Upstairs radiators won't bleed; do I need to add more water?

[booobooo]

I try to bleed the upstairs radiators and they hiss for a while, then nothing. I don't know if the problem is that I'm not waiting long enough or if I need to add more water to the system. I took some pics of the boiler since I don't remember which faucet would add water anyway. Thoughts?

 

[sbgasman]

yes ,your gauge is only reading 16ft head of water,which is enough to raise water 16 ft from your boiler

 

[booobooo]

yes ,your gauge is only reading 16ft head of water,which is enough to raise water 16 ft from your boiler

any way of telling from the pics where I would do that? Is it the knob attached to the bladder? I don't remember.

 

[sbgasman]

it will be where your cold water mains meets the c/h system,can't realy tell from photo's

 

[booobooo]

after poking around i believe it's not any of the knobs but rather the reducing valve in the second pic - the little gold bell. Before I go messing with that, any advice? I'd guess I need between 25 and 30 feet to get the water comfortably up from the basement to the second floor. I think I remember the plumber saying 30 max.

 

[sbgasman]

yes i would guess about 30ft,this is only a guess as it eqates to roughly 1bar,a standard pressure for sealed systems here in england,is this a typical system for usa,damian

 

[booobooo]

alright, I lifted the little copper hoop on the reducing valve. I heard water rushing in and I got it up to around 30. I ran upstairs and bled the first radiator, successfully! Then two more. When I got to the last radiator it was the old story. Confused, I tried the first three again, now with no water any more. I went downstairs and found that the pressure was down low again. I guess it went back to its default setting, which is apparently not enough? But I had a plumber do a big (expensive) cleaning last year. Thoughts?

 

[sooey]

As you bleed the radiators you are letting pressure out of the system, so all you need to do is repressurise again then you should be able to bleed the last radiators. After all the rads are bled you should have about 14/15 lbs/sq inch, so you may need to top it up a little then.

 

[booobooo]

As you bleed the radiators you are letting pressure out of the system, so all you need to do is repressurise again then you should be able to bleed the last radiators. After all the rads are bled you should have about 14/15 lbs/sq inch, so you may need to top it up a little then.

Thanks! I did that and fired her up, so we'll see what happens. My mistake, as I understand it, was going back and re-checking those other radiators.

Here's my question though: I thought the line was supposed to be filled with water. Why was it so easy for me to drain it with just a few little bleeds?

 

[sbgasman]

it's only the water in your expansion tank that needs empty for you to lose pressure

 

[booobooo]

so it's settling at about 14-15 psi, which is just what you suggested. But the reducing valve has a little stamp on it that says "set at 12psi." Is that ok? I think it's just sort of settled but I'd like to know what to do if I find it rising over the course of the night (other than run screaming from the house)

 

[Gees]

The expansion tank should prevent the pressure from rising too far. As the temp rises the air in the tank compresses...