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This water heater has several lockout features designed
to prevent the heater from operating in unsafe conditions.
HIGH LIMIT CONTROLS (ENERGY CUT OFF)
Thermostat/Water Temperature
This feature is a part of the gas control valve/thermostat
(see Figure 1, item 11) and limits the maximum water
temperature. In the event of the water overheating, this
safety feature shuts off the fuel supply to the burner. This
ECO is not resettable and the gas control valve/thermostat
will need to be replaced by a qualified service technician.
Blower High Limit Switch
This device is located on the blower (see Figure 6, item
49) and limits the maximum temperature of the blower.
If the blower temperature rises above the temperature
setting, the switch opens causing the heater to shut down.
The switch will auto reset once the temperature drops
sufficiently.
BLOWER AIR PRESSURE SWITCH
This device, located in the junction box, monitors the air
pressure produced by the blower. In the event that the
exhaust venting becomes blocked or sufficiently restricted,
the switch will shut the heater down (see Figure 6, item
47). If the water heater has not gone into a soft lockout
condition, the heater will restart after the blockage is
removed (see "Resetting The Heater Control").
FLAMMABLE VAPOR SENSOR
When using a gas fired water heater there is a risk of
flammable vapors entering the combustion chamber, being
ignited by the burner flame and causing a flashback. In
order to detect such flammable vapors before they enter
the combustion chamber, this water heater is equipped
with a flammable vapor sensor (FVS). It is a chemical-
absorption based sensor that is connected to the gas
control/thermostat (see Figure 14). When exposed to
flammable vapors it will trigger the control to stop the
flow of gas and enter the FVS lockout state. While in the
FVS lockout state the LED on the control will flash the
gas lockout code. (Refer to the "System Status And Error
Codes" section of this manual for an explanation of the
codes applicable to the control installed on your water
heater.) If this error occurs, check around the water heater
for sources of chemical contamination such as: flammable
vapors including gas vapors, solvents, paint and thinners
as well as sources of water and detergents.
Note: Resetting the heater will reset the FVIR circuit if
all sources of contamination have been removed and the
sensor clears. If all sources of contamination have been
removed and the system will not reset, the sensor will
need to be replaced (see "Resetting The Heater Control").
14
SAFETY LOCKOUTS
If there is a problem with the wiring of the flammable
vapor sensor or the flammable vapor interface, the LED
will flash the failure status code (see "System Status And
Error Codes").
* ROTATE LEFT (CCW)
TO REMOVE
www. lochinvar .com
COVER*
FLAMMABLE
VAPOR SENSOR
(PULL TO REMOVE)
Figure 14.
100221773_2000189439_Rev. 01
MOUNTING
BRACKET
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