Air in the system, pump is on a low pipe loop

[LouiseSJPP]

I'm installing a wood-fired system, and using a header tank for the stove's primary circuit to a buffer tank, gravity driven. That's working fine, flow temp 80°, return 60° with a buffer temp of 50°. The secondary system, with the radiators, is problematic. Because the he

 

[BlueLoo]

Do we complete the story here?

 

[LouiseSJPP]

Sorry, hit return and posted...

..... Because the header tank was there, I used it for the secondary system, but the flow and return run at floor level in the loft, with the header tank in the roof space. There's only 2.5m between the flow and return pipe level and the header tank level, so I dropped the pump down into the bedroom, putting it on a vertical down leg and returning the flow upstairs. header feed and overflow sit below the pump on the vertical leg. It doesn't look good, and it doesn't work. I can't clear the air from the water, despite numerous purge valves.

I can switch over to a sealed system for the secondary, and bring the pump back up the loft, on a horizontal leg but I wonder how long I should run the system to see if the air clears first. It is shifting heat to the radiators, it just makes a bit of noise.

Any advice?

 

[LouiseSJPP]

Do we complete the story here?

It's serialized! Hit Return too early