HRM Wallstar 15/19 Air in Oil Feed Pipe

I've begun my extension project and have had to temporarily move my oil feed pipe to facilitate laying of the concrete slab to FFL. So that the pipe isn't in the way during future processes, I have run the pipe from the tank, up the wall, over the door head, and back down to the burner, extending it using 10mm pipe and compression fittings.

I have attempted to bleed the fuel line but after many many presses of the reset button I'm still getting mostly air in the pipe.

Would this be down to a faulty connection, the route to the burner, or something else?

According to the user manual, the boiler can be placed up to 2.5m above the tank outlet so I didn't think taking the pipe over the door would cause an issue.

The total length of the run from the tank to the boiler is something like eight metres.

Once the extension is up the boiler will be getting moved to a new location in the extension so the route of the pipe is just a temporary solution.

You can't use the pump in the boiler to bleed the oil pipe - attempting to do so will just knacker the pump. You might have already damaged it. All your joints need to be absolutely airtight, or it'll draw air into the fuel, and you need to use an oil line suction pump to draw the oil through into a suitable container until it runs free of air. Going up and over a door is far from ideal though

Thanks, so where would I attach the suction pump to the oil line? I assume as close to the burner as possible, and reconnect once I am sucking oil with no air in it?
Then turn on boiler and I assume the pump can manage the job of pulling the oil the last few inches? As long as I haven't knackered the pump, that is!

Once the slab is laid I could move the pipe back down but there is a high risk of damage so I would prefer to leave the pipe above the door until the boiler is relocated.

Remove hose from burner, suck oil through, turn off oil isolation valve, remove pump, reattach hose, fire boiler. Might need to loosen the air bleed screw on the pump for a few seconds once it's spinning