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Topic: AquaHot radiator cap part numbers in this post AH (Read 487 times) previous topic - next topic

AquaHot radiator cap part numbers in this post AH

AH radiator cap numbers:
13 lb caps,
Duralast 7013, NAPA 703-1697, Murray 7013

I replaced my cap in 2020 with the Duralast.  My AH has not been keeping any pressure (no leak though) so I just replaced it with a new Murray to see if that will solve the no pressure condition
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot radiator cap part numbers in this post AH

Reply #1 –
New cap in place on the aquahot.  AH up to full temp, still no pressure at all when removing cap to check.

Tank is lipping full to the top.  New 1/4" hose to the overflow tank with new clamps.  No loss of boiler fluid anywhere, tank and overflow tank maintaining same level. 
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: AquaHot radiator cap part numbers in this post AH

Reply #2 –

So i used a vacuum service tool to fill aqua hot and all the lines. Got a lot of air out even though the tank was full

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Re: AquaHot radiator cap part numbers in this post AH

Reply #3 –
The new Aqua Hot heaters have zero pressure tanks,  On older heaters, 7 or 10 pound caps will work if 13 pound is not available.

The important thing is sealing the opening so hot expanding coolant goes to the overflow bottle and fluid returns to the coolant tank as it cools down each cycle.

I bought a new cap recently that did not seal the opening which was flat, not bent.  I purchased a thermostat gasket, cut it to fit the top of the cap, put it in and no leaks.
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