i had a pipe freeze and burst to my farthest rooms baseboard i spliced the line back together but do i need to bleed the system now or does it do it by its self, i hear a lot of air in the system and it sounds like the water is pulsating through the lines not a steady pressure as it should be my pressure is only around 10-12 psi as it should be near 25 any help would be greatly appreciated thank you

 

Sorta true, kinda... when the boiler is COLD before the water is heated and expanded, the pressure should start around 12-15 PSI. If your EXPANSION TANK is in good shape you will see a moderate pressure rise when the boiler heats up. Maybe as high as 25, but that is actually borderline opening the pressure relief valve. I don't like to see more than 20 PSI when the boiler is fully hot. In any case, 10-12 is a bit low.

SO, tell us the TEMPERATURE of the water when the pressure is at 10-12 PSI...

You probably DO have to bleed. If your air separator and air vent are in good shape and properly piped then you might 'get away' with not bleeding, but not likely.

 

when the boiler is idel and the water temp is at 175 the pressure is 10 when the boiler is running it is at about 18. when i turn the heat on i hear the water almost pulsating through the heating lines

 

and im very confused on how to bleed the sytem i can post pics if will help

 

Yeah, that ain't right... sounds like you need to get the air out.

 

Yes, post the pictures... you can't put them here directly. Set up a free account at Image hosting, free photo sharing & video sharing at Photobucket and upload the pics to a PUBLIC album. Come back here and give us a link to your album so we can view the pics and give some ideas for you.

 

ok ill post the pics there and get back to you i appreciate the help

 

NP ... I hope tomorrow AM won't be a problem, I gotta head out for a couple hours... I'll look for 'em tomorrow morning.

 

Pictures by jarhead853 - Photobucket this should take you to my pictures. yea np thanks for the help tonight again

 

I know Trooper will help in the am but get up early and go buy 2 air vents. Its that little can ontop of the air seperator in pic 2, and I see one I think in pic 1 up by that red electrical box. If you have more then replace them all.
Get some teflon tape, and a boiler drain cap or two. A boiler drain might not close and drip slightly after you drain and bleed.

You will need to turn off electric to boiler and let cool to 100F or so
Shut off water suppy to boiler. Blue round valve in pic one going to fill valve and tankless coil.
Shut valve right above circ. Straight handle pic 5
Drain water from boiler at drain above the one we closed above the circ untill 0 psi.
Change air vents. Put teflon tape on the threads and change quickly but dont cross thread. You will get water out when you remove the vent or vents so have a bucket or towel. And this is why you want the boiler cool.While your at it check the pressure in the expansion tank with tire gauge. 12PSI? If not add air to 12 psi. If water comes out of the air valve replace expansion tank
If all went well open all valves we closed and watch for pressure to rise on boiler gauge to 12 psi.
Tighten the air vent cap down all the way and the loosen one turn or so.
Turn power back on to boiler. Your should hear the air purging out of the airvents.
Make sure all baseboard gets hot.

If not I will be here in AM also. We will need to bleed manually. Post any issues you may have with the above.

Mike NJ

 

i appreciate all the help guys i am turning the boiler off for now and stcking the wood and pellet stoves for the day i need to go to work so i will tr this when i return this afternoon

 

well i replaced the air purge's and started the system up again and my boiler held at about 17-18 psi when running and after a few mins it self filled and i hear no air in the lines now. the system seems to be running ok now thanks for all the help


rich

 

Great! You hit the "Easy Button" !

Good call on the air vents Mike!

 

Great thread. I have air in my lines. Similar system to jarhead with an old crusty looking air vent like in pic 2. Boiler idle is at ~12-13psi and 175 deg F. Checked the expansion tank and it was around 5psi. So increased that to ~10psi. Will that alone help or am I destine to replace the vent following lawrosa's instructions?

 

If your pressure is REALLY 12-13 at 175F, then that is too low. Unfortunately, you can never trust the pressure gauge, so if you wanted to be SURE you would have to verify that gauge with a known good one.

Increase the tank pressure some more. You want 12-15 PSI on the air side.

When you increased the tank, did you drop the boiler pressure to ZERO? Or just check it and add air?

If the vents are leaking and cruddy they might not be working. They need to work in order to get the air out of the system.

So, looks like your issues are:

LOW pressure in the boiler.

Not enough air in the tank.

Defective air vents.

All three need solved.

 

Thanks Trooper for the reply. I only checked and added air to the expansion tank from 5 to about 10psi. But I've discovered another issue. I've got a drip from one of my zone valves (marked Taco 571-2). Its crusty and seeping from between the solenoid (top) and valve assembly (base). That's too big a job for me to replace if I have to drain the whole system, swet the old one out and solder a new one inline. So, will get the air vent replaced when I get the valve surviced. It has a good bit of crust on the top too. Not quite as bad as the one in jarhead's pic, but pretty sure its not doing its job. Also figure it might be a good idea to replace the expansion tank. I don't know its age. It had the smallest amount of moisture when I burped it which I assume was just condensation. But the burp gas stunk to hi hell. Wicked sulphur smell. Would you agree to replace?

 

There shouldn't be any water. If the tank is of unknown age, and you got water, it's probably a good idea to replace. Not too awful expensive...