Radiators not bleeding and water pressure is low


  #1  
Old 10-14-05, 05:40 AM
Adrian Dams
Visiting Guest
Posts: n/a
Radiators not bleeding and water pressure is low

I am new to water heating systems, so please excuse any dumb sounding questions.

I have a three storey house and this summer some work was done on it that entailed radiators being removed. As a result, I now have to fill them all up.

I have turned on the water pump and immediately notice that the water pressure is a lot lower than normal. Normally, it sat at around 100KPa but now it is reading 50KPA (9PSI). What is the likely cause of this?

Thinking that it might be because the system is full of air, I started bleeding radiators. Initially I bled the ground floor radiators (and they are now full of water) and then realised that I should be starting at the top of the house and moving down. Is this correct?

So, I went up to the attic and opened the bleeding valve on the radiator up there. It pushed air for a while and then stopped (actually, I'm not that certain it pushed air - it may have sucked air). Since then, whenever I go and open the valve to see if it has any more air to push, there is nothing at all - no air coming out or air going in.

How do I move forward on this? Any ideas will be very welcome.

Adrian
 
  #2  
Old 10-14-05, 02:23 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,682
Received 41 Upvotes on 39 Posts
Low pressure

Locate the feed line to the boiler. Somewhere in that line is likely a device with a bell shape or at least a domed top. The top will have a screw or bolt sticking thru it. This is the feed valve (pressure reducing valve). It can be any color but most are gold or red. Make sure any valves in that line are open. If they are, & the pressure is still low, loosen the lock nut on the top of the reducing valve & turn the screw in 1/2 turn at a time allowing a couple minutes between adjustments. Check the pressure gauge between adjustments.
 
  #3  
Old 10-16-05, 09:06 AM
Adrian Dams
Visiting Guest
Posts: n/a
Thanks for the response. I have found the reducing valve and have opened the inlet tap (which is just after the valve). Can you give me some advice on how best to increase the pressure? From other reading, I understand it is done by adjusting the screw on the top of the reducing valve. My valve is an armstrong rd-11 which has a wingnut style nut on the top. Do I just screw this one way or the other? Which way should I turn this and is there anything else I should do to properly adjust the pressure.

As another note, I have removed and cleaned the strainer from the bottom of the reducing valve.

Adrian
 
  #4  
Old 10-16-05, 02:30 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,682
Received 41 Upvotes on 39 Posts
Reducing valve

After cleaning the strainer, could you get water to flow? I'm not familiar with that particular vavle but on most, you turn the screw in to increase the pressure. If the wing nut simply acts as a lock nut, loosen it & turn the screw in to increase the pressure.
 
  #5  
Old 10-16-05, 06:39 PM
Harleyro1
Visiting Guest
Posts: n/a
Cool Help please

I have the same situation, and I have bled the radiators, they still have some air because I can't get water out of them (although they are hot). I followed your advice and I have found and I adjusted the screw on the reducing valve, and no response on the pressure guage. The guage is just reading 4 psi. Any other advice that you can give me - I just want to be able to correct this without calling in a plumber (or my Dad).

Thanks!

Rosemary
 
  #6  
Old 10-17-05, 06:27 AM
Adrian Dams
Visiting Guest
Posts: n/a
I think my problem may be the backflow prevention valve just before the pressure reducing valve in the line. What I did was loosen the cap of the PRV to see if any water was flowing there at all. Nothing. So I opened the tap after the PRV (that opens to the head of water in the heating system) and water starts leaking out. I closed that tap and the leak stops. The tap from the main supply is still open but no leaking.

Does it sound to you like the BPV is a goner. I'll try taking it off the line and clean it, or at least replace it. Can only do that tonight, since I need to buy a big enough shifting spanner.

Thanks for the help so far.

Harleyro1, have you openened the tap between the prv and the main heating side? If you have then I would guess you have the same problem I do.
 
  #7  
Old 10-17-05, 07:12 PM
Grady's Avatar
Forum Topic Moderator
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,682
Received 41 Upvotes on 39 Posts
Harleyro1 & Adrian Dams

Before calling for help, make sure all valves in the water feed line are open.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: