50
P/N HN-IOM-1 82-0331 Copyright 2009 Mestek, Inc.
Finned copper tube gas boilers & water heaters – Control manual
FAULT EVENT &
INTERLOCK
TERMINALS
CAUSE/Discussion
DISPLAY
Action required to
reset from fault
GAS PRESSURE
(J11A, GAS PR)
Occurs on opening of gas pressure switches connected to
J11A GAS PR terminals. The high and low gas pressure
switches are wired in series. Opening of either switch will
cause this fault.
The boiler is shut down until the fault is corrected.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
GAS PRESSURE
168°F
Automatically resets
control after condition
is corrected
HIGH LIMIT
(J5, HIGH LIMIT)
Occurs on opening of an external limit connected to J5
HIGH LIMIT terminals. The boiler is shut down until the
fault is corrected.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
HIGH LIMIT
168°F
Automatically resets
control after external
limit closes
IGNITION CTRL ALARM
Occurs when the HeatNet control receives an alarm signal
from the ignition control. This could occur on ignition
failure, air proving switch error, or any other fault that
triggers the ignition control’s alarm circuit. The boiler is
shut down until the fault is corrected.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
IGNITION CTRL ALARM
168°F
Automatically resets
control after external
signal ends
INTERLOCK SPARE 3
(J11A, SPARE 3)
Occurs on opening of an external device connected to J11A
SPARE 3 terminals. The boiler is shut down until the fault
is corrected.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
INTERLOCK SPARE 3
168°F
Automatically resets
control after condition
is corrected
INTERLOCK SPARE 4
(J11B, SPARE 4)
Occurs on opening of an external device connected to J11B
SPARE 4 terminals. The boiler is shut down until the fault
is corrected.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
INTERLOCK SPARE 4
168°F
Automatically resets
control after condition
is corrected
IRI ALARM
Occurs when the HeatNet control receives an alarm signal
from the gas valve. The boiler is shut down. If the condition
isn’t corrected within one minute, CALL FACTORY
appears on the display.
Check the gas valve if this fault appears.
The display continues showing the SUPPLY, HEADER or
other temperature, whichever had been selected for display.
The temperature shown is the value detected at the sensor
listed.
FAULT SUPPLY
IRI ALARM
168°F
Requires cycling
the boiler ON/OFF
switch to reset after
condition is corrected
Table 11
Status screen fault displays
(continued)
Troubleshooting
(continued)
9
