantly heating
OFF OFF Fan mode selected
ON OFF Dry mode selected
OFF OFF Outdoor unit defrosting
OFF OFF Room sensor missing
OFF OFF Indoor coil sensor missing
BLINKS OFF Heat pump only, outdoor coil sensor missing
OFF BLINKS Compressor overload
–N–N–F–F–F–N–N–
2 x 1.5V AAA
batteries
-49-