riello burner motor buzzing and then lock out

[swnoel]

Hi to all...

Not sure how things are done of that side of the Atlantic, here in the NE US, a Riello is never set to 100# of pressure, even though nozzles are rated at 100#.

I recently had a Buderus direct vent set to 145# that would continue to lock out, as I increased the pressure to 175# the burner started purring like a kitty... they love pressures over 145#. Please adjust your nozzle size accordingly. This unit had a .50/80W for comparison and burning #2 fuel.

 

[oilboffin]

Slacken the grub screws on the pump if it spins then just tighten the grubs up slightly till you can't spin the pump in it's location then feel it if it's ok leave it at that but tighten grubs all the same say half a turn at a time

 

[Terrywookfit]

Slacken the grub screws on the pump if it spins then just tighten the grubs up slightly till you can't spin the pump in it's location then feel it if it's ok leave it at that but tighten grubs all the same say half a turn at a time[/quot

This should be sorted after 3 1/2 years.

 

[ncb_trained]

Slacken the grub screws on the pump if it spins then just tighten the grubs up slightly till you can't spin the pump in it's location then feel it if it's ok leave it at that but tighten grubs all the same say half a turn at a time

Thank you oilboffin. Nine years later and this advice is still good!

Riello F40 G7Q regularly maintained, flamed out in use, subsequently locking out. Extracted burner from boiler and switched ON. At ignition point (t+12s), sparking well but no fuel spray. LP fuel feed confirmed good. Diagnosed HP fuel pump to replace but this is Sunday, no parts available. Stripped pump down. Found drive gear key compromised resulting in shaft spinning freely. Signs of fair wear and tear but otherwise serviceable in the short term. Filed and hardened a new key (pictured), reassembled everything. Worked first time.

However.... after a normal thermo-shutdown, motor refused to restart with evident current noise (as reported many times above). Turning the fan by hand it seemed there was some kind of "stiff spot" and if the motor happened to stop in the wrong place, it simply lacked the torque to restart. This pump and coupling will be replaced tomorrow so I was going to let it rest, then I found this thread and followed the instructions. Hey presto! What I learned from this:

Always change the nylon coupling whenever you've had the pump off.
When tightening the pump fixing screws make sure that everything is aligned and runs freely.
Do the final tightening with the motor running, one flat at a time. Don't overtighten.