Baxi Luna 310 Fi

TTSNWT

Boiler is used for heating only. No DHW connections.

Fault 9 (60°) neon flashing, pump/boiler will not start. Automatic Air Vent on pump was changed but no difference. Pressure is good. Am running at 1.5 bar (top edge of green). If I bleed a tiny bit of fluid off using the pressure relief valve, the light will stop blinking and the pump and boiler will start. There is no apparent air removal at the automatic vent valve, but if I loosen the cap at the center of the pump I get a very small spurt of air. Still need to bleed a tiny bit at the PRV to get the Fault neon to quit blinking and the pump to start.

This all started after the unit was drained and refilled. Seems to be an air-bleed problem.

Can anyone offer any suggestions?

kcopp

LUNA 310 Fi_Troubleshooting_0.pdf

kcopp

May not have all the air purged out.

TTSNWT

Hi kcopp

Thanks. I have all the manuals available for this thing.

I also believe it is an air venting problem and am trying to cycle it enough times to get the air out. Might take awhile - it is in-floor heating system. Never had this problem before and there is no easy way I know of to effectively purge air out of the system. The only place it can vent is the automatic air vent, and only when that is where the air is. Seems to build up in the area of the PVR because for now if I just crack the PVR for 1/2 second, everything goes back to normal. Perhaps it will just take a long time to get through that tiny Auto Air Vent.

Last few times I have cycled it, the Pump Fault neon comes on when everything shuts down, but I don't have to crack the PVR to get it started again. The thermostat cycles on, the neon is still blinking, but after 30 seconds or so the pump starts, the blinking neon goes out, and the boiler fires, all without cracking the PVR. Maybe I am getting closer to getting all the air out.