low pressure & sloshing in pipes


  #1  
Old 12-13-04, 12:24 PM
R
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low pressure & sloshing in pipes

Hi,

I have a sealed hot water heat system. The boiler is in the basement and there is one story above this.

I hear what sounds like running water in the baseboard units, usually when the system starts up (i.e. probably still cool in the baseboards).

When I look at the temp/alt/pressure gauge on the boiler it's only reading about 5. I'm thinking that my funny sounds are caused by low system pressure. From reading other postings and talking to folks, it seems like the system should be at 15. I have a slight drip from the gaskets around the pump flange and the flange attaching to the boiler which could be reducing the volume of water in the system (although it seems there should be an auto-fill valve to handle this).

Should my pressure be higher and how should I increase pressure?

I was thinking of dabbing some high temperature gasket repair goop onto my leaky gaskets, at least until spring.

Thanks for any info.
 
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Old 12-13-04, 02:57 PM
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Welcome to the DIY Forums

Your pressure should be between 12 and 15 psig. You need to trace the water piping coming into the boiler, and find the auto-fill valve. It will be bell-shaped and have a stem on the top of it. Turn the stem clockwise to increase the pressure. You should hear water running thru the pipe when you do this.

Creep, don't leap. Make small adjustments and watch the boiler pressure guage. After you get the pressure up to range, you need to go bleed all of the radiators.

Post back (hit reply below) if something is not clear.
 
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Old 12-13-04, 03:34 PM
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Hi Rick,

Thanks for responding.

I have three valves in a row on my cold water feed. The most upstream is what I'm thinking is the auto-fill valve. It looks like a pressure reducing valve, has a little lever off the top. I don't know if this is just a handle for rotating the stem or whether its parallel/perpendicular-to-the-pipe orientation means anything. This is the one I'll mess with.

The other two valves are a maid-o-mist air valve and a pressure release valve. So I'm thinking I've got the right one picked out for the auto-fill.

I've taken the covers off of most of my baseboard units and I haven't found any input or bleeder valves. The only thing I can see is the maid-o-mist valve that's on the input line to the boiler. So I'm a little lost about bleeding the system. Doesn't really seem likely the maid-o-mist valve is what I'm supposed to use since it's just about at the bottom of the system. Should I just keep looking for bleeder valves on my baseboard units? Is it possible that my radiators have no bleeders (built in 1967)?

R
 

Last edited by rviger; 12-13-04 at 03:44 PM.
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Old 12-13-04, 03:36 PM
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If you need more help, please post back.
 
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Old 12-13-04, 03:54 PM
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Saw your second posting after I was fiddling with my response. Please see above for a somewhat lame follow up question.

Thanks.
 
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Old 12-13-04, 04:10 PM
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R,

Of course it is possible that there are no bleeders, but highly unlikely. There should be some way to bleed the system of air, other than the maid-o-mist.

I'd trace the piping as best you can, they usually put the bleeders at the highest points on the piping, so if the feed and return lines drop down to a baseboard radiator, the bleeder(s) should be at the high point on these lines. Air will gravitate to the highest point in the system.

Good luck,
 
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Old 12-14-04, 04:59 AM
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If you have baseboard heat with no radiators you probably have no bleeders... you will have to bleed each zone from the basement using the water spighots. You also need to get the psi. up to about 15lbs. for adequate heat upstairs. Unless you want contant issues all winter, fixing the leak would be wise too, but i know what you mean about wanting to do it in the spring.
 
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Old 12-15-04, 05:27 PM
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Adjusting the auto-fill valve did the trick, although it took just the smallest addition to increase the boiler-gauage pressure reading by about 15 lbs. Do indeed "go slow". My valve seemed to be controlled with lever. I pressed it downwards, depressing the valve stem into the valve and adding water to the system. Thanks to Rick.

I overshot by a couple of lbs and bled off some air from the expansion tank to compensate. Watched it over a couple of heating cycles to be sure it was stable at about 15.

Since the adjustment there is no noise, so I won''t bleed anything just yet. Thanks to George for the spigot clarification. I was afraid of that (and the fact that I might end up removing a fair bit of water from the system).

I'll try to fix the gasket leak without bleeding the system now. I've got some high-temp stuff that I'm going to goop onto the area on the flange/gasket where the leaks are occuring.

Thanks for all the feedback. This was my first time on the forum. Great stuff!
 
 

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