water pressure ?

[steve735]

I'm trying to bleed the top radiators in my hydronics heat system. The boiler pressure guage says about 16 lbs. When I open the bleed valves, air is being sucked in, not pushed out. Can I increase the water pressure at the reducer valve? If so, which way do I turn the screw to increase- in or out?

[imeduc]

You sure the gauge is right ? For a 2 story you need about 18psi on the boiler. Back the lock nut off some and turn slow and just a small amount at a time .turn CW for more psi . You should have to kick up the psi till you just get water out of the top bleeder is all. Dont run the pump when you do this and do it slow slow.

ED

My mistakes dont define me they inform me.

[steve735]

Looking on B&G's site I found the answer to be clockwise to increase the pressure. I did that and the pressure did not move on the guage. So I still can't bleed the upper floor radiators. I did attempt to drain the non bladder type expansion tank with the Airtrol valve opened when it drained. I turned the supply water on and got the same pressure results.

[imeduc]

If the auto fill wont go higher get a new one with a new PRV with it. You didnt say how many floors here ??????? Tap on the gauge. Can you hear water go into it??? at all back off the lock nut and screw the screw down do you hear water then??

My mistakes dont define me they inform me.

[Dean]

I think 16 PSI will raise water almost 37 feet high.
I would say a stopped up bleeder but IF it is sucking air in then it sounds like a bad gauge to me.

[steve735]

I screwed the adjuster two complete turns-nothing. I can still go up (2nd floor) and air is sucked in instead of bleeding out of the radiators. But only just alittle from each one. Why would the airtrol say "ATF12" and the PRV say "set at 12" relief at 30. Are those "12's" the pressure it's allowing in?

There's a 3/4" plug coming off one of the radiator pipes (tee'd in)- couldn't I just put a valve there and hook up a hose to the water supply - just to bleed the upper radiators??

That would not be the correct way, but could I do it?

The PVR looks recent.

[steve735]

Forgot, the guage says about 12-13. It fluctuates a tiny bit when the pump kicks on.

[Dean]

The autofill lets water in until the pressure reaches 12 PSI (cold) then when the water is heated up the pressure will usually increase to aroud 18 PSI or so assuming the expansion tank is operating properly.
IF the pressure reaches 30 PSI, the pressure safety pop of valve should open and let water out.

[steve735]

How hot does it have to get to build up some pressure? Should I crank up the thermostat and get it cooking?

So if my radiators are about half full on the second floor, this could take a while to bleed them (if pressure rises), add more water, heat, bleed them etc.?? Or should I try to fill up the radiators as much as I can through the bleed holes?

[Dean]

Normal operating temperature which is around 140º F for the old cast iron raditors and 180º F for newer fin tube type radiators.

If your 2nd floor radiators are only getting half full then the pressure has to be as low as 5 or 6 PSI.
Either that or the pipe feeding them is stopped up but if that was the case, air would not be sucking back in.

Kinda sounds like you may have two peoblems, an auto feed valve that's corroded and not allowing water to pass through and a pressure gauge that's not giving a true pressure reading.

I would first determin how acurate the pressure gauge reading is by going to a local plumbing supply house or hardware store and getting a pressure gauge that screws onto a hose bib (screws on just like a garden hose)
Screw the gauge onto the boiler drain and open the drain valve to check the pressure.

While you're there getting the gauge you better also get a BRASS hose cap because many times when you open an old boiler drain it will not completely close again and you'll need the brass cap to stop it from dripping.