Faulty Primary Circuit (No water or absense of Flow)

[Andyfbt]

I hope one of you can help me.

My gas boiler is a Biasi Active A 18S. The boiler keeps cutting out while starting up due to the error 'Faulty Primary Circuit (No water or absense of flow)'.

It's not a new problem. In the past I was getting the same issue but then it seemed to fix itself and the boiler would work each time, I even had a serviceman out to perform a service and he certified it as fine. But latelly the fault has been happening everytime I try to turn on the boliler. Usually it will get a spark and ignite and start heating up but then often cut out with the mentioned fault. I can eventually get past the issue after about 20-30 minutes of switching the boiler off at the electric switch and then back on again everytime it goes to the error, eventually it works without going to error.

However, yesterday I had to bleed some radiators because most of them were not working correctly any longer, some not at all. I bled the first radiator, it made a hissing noise for a good 2-3 minutes before water came out. For the other 3 radiators I bled after, they only made a small hissing noise and NO WATER came out at all from any of them, which I thought was strange as I always understood water should come out.

Now when I am trying to turn on the bolier it starts up but doesn't even try to spark/ignite. It is just going very quickly to the error 'Faulty Primary Circuit (No water or absense of Flow)'.
Turning off and on at the electrics is having no impact this time.

Any guideance on what the issue might be is appreciated (I obviously would like to avoid paying for serviceman again if it can be avoided!)

 

[algas]

If yours is a pressurised system you may have dropped the pressure too low by venting the rads, or if not pressurised the header tank may have run dry due to the ballvalve sticking, either re-pressurise with the filling loop or re fill the tank, vent the rads then re-pressurise again to 1.5 bar, you may have to vent the pump also re-set the boiler. If this is a re occurring problem you could have a slight leak on your system or maybe dirt in the pump.