How do you check the coolant level, other than the level on the expansion tank? Do you have to remove the cap
to the boiler (when cold)? Is it under pressure when cold?
Thanks, Mike
Mike, With a rag, crack the radiator cap open just a little. If any fluid leaks out, re-seat the cap. The coolant tank is full, Yea!
If no fluid Leaks out, remove the cap. Fill the coolant tank completely full with, in your case, 50/50 engine antifreeze. Distilled water is fine too if antifreeze is not available at the time.
When the burner cycles off, fill the overflow bottle to the hot line. Check the hose from the cap to the overflow bottle to be sure it is fluid tight, no leaks.
You are done no matter the temp of the coolant.
Ok, my stupid question: does the Ah need to be cool to crack the cap a little? Is the tank under pressure?
Thanks, Mike
You can crack the cap regardless of the coolant temp or pressure. If coolant leaks out, re-set the cap. If just pressurized air leaks out, ease the cap off and fill the tank completely full.
If you do it like Rudy explained, you won't have any trouble. I usually did it when the aqua hot was cold, but have also have done it when it is hot.