Any advice on how to bleed air from defroster?

[Karlsenkystfiske]

I drained the whole cooling system on board. After filling it up I cant get warm coolant past the domestic water heater. I guess there is probably a lot of air inside the defroster tubes that engine coolant pump, and circulation pump between water heater and defroster have not been able to expel. I tried loosening the hoses on the defroster but not much air came out. I do get cold water coming out of the defroster outlet. But as it is cold I guess there little or none circulation. Tried running the engine at full speed for a while hoping it would push through, but no.

i think I am left with the following options:

-Take defroster off the wall and place it as low as possible while engine is running. This should help the air migrate upwards and towards the engine where it hopefully will be released into the expansion tank.

-Take off defroster outlet hose from engine side and hold it up high while I pour liquid into it. Might also push the air towards the engine.

Any experiences on the matter?


I have warm water in the hose to the far left, going into the calorifier. From there on it is cold.



Small tubes, and both entrances pointing downwards. Making tubes the perfect hideaway for air I guess.

 

[Karlsenkystfiske]

So I tried to take it off the wall and kind of wobble it around to see if any air locks would get a move on. No success. Bled off some air and water from the calorifier outlet but then the circulation pump lost it`s grip. I have good pressure coming from the engine to the defroster. But almost nothing gets out. Even when I place it at the bottom of the boat. Defroster have just been cleaned with baking soda and vinegar(thorough rinse water rinse afterwards), so it should not have any buil-up blocking it off. Also it was working perfectly before

Perhaps a strong inline pump could help push the air out? Or should I opt for something with good sucking/lifting action?