HTP Elite XL ELX-800 - Boiler Blocking Codes; Outdoor Sensor Faults; Flow Switch Blocking; High Flue Temperature Blocking

lp-666 Rev. 003 Rel. 001 Date 2.25.20
71
Code Message
Description Possible Remedy
FOU
Outdoor
Sensor
There is an issue with the outdoor sensor. It is
shorted, damaged, or disconnected from the
boiler.
1. Check outdoor sensor connections and wiring. Ensure the
sensor and wiring are intact and that the sensor is connected to
the boiler.
2. Check the outdoor sensor resistance with an ohmmeter. See
table in this manual for correct outdoor sensor resistance.
3. Replace the outdoor sensor.
The following blocking codes will block operation until the control determines the situation safe for boiler operation.
FL
Blocking: Tap
Block
This indicates the ow switch is not activated.
1. Ensure boiler contains water and all valves are open.
2. Check the boiler circulator and ensure it is in good operating
condition (operating, wiring intact, etc.).
3. Inspect the wiring to the ow switch for damage and repair as
necessary.
4. Disconnect one wire from the ow switch and test for continuity
across the switch while ow is conrmed to be present.
5. Remove ow switch and inspect switch paddle for proper
operation.
E07
Blocking:
Flue Temp
This display indicates that the ue sensor
temperature is above 210
o
F. When this code
is displayed, the boiler will not respond to a
demand for heat. When the ue temperature
decreases below 194
o
F, the display will return
to normal and allow the boiler to respond to
a heat demand. The bottom line indicates the
status of the pump. The pump will remain on
when this code is displayed.
Check the ue for obstructions or any sign of damage, especially
signs of excessive heat. Repair as necessary. Run the boiler and
check the ue temperature with an external thermometer. If the
ue temperature on the thermometer does not agree with the ue
temperature displayed in the status menu, inspect the wiring to
the ue temperature sensor in the boiler and repair as necessary. If
the wiring is intact, replace the ue sensor. If the ue temperature
is excessive on the status menu and the test thermometer reads
the same, check and adjust combustion controls on the boiler.
TT
Blocking:
Supply
Temperature
TT indicates there is a demand for heat on
the boiler, the pump is powered on, and the
supply sensor temperature is too high for the
boiler to ignite. This occurs because the water
temperature measured by the supply sensor
is higher than the tank temperature – CH di
setting.
This message will stay present until the water temperature
measured by the supply sensor is less than the tank temperature
– CH di setting.
Blocking:
Supply
Temperature
This screen indicates a demand for heat from
the DHW circuit. The pump is powered on and
the supply sensor temperature is too high for
the boiler to ignite. This occurs because the
water temperature measured by the supply
sensor is higher than the tank temperature –
DHW di setting.
This message will stay present until the water temperature
measured by the supply sensor is less than the BOILER SUPPLY –
boiler supply dierential (5
o
F) or DHW SETPOINT is satised and
no longer calls for heat.
FLU
Blocking:
Blocked Vent
Blocking: Blocked Vent indicates excessive ue
pressure. This code resets automatically after
the high pressure condition is resolved.
1. Assure the ue is not blocked.
2. Check the switch wiring by applying a jumper in place of the
switch. If the code clears with the jumper in place, REPLACE the
ue switch and connect the wires to the new switch BEFORE
running boiler.
WARNING: Do not use jumper to remedy an FLU code. Faulty switch MUST be replaced. Failure to follow this instruction could result in serious
personal injury or death.
E07
Flue Temp
High
E07 indicates the ue sensor temperature
is excessive and above 204
o
F. When Blocking:
Burner Temp is displayed the boiler will begin
to modulate down on vent temp rather than
supply temp.
When the ue temperature decreases below
194
o
F, the display will return to normal and
allow the boiler to modulate back up to 100%
if required.
1. Check the ue for obstructions and any sign of damage,
especially signs of excessive heat. Repair as necessary.
2. Run the boiler and check the ue temperature with an external
thermometer. If the ue temperature on the thermometer does
not agree with the ue temperature displayed in the status menu,
inspect the wiring to the ue temperature sensor in the boiler and
repair as necessary. If the wiring is intact replace the ue sensor.
3. If the ue temperature is excessive on the status menu and the
test thermometer reads the same, check and adjust combustion
controls on the boiler.
Table 30 - Boiler Blocking and Fault Codes