Download Meridian 5.24 Installation manual

⇒ adjust by turning the screw only 1/8 turn and waiting for at least 1 minute after every
turn for the value to stabilise;
⇒ Proceed as follows to check the setting at minimum capacity:
⇒ switch the heating potentiometer to minimum; the boiler is now operating at
minimum power
⇒ Adjust the fan rpm to the minimum power using trimmer P2 on the boiler PCB. The
rpm are displayed on the front display as shown above when adjusting the fan
speed at maximum power.
⇒ if necessary turn the off-set screw (A) of the gas valve clockwise to increase the
percentage of CO2, or anti-clockwise to decrease it;
♦ Check the percentage of CO2 by operating the boiler at maximum capacity (heating
potentiometer turned to maximum) and then at minimum again (heating potentiometer
turned to minimum)
♦ Repeat the adjustment procedure, if necessary;
♦ Seal the gas flow rate adjustment devices;
♦ Put the back of the control panel and the front cover back into position; turn the
selector to OFF to deactivate the “Chimney sweep” mode and then switch on the
boiler again
3.5 Boiler diagnostic
The boiler display informs the After-Sales Service personnel in case of malfunctioning
or lockout. The table of the lockout codes and the correspondent meanings is shown at
the paragraph 1.3 of the "Instructions for use".
3.6 Maintenance function
The chimney sweep function is active when puts functioning selector on the
relative position (the last in clockwise, see fig. 1), and contemporaneously is
active the relative indication on the display.
This function makes the boiler operate at the maximum heating power for 15 minutes. This
resets all controls; only the safety thermostat and the limit thermostat are still working: the
regulation board is set on low or high temperature. Keeping the boiler in stand-by, turn the
selector on the DHW position and press the reset switch for 10 seconds; this will activate
the function which is displayed by the simultaneous blinking of both the DHW and CH
LEDS; the technician is so enabled to check the combustion parameters. Once the checkups are finished, turn the boiler off and then on in order to deactivate the maintenance
function.
Warning: before activating the maintenance function, make sure that the radiator valves or
zone valves are open.
3.7 Adjustment of nominal heating power.
If the heating power needs to be adjusted, do the following.
To make these adjustments, you must follow this procedure:
a)
move:
i. the sanitary knob to half way,
ii. the thermo knob to minimum
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