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Vic Smith Vic Smith is offline
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Default another cast iron radiator question

On Wed, 24 Nov 2010 16:47:47 -0800 (PST), Joe
wrote:

On Nov 24, 5:57Â*pm, Vic Smith wrote:
On Wed, 24 Nov 2010 13:04:27 -0800 (PST), Joe
wrote:



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
ever does).


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 Â*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. Â*
My last system had a constant feed from city water through a
regulator.
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
bleeders.
If there's anything about your system that runs contrary to what I
said, follow the manufacturer's advice (-:

--Vic


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
I said.
Can't be otherwise in my experience.

--Vic