I would like to know what exactly bleeding a radiator is, or does. Our radiators knock, and knuckle a little when the heat comes on. Other HO’s (snicker snicker) have suggested getting a radiator key from Lowes, etc…. and bleeding them to let any air out. Apparently this should be done once a year? Anyways, new homeowner hasnt a clue.
Thanks guys.
Replies
With the amount of work that we are doing on our house we end up draining the radiators a few times a year. After running the boiler we need to bleed the radiators a few times every time after filling the system to remove all the air out of the system. If a radiator has too much air the water will not circulate to that one and it will no longer get hot. Our boiler has a pump so when the level in a particular radiator is a little low we hear sloshing as the water is pumped through and sloshes over and past the fins.
Knocking and pinging usually is not an issue solved by bleeding the radiator. The knocking and pinging is from the cast iron body of the radiator expanding from the heat and shifting on whatever it is mounted on. Our freestanding radiators are completely quiet. Baseboard radiators that I have lived with in the past have been noisy as the main tube expands and contracts against the rivets and bolts.
regards
cledwyn
>>Other HO's (snicker snicker) have suggested getting a radiator key from Lowes, etc.... and bleeding them to let any air out.
Now, if they tell you to go looking for snipes ....
Actually, that is just what you have to do - but go to a real hardware store -they need the business AND the person there can give real, knowledgable advice.
Short version - get the key and take a can or bucket to the highest radiator.
Hold the can under the valve, crack it open and let the air escape, catching the water that spits out and then streams out in the can. (or let it squirt on the floor, whadda I care {G}!)
Close it up when the stream comes out.
Work your way down, highest to lowest.
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Oh yeah, I forgot that part about needing a real hardware store. Back when I still bothered to try, I checked HD, Menards, Lowes and none of them knew what a radiator key was, or if they did, they could just say they did not carry them. Same deal if you ever want to replace the radiator valve, or the bleeder valve.
Living 2 miles from 7 Corners Hardware sure has it's perks!
I assume you mean cast iron radiators with hot water (not steam)?
Doubt the bleeding will help with knocking.
Knocking is probably more related to the radiators and pipes shifting on their mountings (or rubbing on floors or framing) as they expand.
Does not mean your radiators would not otherwise benefit from bleeding. Odds are good that they would.
Can we assume this is a hot water, rather than a steam, system? If this is a chronic problem, talk to your plumber about a device (I think it's called a Spiravent.) that automatically scrubs air out of the system. Apparently there are several benefits to such a device.
Al Mollitor, Sharon MA
Go to http://www.heatinghelp.com there are great FAQ's and some inexpensive books available. You will have any system running smooth in no time....that's not a mistake, it's rustic
As has been asked, if steam heat then you should check the steam valve vents on the side or the radiators. IF you need new ones DO NOT get them at HD, they only cary junk. Go to your local plumbing supply house and get the best brand they carry, will be like $6-$8 each. As has been said if you do have hot water then you should get a radiator key at you local hardware store. Drain ALL the radiators in the house. While the radiators on the top floors are more likely to have air in them, the other radiators do get air in them ocasionaly. Especialy if they have not been bled in a few years.
As for the noise. What the others said is correct abought the rubbing. However the best way to reduce the banging is to insulate your pipes. The more pipes you can cover the less thermal stress the pipes will go through as they heat up and cool down. Use fiberglass pipe insulation instead of black foam. Its a little more money but it is a better insulator and wont melt if exposed to the really hot pipes near the funace. BTW the FG pipe insulation is densly packed and wraped in a white papper so its not as itchy as you might think.