Skip to main content ↑ ↓
Topic: AH Boiler Tank Pressurization  (Read 252 times) previous topic - next topic

AH Boiler Tank Pressurization

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 Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AH Boiler Tank Pressurization

Reply #1 –
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.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: AH Boiler Tank Pressurization

Reply #2 –
Ok, my stupid question:  does the Ah need to be cool to crack the cap a little?  Is the tank under pressure?
Thanks, Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: AH Boiler Tank Pressurization

Reply #3 –
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.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas
 

Re: AH Boiler Tank Pressurization

Reply #4 –
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.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins