Raypak MVB 5042004 - Manual (Page 47)

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d. Gas is on at the meter and the heater.
e. Incoming dynamic gas pressure to the gas
valve is NOT less than 4.0 in. WC for natural
gas or propane gas.
To Turn Off Gas To Appliance
1. Shut off manual gas valve field installed near gas
inlet connection on back of heater.
2. Remove upper front panel.
3. Set the thermostat to lowest setting.
4. Turn off all electrical power to the appliance if serv-
ice is to be performed.
5. Replace access panel.
UDB Fault History
To view the fault codes in the UDB history file:
1. Press the UP or DOWN buttons on the membrane
switch for 2 seconds to access the fault history.
2. Press either button to scroll through the recorded
faults in history.
3. The most recent fault recorded will be the first fault
displayed (the last 16 faults are stored in the his-
tory, on a rolling basis). There is no time or date
stamp associated with these faults.
4. When the history of faults has been exhausted,
pushing the UP or DOWN buttons again will roll
the fault history over and it will start again.
5. To exit the fault history, wait for 10 seconds and
the board will automatically exit the history mode.
To clear the fault history, press and hold both the UP
and DOWN buttons for 5 seconds while the power is
on.
Diagnostic information is provided any time a fault is
recorded. This information is intended to assist in
locating the problem with the heater, but is not exhaus-
tive.
If multiple fault conditions occur at the same time, only
the fault that caused the heater to shut down will be
recorded in the history.
NOTE: Once the history has been cleared, it cannot
be recovered.