Siemens LME7 Series Technical Instructions page 88

Fault
Description of the Fault
Code
7 Loss of flame
10 Wiring or other error
Fuel valve V2 leaking (PME73.840A1)
12
Fuel valve V1 leaking (all other PME7s)
Fuel valve V1 leaking (PME73.840A1)
13
Fuel valve V2 leaking (all other PME7s)
14 Proof-of-closure (POC) switch failure
20 Gas pressure fault
21 High gas pressure fault
Section 7
A flame failure occurred during normal operation.
1. Check the fuel / air ratio.
2. Check the flame detector signal in the presence of a known flame source. Replace the flame detector if it
does not produce the anticipated signal.
This fault is a catchall and can be caused by a variety of issues. See Section 7-3 for a list of all known causes
of this fault. If none of the causes listed in Section 7-3 appears to be the cause, review all wiring on the
LME7 and check to see if a wire is landed on an incorrect terminal.
On PME73.840A1, the downstream gas valve V2 failed valve proving. On all other PME7 program modules,
the upstream gas valve V1 failed valve proving.
1. Bubble test the gas valve to ensure the valve is not leaking. If the valve is leaking, replace the valve.
2. Ensure that the setpoint of the valve proving pressure switch is set to 50% of the inlet pressure to the
upstream gas valve.
On PME73.840A1, the upstream gas valve V1 failed valve proving. On all other PME7 program modules, the
downstream gas valve V2 failed valve proving.
1. Bubble test the gas valve to ensure the valve is not leaking. If the valve is leaking, replace the valve.
2. Ensure that the setpoint of the valve proving pressure switch is set to 50% of the inlet pressure to the
upstream gas valve.
The POC switch is not in the expected state. If a POC switch exists, ensure it is wired to terminal X2-02.4 on
the LME7. On an LME75 burner control, the source of power to the common side of the POC switch must
come from terminal X2-02.3.
If no POC switch exists, either set parameter 237 to 0 or install a jumper between terminals X2-02.3 and
X2-02.4.
One of the gas pressure switches wired to terminal X5-01.2 opened, causing a fault. It is common for both
the high and low gas pressure switches to be wired to terminal X5-01.2, so the fault could be either a high
gas or low gas event. Check the gas supply and open any manual shutoff valves. Check the wiring of all gas
pressure switches. Check the setpoint of any gas pressure switches to ensure the setpoint is set to an
appropriate value.
The high gas pressure switch wired to terminal X2-02.4 (PME75.811A1) or X9-04.2 (PME75.812A1) opened,
causing a fault. Check the wiring of the high gas pressure switch. Check the setpoint of the high gas
pressure switch and ensure it is set to an appropriate value. Check pressure regulators for ruptured
diaphragms or incorrect setpoints.
Page 4
Corrective Action
SCC Inc.