On Dec 30, 12:38*am, frank1492 wrote:
Just heard a loud "whoosh" and the pressure has gone to zero again.
Nothing is leaking. Add that to the clues.

On Wed, 30 Dec 2009 01:25:50 -0500, frank1492
wrote:



I just installed a new pressure tank in my hydronic system. It said it
was pre-charged to 12 psi. When refilling the system I think I did a
good job of eliminating the air as there is little noise when the
circulator is running, plus there is a Spirovent installed.
* I like to keep the system pressure at between 15 *and 20 lbs. but I
noticed the pressure seems to drop back to 0 quite often. Then when I
add water, the pressure seems to rise very quickly. The only thing I
can think of is that I have no air cushion.
* I did not check the tank pressure before installing.
*What is wrong and what should I do? I'd like not to have to drain
the system again.
*Thanks in advance.
* * * Frank- Hide quoted text -

- Show quoted text -

Do you mean the pressure gauge on the boiler, how much does pressure
change from high to low, is your house 1 or 3 story, with radiators I
can not go to zero unless my system is empty, to keep my 3rd floor
radiator full of water I need near 12-15lb and only increase a few
pounds as water heats. Maybe a bad gauge, what was wrong with old
tank, to small a tank and pressure can jump when heated and be
erratic, when our boiler was changed the attic expansion tank was
eliminated and a basement tank installed, but we eventualy needed two
tanks as one was to small and pressure jumped 15-20lb with every
heating cycle. www.heatinghelp.com "the wall" is where boiler pros
are.