I've got a seperate loop of my wood boiler system that goes to a
little used upstairs bedroom. It has a shut off where it branches off
the main line to the house. It has always worked fine, and I just just
bled it last week until water came out the bleeder. Now I cant get any
water out (I can hear air) , and I can hear the water (or air bubbles)
gurgling around in the radiator and pipes. I've tried bleeding it with
the main line to the house closed off to increase pressure going to
this bedroom loop, but nothing works. Its very strange, since it just
worked last week. It is getting some water, as parts of the radiator
are getting hot. Sometimes it sounds like the water is actually going
down when I open the bleeder instead of up. I have noticed a suction
on the bleeder screw at times though most of the time air definitely
comes out. My boiler is full.
I heard similar sounds when I was running the boiler pump off an
inverter once during a power outage, and the pump couldnt run full
bore. BUt my pump is working fine in the rest of the house (fine as it
If the radiator is the highest in your system and you had it filled
before, you lost water or had air in the system elsewhere.
Loss of water could be from a leak, a relief valve popping, or more
rarely an expansion tank taking on water.
If you had air trapped it worked its way to the top.
My last system had a constant feed from city water through a
Some you have to open a feed valve.
If you're sure you're not leaking water anywhere you have to open the
feed valve when you bleed radiators.
The radiator will fill.
Start at the lowest radiator and work your way up.
Bleed each until no sputtering and you have a solid stream from the
If there's anything about your system that runs contrary to what I
said, follow the manufacturer's advice (-:
Yes its the highest.
OK there are two valves in the loop having the problem. One is a ball
valve at the very beginning of the loop, the loop is about 30 feet
total (10 feet over and 5 feet up, times 2). There is another, very
old valve attached to the radiator itself. That valve has always
leaked slightly, on occasion. So air can get in there, but its always
been able to and I've always been able to bleed it. I'm guessing its
part of the problem though I dont understand why the level wont come
up when it did a week ago. the valve leaked then too
I dont know what a feed valve is, and I dont think I have one.
It's a fill valve. How you get water into the boiler.
If city water pressure is higher than what the boiler manufacturer
wants, they supply a regulator between the city supply pipe and the
boiler to lower the pressure.
That's my experience, and I've had regulated and unregulated in the
same city, so it's a boiler design issue.
I don't know anything about well water supplies.
Except for the leaker, which you should get fixed, if the valves are
open you should have no problem.
If the leak is at the valve stem it just needs new packing, but you'd
have to lower the system water to below the valve.
A typical radiator holds some gallons of water, and I assume the leak
from the valve won't empty the radiator in the time span you're
talking about, but only you know that.
That's the trouble dealing with incomplete information.
I don't know if the valve is dripping constantly, or just shed a drop
or two when you open or close it.
Think you said it was a new boiler, so chances are the radiators were
never bled properly by the installers.
And since you can't get water out of the top radiator, your fill valve
isn't opened, which means you probably don't have a regulator.
Just a valve from your water source to the boiler, the same source
that supplies your sinks and tub.
If that valve is open the water will fill the entire system if bled as
Can't be otherwise in my experience.
Thats not a problem. ;-) It is a stem leak and its at the very top of
the system. Strangely though, when I went back and tried it I
successfully bled the radiator. I only opened the ball valve a crack,
and that seemed to work better than opening it full. or some other
random event is taking place that I dont understand. Anyway its
working for the moment. Problem is I will probably have to do this
every time I heat the room, which is only s afew nights per week.
Its a slow, steady drip.
No, I've bled the radiators many times since I got the boiler. My
boiler only gets filled when I take the hose out and fill it manually.
Its not hooked up to my water lines and there's no regulator like my
old pressurized boiler had.
Meaning there is a tank at or above the highest radiator and the tank
has an open top? If that is what you have the tank water level has to be
above the highest radiator.
Other wise there should be a tank that has an air cushion. As water and
the pipe expand at different rates the water has to have somewhere to
go. I goes into the tank and compresses the air. The other thing this
tank does is pressurize the system. The compressed air maintains the
pressure. If the tank doesn't have a diaphragm to separate the air and
water the air can dissolve into the water and the air cushion
disappears. Then you close the valve from the system to the tank and
drain the tank. This is similar to a well system. The open top tank does
the same thing.
If you don't have an open tank above the top radiator there should be a
pressure gauge. You fill the system to a pressure at least 1/2 psi for
each vertical foot from the gauge to the highest point in the system.
If the water (not bleed) valve at the radiator is leaking it should
never let air in. The pressure should always be positive so water would
I don't see how the system will stay reliable. Most of the system
operates under a vacuum. I expect that over time you will accumulate air
in the radiators. You can't bleed any radiators (air will go in).
I'm done giving standard radiator advice to Joe, because I have no
experience with this type system.
When he said he filled the "boiler" with a hose through a hole in the
top I said "Whoa."
Joe, you have to go to the company who put this boiler in to get any
It's probably a one-off system too.
I've seen them advertised, and one place nearby has one sitting on a
trailer to advertise it. That's all fine and dandy, the one I looked at
was a *normal* pressurized system. Why your system isn't pressurized is
the really strange thing. Like I said before, get the guy who installed
it to work on it. Only way I see of maybe making it work is to use a
pump instead of a circulator.
buffalo ny: in my three story building, the fresh water feeder must be
open, the circulating pump must be on, and the burner must be on for
there to be sufficient pressure for the water to reach the top floor
to allow the air to be bled out.
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