Can't Get Heat on 2nd Floor of Hydronic System; Best Guess is Air -Have Question


  #1  
Old 10-14-10, 02:27 PM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
Can't Get Heat on 2nd Floor of Hydronic System; Best Guess is Air -Have Question

My sister moved into a house where the boiler works great but we can't get hot water to circulate thru the 2nd floor. My best guess is that there is air STILL in the upstairs loop. Facts:

* Hot water circulates fine throught the 1st floor loop.

* There's just one zone. At one point, the pipes simply split off of a "T" where one loop goes to the 1st floor, and the other going to the 2nd floor. They "T" back together before returning the the boiler where there is what I'm guessing to be a balancing valve for each loop just before the "T." I have never seen these before, but I deduce it's the only thing that can allow water to be pushed upstairs.

* We have no drain valves upsatairs, so we open the only valve to bleed the loops and close the one directly below it which stops fresh water from rushing through, avoiding the loop.

* We bled it for 25 minutes one day, then another 40 today and STILL can't get hot water on the 2nd floor. When we bleed the water, it only trickles out.

* When we (what we percieve) close the balancing valve to the 1st floor (while purrging air) to force water to the 2nd floor, it seems to make the loop. But when we turn the system back on, there's no heat to the 2nd floor.

Questions:

1.) Should we put a new pressure reducer in? ...since it is allowing water to only trickle thorugh. Or Is trickling enough to get the air out after all?

2.) These "balancing valves" (I'll call them): are they simply a butterfly flap in there, or must you crank and crank like a gate valve to close and open them (see image blelow)?

Thanks for any advice!! It's COOLLLD up there! -Tony17112acst



P.S. This is the best image I can find online. It is not the exact thing, but it is very close: just a screwdriver slot at the top and no room in that brass for anything else.
 
  #2  
Old 10-14-10, 03:43 PM
M
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,339
Likes: 0
Received 0 Likes on 0 Posts
Your photo seems to show a quarter-turn ball valve. When you shut the valve for the downstairs loop, and open the one for the upstairs, does the upstairs get heat?

What does the boiler temp and pressure gauge read?

Don't start replacing parts, such as the pressure reducing valve, until the culprit is pinpointed.

Are there other valves that could be shut? How many thermostats do you have?

Photos of the boiler area would help.
 
  #3  
Old 10-14-10, 04:46 PM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
* No heat upstairs even when we close off the 1st floor loop with the ball valve.
* The boiler temp is OK, it's 160 - 180.
* Pressure is a super high 25 psi. The pressure reducer screw is all the way loose.
* There's one thermostat and no zone valves.
* There are no other valves that we can find.

-Tony
 
  #4  
Old 10-14-10, 04:58 PM
M
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,339
Likes: 0
Received 0 Likes on 0 Posts
It seems that you have two different problems, possibly unrelated: excess pressure and no-heat on 2nd floor. We really need you to post a series of photos of the boiler and the surrounding piping to see what we're talking about here. Post on a free image hosting site, and link here.

Has the boiler relief valve been discharging?
 
  #5  
Old 10-14-10, 05:03 PM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
It did discharge at first which which is why we turned the pressure reducer all the way down. But it's not pressure releasing now (discharging).

Well, I'm at home and can't get to my sister's place for a day or two. But can you give me some idea what you think may be the problem? I'm guessing that there may be air in the upstairs loop and the trickling isn't enough water pressure to push it out. I can confirm that the install is good; I've worked on my own system enough to confirm everythign's good. Air scoop: correct orientation, expansion tank, pressure reducing valve, air removal units here and there.

We had to drain the boiler earlier for me to cut into the 1st floor loop. We removed a non-supporting wall when she bought the house, so I had to cut a small portion of the 1st floor loop out.

-tony17112acst
 
  #6  
Old 10-14-10, 05:07 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,538
Likes: 0
Received 8 Likes on 6 Posts
Three rules:

1. Never trust a boiler gauge.

2. Never trust a boiler gauge.

3. Never trust a boiler gauge.

ooops, make that 4...

4. Never trust a boiler gauge.

skip... skip... skip... skip...
(that's what a broken record sounds like for you youngsters who don't know what records are)
 
  #7  
Old 10-14-10, 05:17 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,538
Likes: 0
Received 8 Likes on 6 Posts
Three more rules:

1. Never take for granted that the expansion tank has the correct air charge (in the case of a bladder tank), or that it's not water-logged (in the case of a steel tank.

2. Never take for granted that the expansion tank has the correct air charge (in the case of a bladder tank), or that it's not water-logged (in the case of a steel tank.

3. Never take for granted that the expansion tank has the correct air charge (in the case of a bladder tank), or that it's not water-logged (in the case of a steel tank.
 
  #8  
Old 10-14-10, 06:23 PM
M
Member
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,339
Likes: 0
Received 0 Likes on 0 Posts
It sounds like you were bleeding air by opening the boiler drain valve? Check to see if there are air bleeders on the end of the upstairs heat emitters - they are your friends. Bleeding from the boiler drain isn't the most effective place. Can you show us pictures of the ends of all the upstairs heat emitters?

The make-up water "trickling" through the pressure reducing valve isn't the prime mover for bleeding air - the system pressure itself does that.

Loosening the adjusting screw reduces the set pressure, and vice versa. But if the system pressure is already high, lowering the set pressure will have no effect. Was the pressure high before you started fiddling with things?

When you bled from the boiler drain valve (if that's what you did), did the pressure drop like a rock? That would indicate a water-logged expansion tank (steel) or a bladder tank that has lost its air charge. If the expansion tank has lost its air charge, the only way to tell and to correct it is to drain the system.

There are so many questions here. Need photos. If you are located remotely from your sister, she may need to call for some help - or you might have to take a day off.
 

Last edited by Mike Speed 30; 10-14-10 at 06:48 PM.
  #9  
Old 10-14-10, 09:15 PM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
You seem to have many misconcetions, but I am not unthankful for these resposes.

* No, I am not bleeding air from the loop with the boiler drain valve! That's to drain the boiler; I'm purging air with the gate valves that were installed for just this purpose!

* Also, I did mention that there are no bleeder valves (And I DO know they are my friends).

* We also lowered the pressure thumb screw AND drained the boiler to allow it to relieve itslef. Again, the pressure was over 30 and discharging from the relief valve. We turned it down and discovered that even when COMPLETELY loose, it will not go below 25 PSI.

* I know all about the expansion tank. But I have a problem with circulation. Let's say the tank is waterlogged, that doesn't help me with circulation.

* Also the pressure guage DOES match the pressure relief valve discharging at 30 psi.

NJ Trooper, do you have any thoughts on what could be stopping circulation to the 2nd floor given my description besides the other stuff you'd like to talk about?

Guys: I know boiler/hydronic heating fairly well. I just want to know if a faulty pressure reducer can cause poor air purging to a 2nd floor because trickling water doesn't seem strong enough to push the air through. All this other stuff isn't addressing the circulation problem I am asking help for. I KNOW about expansion tanks, I know that the boiler drain isn't used to purge air through the 2nd floor loop.

I am replacing the pressure reducer tomorrow anyway, since it cannot achieve a pressure lower than 25 psi. So I guess I'll get my answer tomorrow.

No one has attempted to answer my #1 question (See question #1 on the initial post plz).
 
  #10  
Old 10-15-10, 06:45 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,538
Likes: 0
Received 8 Likes on 6 Posts
Hi Tony, the reason we are going 'round with this is because before you are able to purge that upstairs loop all the ducks need to be lined up.

Yes, the first thing you need to do is to replace the reducing valve. It does seem from your description that it is defective. Myself would close the manual feed valve, and relieve pressure with a drain valve to 12-15 cold, and leave the manual feed closed for a while to observe that the pressure did not climb back up again. Then I would open the manual feed and observe that it did climb... at that point I would be fairly certain that the reducing valve was leaking through and over pressurizing the system... OK, that's that.

The valve that you pictured in your first post is probably a butterfly valve. The intent is for balancing, but they are tricky to adjust for that purpose. They are also very useful for purging, along with the companion drain valve upstream... which is what I believe you are describing, and it sounds as though you have a grasp of that concept... of putting up a 'roadblock' and 'detour' to force the water through the loop rather than around it. OK, that's that...

Modern pressure reducing valves have a 'fast fill' feature. A lever that can be lifted to bypass the regulation feature of the reducing valve. Some older systems don't have these installed on the valve itself, but rather will have a 'bypass line' with a valve plumbed around the reducing valve.

You are correct that the 'trickle' that is coming through the reducing valve is not enough to push the air through the piping. You need a flow velocity of say... 4 feet/second (about) in order to move air bubbles reliably. The fast fill on the reducing valve should provide this.

So, bottom line, yes, replace the reducing valve, and when done, turn the screw on the butterfly valve perpendicular to the pipe to close, hose on drain upstream of this valve, open drain, lift fast fill to get water flowing through the loop at full velocity.

In some cases, if there is no fast fill valve available, a washing machine hose can be your best friend!
 
  #11  
Old 10-15-10, 07:07 AM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
Thanks!! ...that's what I was hoping to confirm. I just installed a pressure reducer on my home boiler last year and the air came right out (and it does have the fast flow on it). So I'm doin it today ...as long as my sister picked one up as instructed.

Another thing: if I hooked up a washing machine hose up, I can't envision how I'd make the curcuit ...the only way is to connect it to the boiler drain valve. I'm not going to do it since she needs a new reducer anyway, but would that have worked? I'm guessing it would.

-Tony
 
  #12  
Old 10-15-10, 07:46 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,946
Likes: 0
Received 0 Likes on 0 Posts
You would be using a garden hose to fill the system though the boiler drain. The washing machine hose is the gender changer so they will hook up to each other.
 
  #13  
Old 10-15-10, 10:43 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,538
Likes: 0
Received 8 Likes on 6 Posts
'zackly... you can tell droops is from the IT world, talkin' about 'gender changers'! But that's exactly right, feed the water through a boiler drain...
 
  #14  
Old 10-15-10, 11:14 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,946
Likes: 0
Received 0 Likes on 0 Posts
Hah! I'm not from IT, I make custom furniture. I may have spent too much time on my computer though. :P
 
  #15  
Old 10-15-10, 11:35 AM
T
Member
Thread Starter
Join Date: Jan 2004
Location: Harrisburg, PA
Posts: 559
Likes: 0
Received 1 Like on 1 Post
Solved

OK Gents,

I slapped the new pressure reducer in and there's excellent water flow now. The air bled out fine and in a HURRY, and NOW we have heat upstairs!

So the answer to my original question was, "Yes" putting a new pressure reducer in can get the air out if a bad one doesn't (for those finding this in future searches).

Thanks for your input!! -tony17112acst
 

Last edited by tony17112acst; 10-15-10 at 01:15 PM.
 

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