Tip & How-To about Heating & Cooling

How to Bleed Radiator

If you have a water heating system where you use hot water to heat your home, you may have to bleed your baseboard radiation or cast iron radiators which ever you happen to have installed in your home.

Any time you let the pressure out of your system you can get air into it. For the system to work properly and quietly you need to release the air out of the system.

To properly bleed air out of your system you will have to make sure that the pressure reducing valve is working correctly and is keeping your system pressurized properly.
This tip will tell you about that and shows you a picture of what it might look like.


The next thing is to find the bleeder valve or valves on your system. Some systems will have many bleeders. Cast iron radiators will have one on each radiator near the top and baseboard heating systems will have one per loop at the highest point of each loop. When you open the bleeder you will get a foul smelling air out of the bleeder valve. Leave the valve open as long as air is coming out of it. If it is spitting and puttering, leave it open and catch the water till it comes as water only. This process can take a long time for some systems.

To open the valves sometimes you may need to use a special tool. Some valves have a four sided stem and others may have different configurations. Some you can get too with a needle nose pliers and others will accept a screwdriver. Many of the special tools can be found at stores like Lowes or Home Depot. HVAC supply houses often have them also.

The bottom line here is that air in your system is not good it will decrease the heat output of your system and you will hear the water running through the system when it should be very quiet. Releasing the air from your system will ensure top efficiency and performance of your heating system.



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my boiler heating is working but hot water is not coming. i want to know how to set hot water 24 hours 7 days

As I understand your question, you have a boiler with a 'summer/winter' hookup for domestic hot water.

Your boiler should run all the time, i.e. not be shut off by you. Your boiler provides hot water for baseboard heat in your home ... possibly through several 'zones' each controlled by an individual thermostat and circulator. Yours may be a steam system. If this is the case, you have radiators not radiant baseboard heaters and no circulators.

Your summer/winter hookup provides a constant supply of domestic hot water. It does this by taking cold water from your water main and passing it through a copper coil which sits inside your boiler and then to your hot water main in your home. Since the coil sits in the hot water at the top of the boiler, it is constantly being heated. This coil may be in a deteriorated condition in your case or it may be too small for your needs.

Several years ago, I did a small upgrade to my mid 1950's era American Standard boiler. The summer winter hookup in my case was mounted on a 4 inch cast iron boiler plug. The coil was 12 feet long (folded up to a package about 1 foot long). I was very afraid when the plumber came in with what amounted to a 10 foot long pipe wrench. My fear was I would have a pile of broken cast iron at the end of the day. All is well that ends well. He got the old one out and replaced it with a coil that consisted of 20 feet of copper tubing 3/4 inch in size (the folded tubing was about 20 inches long and fit nicely into the boiler). We now have all the hot water a household consisting of one guy and three gals would need in all but the extremest of times..

I think you r answer is here ... replace your summer/winter coil with a new, bigger coil.

Something else I did. My kitchen is 60 feet (pipe wise) from the boiler. It takes a long time to get hot water there. I put in a small electric hot water heater just under the kitchen. I put a timer on it so it runs for a couple hours in the morning and a few hours in the afternoon. The hot water line from the boiler serves as the cold water input to the heater. I now enjoy the convenience of quick hot water in the kitchen with the relatively low cost of oil heated water from the boiler as a relatively small cost of electricity.

My winter settings are 160 - 200 and my summer settings are 120 - 150 which seems adequate for our needs.

Thanks for your question at FixYa.com. I hope I have been of assistance to you today.

Feb 05, 2011 | Heating & Cooling

1 Answer

Steam Cast iron raditor makes a loud popping or banging sound.

Some cracking and pinging is normal due to the thermal expansion of the metal. If some make more noise than others, it could be an indication of a plugged or restricted steam vent (the chrome gadget on the side of the radiator) or that the return line at the boiler needs draining or that there is too much water in the supply lines. A good flushing of the supply and return lines will help. Check your water level after flushing. I would replace the original steam vent on the suspect radiator and see if that helps, it could be over heating.

Jan 31, 2010 | Honeywell Programmable Thermostat Heater

1 Answer

Some of the baseboard heaters don't get hot. It is an old (1970) boiler system. Is there somewhere on each individual unit to turn it on? I'm baffled, I just assumed the hot water would run through all of them, but some are just cold....not getting any heat. The brand name on the front of the boiler says 'Ack O Matic'. It is natural gas.

No the water does not have to run through all of them....if you have what is known as a mono-flo system.
With this type of system there are tees that divert some of the water to the radiator and some of the water bypasses and goes on to the nest radiator and so on....

If you look on the radiators that are not getting warm or any of the rads for that matter you will see a silver bleeder valve. Some of these take a "key" to open and some just have a screw driver slot.
If you open the beleeder you will probably get air out of the radiator. Leave the bleeder open till the valve spurts water out, then close it.
Continue this until all the rads are full of water.
If no air or water comes then your "fill Valve" on the boiler may be faulty and not allowing water into your system. You may need to replace that and then bleed the rads.....
Bottom line.... air does no heating, the rads must be full of water to make heat. Air in the rads also air locks that loop in a mono flo system...thus no heat...
Sometimes even after bleeding it can take sometime for the water to start flowing through a rad again... be patient...

I hope that this will help you to solve your problem!

Thanks for using Fixya!!


Dec 14, 2009 | Heating & Cooling

1 Answer

we had a powerflush yesterday,today we have no hot water when we put water on its making alot of noise banging etc? sounds like air in the tank or pipes?

Sounds like you have a boiler type heating system and when it was flushed air got in the system. If you don't have automatic air bleeders in the system then you will have to bleed the air out manually. On the radiators depending on the style there should be a nut with a screw in the middle(on most cast iron radiators) or a elbow with a bleeder (on most radiant baseboard slant fin style)

Dec 11, 2009 | Desa International CBN30T Central Heating...

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