Air pressure keeps dropping to zero

tim smith

My guess is if you see no water on floor anywhere then you probably have an underground leak on a pipe? just a thought, scary as it may be. Tim

Jeff_107

Air Pressure keeps dropping to zero

Hi - I have a loop hot water heating system and the pressure gauge which was stabilized at about 12 lbs has dropped to zero. I have to put water back into the system for the pressure to rise back to normal. (12psi)

Any suggestions? leak in expansion tank? air in the lines.
The auto fill line is open and working.

Thank you
Jeff

martin

No Pressure

You have a leak somewhere,If you put it in to go back to 0 it has to get out somewhere. I think your auto fill isn't working for that should keep it up to pres. How long does it take to depressuize and how often have you had to fill it.

Jeff_107

Fill it every day

I have to fill it every morning. I check the autofill and water seemed to be going into the system. Do you think the leak is in the expansion tank?

Thank you

Leo

You may have a crack

You may have a cracked boiler and the water is escaping as steam up the chimney. Couple this with a bad feeder as they do fail and you have zero pressure.

Leo

Jeff_107

I emptied the expansion tank and no water

The expansion tank has no water in it - is it supposed to have some - even a little? I hope its not a underground pipe. How would you be able to tell. There is no water under the baseboards or near the bolier.

[Deleted User]

The ohhh ahhhh test define

First off, this can ONLY be done with a high mass boiler. No copper fin tubed pr low mass stainless steel boilers.

Disconnect the circulators electric line.

Turn a thermostat up to fire the boiler and keep the make up water on and keep the boiler pressurized.

As the water is heated and pressurized, it will flow towards the breached piping. CAREFULLY feel the supply and return pipng. You will be able to feel where the hot water is flowing to. If at all possible, isolate the return line with a valve so the water has to flow in a forward direction only. If it is a breaching in a copper line between baseboards, you should be able to feel (ooohhh) the water flowing from the heat source, to and through a section of baseboard. Eventually, you will find a place where the water flows into the ground, but doesn't come up at the next baseboard riser(AHAHHHhhhh!!).

Now, if you don't have access to a non contact infrared thermometer, you tank take your shoes off and shuffle around in your stocking feet to find the hottest floor spot. (ahhhhhh) .

Now its time to do some jack hammer surgery... Put your shoes back on first.

G'Luck.

ME

Jeff_107

Auto fill

I disconnected the cold water suplly line to the expansion tank. the water is on, however it doesn't fill it back up. Is it poosible the check valve in the expansion tank is the problem?

jp_2

what if you

drained the system, fill with air and listen for the leaking air?