Big Time Air in Super Store Tank Heating Loop

Bobbyd5067

We've been in this house for 17 years. System has always worked fine. We have a Burnham boiler and a SuperStore hot water tank fired off the boiler. About three weeks ago, we heard what sounded like rushing water in the basement. Turns out it was air in the loop that heats the domestic water in the Super Store tank. We have no noise in any other zone (9) - ONLY the circulating loop on the domestic hot water. Our boiler guy has bled the system three times and even installed a new Taco circulating pump. Today was the third bleed. And promptly at 7:00 pm, the gurgling started all over again. How is all this air getting into the system? It's getting worse by the day!

Big Ed_4

Do you have any heating pipes running under a slab ?

Derheatmeister

Is you reliefvalve to the boiler leaking?

SuperTech

Have you tried replacing any automatic air vents that may be on the boiler or cast iron air scoop? They don't last very long, I replace them any time I have to drain the boiler for service. The air could just be from all the fresh water that was added from purge atrempts. Without working air vents that air will end up in one of the zones.

Mad Dog_2

Pictures of piping please. Mad Dog 

hot_rod

Sounds like either you are not getting a good clean air purge, or air is being allowed in to the system some how. An autoair vent on the suction side of a circ that is pumping at the expansion tank. for example.

Mustangman

What boiler pressure are you running? If its a 2 story house and your pressure is low single digits, you may be going sub-atmospheric. When that happens, you will suck air into the system through auto vents, key vents that are not tight. Just one thing to eliminate.