Sequence Of Operation - Rheem ThermaForce RTGH-L199i User's Information Manual

NOTE
The unit is equipped with a
Frost Protection feature. This
feature will operate the unit's
burner to help protect the unit
from freezing. If the unit is
in a hard lock-out condition
the burner will not operate.
We are not responsible for
damages to the unit, and/
or related components,
nor property damages that
may result from freezing
conditions.
USER'S INFORMATION MANUAL
TANKLESS WATER HEATER 199

SEQUENCE OF OPERATION

When the unit is powered up the controller enters a self-diagnostic mode, and
displays the controller software version in the main display .
The Sequence of Operation is as follows:
The unit receives a call from Domestic Hot Water heating from the internal
1 .
flow sensor.
The unit performs a safety check and energizes the fan for a pre-purge
2 .
(Service Display = 3) .
Once the 5-second pre-purge is compete, the unit enters a 5-second trial for
3 .
ignition (Service Display = 4) . If the unit fails to ignite, the unit will complete a
5-second inter-purge then another 5-second trial for ignition . This is repeated
4 times before a hard lock-out occurs . The Return button must be pressed to
reset the controller and to allow for another attempt .
Once the burner is lit and flame has been proven the boiler operates as it is
4 .
programmed (Service Display =
If the unit exceeds its target temperature and there is still a call for hot water
5 .
the burner will turn off. (Service Display = 1)
If the burner is on to maintain the heat exchanger temperature for DHW
6 .
Comfort mode (Service Display = 7) .
If the burner is on for frost protection (Service Display = 9) .
7 .
MAIN LIT
DISPLAY DISPLAY
OFF -
(blank) (blank)
XXX 2
XXX 3
XXX 4
XXX +
XXX 7
XXX 9
Table 2: Operating Display and Service Display Codes.
for Domestic Hot Water) .
DESCRIPTION
The unit is OFF . Press the space above the Dot for 2
.
seconds to turn on the unit
No Call for Hot Water - Standby
Self-test – When power is applied to the unit the
controller enters a self diagnostic mode for 5 seconds
Fan Pre-purge and Post-purge
Trial for Ignition and Flame Proving
Heating – DHW
Burner on for Comfort mode
Freeze Protection mode
9