What is the proper way to bleed a hot water radiator system?
I just can not get rid of this loud thunk that occurs approx.10-15 seconds
after circulator pump turns on.
Thank You in advance for your help.
I did not have this problem last year. Just a thought about the air. This
is the closest radiator to the boiler. I can stand next to the radiator and
hear the loud thud, if I wait for next heating cycle and stand next to pipes
in basement below the radiator I also hear it there. If the system is bleed
completely should I hear gurgle then flow, a couple of seconds later gurgle
then flow or should I hear nothing??
It is a 1920's home, the rubbing is possible.
I bleed the radiators several time the thud could possibly be a big air
bubble burping.... How could I make sure all the air is out? If the bleeding
well from there you would have to force water through
and purge it down by the boiler on the return manifold.
you use either a pump or a bolier feeder set to the "fast fill" position.
You can prob get it all with the bleeders though as long as you
are getting circulation.
There is no such fitting at the boiler to bleed it from. The fill is
controlled by a Watts Series 1156 valve. I can open this auto-fill valve to
allow water in system but with it goes a pressure increase, the system is
running at 14psi ( the correct pressure to run is 1 lb/1 ft of rise from the
gauge --correct?)( It is 14-14 .5 ft from the gauge to the top of the second
floor radiator) There are no automatic vents installed in the system. What
are your thoughts on expansion tanks: steel tank vs a bladder tank?
14 psi is prob just perfect. I like to jack em up to 18-20 after I service
You will need to install a shutoff valve along with a purge on the return.
is just a tee you thread a boiler drain into.) The water goes out through
and tries to come back through return. You have shut the valve though so it
Instead the water goes out the purge you installed. Attach a hose to it and
run it outside.
Put the boiler feeder into the auto-fill position and water and air will
come out the hose.
You need to keep a close eye on the boiler pressure guage. Try to keep it
right at 20 psi.
If the pressure drops too low then close the boiler drain the hose is
connected too a little.
this will allow the boiler feeder to catch up and bring pressure back up.
When the pressure
starts to build too high (30-35 psi and relief valve blows and makes mess)
you just open
the hose a little to let more water/pressure out. You will find a point
where the pressure will
stay pretty even. Let that go for like 20-30 min. You will hear any air.
Otherwise just bleed the air out of each rad one at a time. Personally I
think you will
get the job done fine this way. I usually go around and do that anyway even
if I bleed
it with purge valve.
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