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Old 01-21-2008, 05:20 PM  
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Default Boiler Somethings not right

Need advice again. House over 100 years. HVAC man cleaned and repaired boiler past few months ago. Before maintenance, radiators worked GREAT for the past twenty years. Now some radiators are hot, some warm, and steam is not reaching others. Any adivce or call back HVAC. Thanks again. This site is great!!

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Old 01-21-2008, 05:33 PM  
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First check to see if they shut those radiators off during the maintenance for any reason, and forgot to turn them back on. I realize you probably already check that first thing, but I have to make sure. That said...

Steam means you would have one pipe from the floor going into the radiator and a steam valve. Is that right? If so, steam the valves may need replaced. If they are old and almost ready to go, the disturbance from the maintenance was probably enough to due them in.

The little hole in the valve, where the steam comes out (the orafice) is a specific size, depending on the distance from the furnace - larger hole for those farther from the furnace, and smaller for those closer. On those which don't work properly, remove the valve (turn of the large inlet valve at the floor first) and take them to the hardware store. You don't have to get the exact same style, but you do need to match the size of the orafice.

This is one area where I'm no expert, so I'm sure others will be along shortly to offer more insigt.
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Old 01-21-2008, 06:05 PM  
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Hello Marie:
Your systme is air locked and air can't heat, only the steam. You need to find an air relief valve (usually automatic) and make sure it is open. Sometimes they sit there and jiggle like the thing on your pressure cooker. In many systems there is a hydroscopic valve on each heater; they wear out, rust up and sometimes just give up. There will be a slotted screw in that valve and you can loosen the screw a little to allow the air to escape; just be sure you turn it back down when the steam comes out. Caution: do not let the hydroscopic screw come all the way out and don't open the system in any way with steam pressure on it. They will scald you like my mother used to do her chickens after she rung their neck; made the feathers almost fall off. So, keep the feathers you have and don't open the system under pressure.
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