BAXI LUNA 310 Fi troubleshooting guide
Page 1
Fault
Cause
Suggested Solutions
Boiler does not start
No power at the
▪
Check
120 Vac
at power cord outlet.
no LED's lit.
boiler
▪
Check if main
3.15 amp
boiler fuse has blown.
Boiler does not start
#14 LED not lit
▪
No signal from external control. Remove wires from thermostat connections
but #12 LED is lit.
(call for heat)
1&2 at terminal strip and jumper it. If boiler starts replace switching relay.
Boiler does not start
#13 LED not lit
▪
Open DHW tap fully, has pin moved out from DHW differential assembly to
but #12 LED is lit.
(call for DHW)
close micro switch (green wires)?
No
; DHW flow valve diaphragm damaged
replace. If diaphragm OK clean and lubricate DHW valve rod.
Yes
; check
continuity across DHW micro switch, replace if faulty.
Boiler does not start
Low water pressure
▪
Re-pressurize heating system till pressure gauge reads between
1-2 Bar
but #12 and #13 or
on gauge. Check for and repair leaks in heating system.
#14 LED's are lit.
Primary/DHW sensor
▪
Check DHW/ Primary temperature sensors for cold resistance of approx
faulty.
11 K
Ω
(resistance reduces with increase in temp), replace if faulty.
Pump not operating
▪
Check for
120 V
at pump, if no power and sensors OK, replace main PCB.
▪
120 V
at pump, but pump not turning. Release jammed pump by removing
vent cap on front of pump and turning shaft counter-clockwise. If pump will not
turn. Drain boiler, remove pump head release and clean pump cartridge.
Air in system
▪
If pump is running but the flow switch has not closed, or is "bouncing" up
and down, purge air from the pump and heating system.
Flow switch faulty
▪
If pump is running but flow switch has not closed; has pin moved out from
diverter valve to close micro switch?
No
; flow switch diaphragm damaged,
replace. If diaphragm Ok clean and lubricate flow switch rod.
Yes
; check
continuity across primary flow micro switch, replace if faulty.
Pump running, flow
Air switch not
▪
Check air switch has not stuck in the open position. To check, remove room
switch closed fan
operating
sealed door on boiler and pull suction tube from fan venturi. Gently suck on
not running
the end of the sensing tube, you should hear the air switch operating. Re-
connect the sensing tube and retry lighting boiler, (signal from PCB to fan on
start is via the NC terminals on the air switch). If air switch OK replace PCB.
