KEY
CH
Counter (possible)
F
Fuse
FA
Interference filter
FR
Photoresistor
IG
Main switch
LR
Lock-out lamp (possible)
MB
Burner motor
MMS
Air servocontrol terminal board
MPE
Control box terminal board
UK
MR
Auxiliary terminals
38
ECO 22/2 (Honeywell MT 4...)
ECO 22/2 (Siemens SQN 7...)
8
7
6
5
4
3
2
1
N
MV
TC
TR
TS
TMF
VE1
VE2
Suspended terminal
Boiler thermostat
Ignition transformer
Safety thermostat
2nd st.modul.thermostat
1st st.solenoid valve
2nd st.solenoid valve
230V - 50/60 Hz
230V - 50/60 Hz