Help with oil combustion settings

[SJB060685]

Strange if you’ve done all of the above. Have you done a vacuum test just by chance?

 

[RayPlumb]

Strange if you’ve done all of the above. Have you done a vacuum test just by chance?

No haven't done vacuum test. Only pulling about 0.5 mtrs from current oil level in tank. But also now a check valve..

 

[RayPlumb]

When I was setting up I ran the boiler with the solenoid connection off and photocell out so I could flush out any air in pipework before coil is connected. So effectively the pump just circulating the same oil round from the pump to the tiger loop in a constant loop and not drawing in any new oil as coil is not is not sending any to nozzle.
On one occasion while trying to figure out where this 2 min bubble was coming from I switched the burner on but had left the isolator near the fire valve on the supply line before the tiger loop closed. Instantly there was loads of air filling the clear suction line...?.
I opened the isolator and the air started to clear the hose filling back up with oil..
Surely with the oil just circulating pump- tigerloop - pump and coil not connected there was no additional oil drawn into the loop, then having the isolator before the tigerloop open or closed should not make a difference...??

 

[SJB060685]

Was the tiger loop completely full? As in top chamber full? I doubt it based on your description.
With that isolation valve closed you would experience a hard vacuum which as I said above can cause gases to be extracted to be pull from the solution, hence why I asked about a vacuum test.
A vacuum test enables you to see the sorts of pressure on the suction line.

 

[RayPlumb]

Vaccum test from pump just under 0.1bar . On switch off drops a fraction and holds
I also removed both suction and return lines from the tiger loop and pressure tested to pump at 2 bar and no leaks.
Changed the suction line connection at the tiger loop as no inserts and the isolation valve on the suction line.
Reconnected and flushed air from lines. Fired up boiler and 2 min later small bubble popping up from return. .....!
Boiler is running fine and good combustion results.

 

[SJB060685]

That vacuum reading is fine. If the burner is running fine then ignore the odd bubble. That’s one function of a deaerator.