Two zone system -- one is noisy

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  #1  
Old 10-20-18, 08:26 AM
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Two zone system -- one is noisy

Hello, I've had a recurring problem with my hot water heat. Please see below. Thanks for your help.

Have two zones in my house.

1) Ground level -- Water sounds all the time during call for heat. Very noisy. Cannot find a bleeder valve on this floor -- is that possible that there could be none in one zone? Last year, had no heat in this zone. Called HVAC company and they bled the zone from the boiler and heat was restored. Cannot remember if it was quiet then -- but it is noisy again now. The quality of the heating seems to be fine though.

My questions are: Is it possible that there is no bleeder valve in one zone and only at the boiler? I looked everywhere and I cannot find a valve in the baseboards.

2) Upstairs bedroom floor -- Very quiet, what I consider "normal." A bleeder valve is present and it was recently bled.

Does this bleeder valve operate for the entire system or only upstairs?

I have a 30 - year old boiler and have gotten estimates to get it replaced. However, no one can guarantee the water sounds will be resolved on the ground floor. I'm not ready to pay $7k to get it replaced only to have the same annoying water sounds.

Thanks!
 
  #2  
Old 10-20-18, 08:48 AM
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Don't replace the boiler. What kind of expansion tank do your have - bladder type or conventional steel? If it's a bladder type, you need an automatic air removal device. What is your boiler pressure and temperature?
 
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Old 10-20-18, 09:10 AM
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I attached some pics of the system. Thanks for your help.
Not sure of the boiler type, but hopefully the picture helps.
Pressure is 23 psi and temp 145 F

See pictures in my next post.
 

Last edited by PJmax; 01-20-19 at 04:56 PM. Reason: removed pics
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Old 10-20-18, 09:15 AM
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Sorry the original images were rotated. Here's another try:
Looks like it's a conventional type boiler.
Pressure 23 psi and temp 145 F

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Last edited by PJmax; 01-20-19 at 04:54 PM. Reason: cropped/resized/reoriented pictures
  #5  
Old 10-20-18, 10:42 AM
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m,
As Gil said you do not need another boiler just because of air or noise in the system.

Your type of system is a series loop type and does not require vents on the baseboard. The zones are individually bled from the return line at the boiler.

Each zone on the return has a pump and before each pump you have a blue shutoff valve and a drawoff before that. That is how you bleed your zones.

Isolate the zone you want to bleed by shutting off the blue gate valve which will stop the water from back feeding from the boiler when you open the faucet to bleed the air.

After shutting off your boiler and closing the blue gate valve pressurize the zone to 25-28 PSI and open the faucet on that zone and the high pressure will circulate the water through the zone and force the air out.

Let the high pressure water continue to drain until you get a steady stream of only water and then shut the faucet off.

The key to this operation is maintaining that high pressure during the bleeding by opening the lever on your auto feed valve. This will bypass the auto feature.

When done bleeding shut off the faucet and push the lever back down on the feed valve. You should end up with that 25- 28 PSI in your boiler. Before opening up your gate valve, drain a little more water out slowly until you reach about 18 PSI.

Open up your blue gate valve, turn on your boiler and test.

As long as you have no leaks and your system is not drained for repairs you should be good to go for a long time. As long as no fresh water is introduced into the system no air can get in.

After looking at your pics I see you have a B&G feed valve that has no lever but an adjusting screw. This makes it much harder to get that high pressure you need to properly bleed your zone but it can be done by loosening the nut and turning the screw clockwise to increase the pressure into the system but for the inexperienced this can be tricky because when you're done you have to return the screw to the original setting , give or take.

Again your boiler has nothing to do with your air problem.

Hope this helps a little.
 
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Old 10-20-18, 01:44 PM
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As spott noticed, the B&G automatic fill valve doesn't have a fast-fill lever, and monkeying with the set-point adjusting screw to temporarily jack up the pressure for purging, is inconvenient. But, since your pressure is presently indicated to be 23 psi (a little short of 25-28, which would be ideal), I would go ahead and purge it at the present 23 psi, following spott's instructions. Keep us posted.

The next time you have the system depressurized for maintenance, I would replace the B&G fill valve with one that has a fast-fill lever. My 10-year-old B&G fill-valve (model FB-38TU) has a fast-fill lever, but there are other good brands, such as Watts or Taco. (Automatic fill valves are also called pressure-reducing valves - same thing.)
 
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Old 10-21-18, 01:05 PM
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The next time your system is shut down, summer or whatever, put an air valve on the highest point on both zones, and while your at it, put an automatic air release valve near your boiler. You will be glad that you did.
Sid
 
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Old 10-21-18, 05:58 PM
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Thanks for all of your replies .

Is there any risk of damage or any danger in doing the bleeding myself ? I'm pretty handy but this would be the first time I deal with boiler repair .
 
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Old 10-21-18, 06:22 PM
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m,
What better way to learn.

One more thought. If you don't want to fool with that feed valve you can do this:

If you have access to another faucet in your basement you can get a hose with 2 female ends like a washer machine hose and attach 1 end to your cold water faucet and the end to your boiler drain under your pump and fill your zone that way with street pressure.

Two people might be helpful so if it starts to fill faster than it drains they can work the cold water faucet as needed.

When bleeding shut off both blue gate valves to the zones just in case and then open when done,

Hope this wasn't too confusing, Just another option with your type of fill valve with no fast fill lever option.

Good luck.
 
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Old 01-20-19, 02:39 PM
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Spott:
thanks for your reply. I am finally getting ready to try out your instructions. So in the pic of my setup, I should

1. Turn off the heating for the zone

2. Close the blue valve fully

3. Attach a hose to the red valve and open the valve

4. Initially air will come out. Let it run until water comes out

5. Close the red valve and open the blue valve fully

​​​​​6. Turn on the heating to the zone.

That's it? I have no idea how to adjust the pressure .What happens if I do all of this and the pressure drops to an unusable value? Could that happen?

Thank you .
 
  #11  
Old 01-20-19, 04:35 PM
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Shut both BLUE VALVES OFF to stop water from going to other zone while bleeding. When done open them both up. If you have a main shutoff on your cold water feed above your feed valve you can shut that off while adjusting your feed valve and then open it to feed boiler and then when done shut it back off while you adjust your feed valve back again.

You must raise your pressure to 25-28 PSI in order to bleed properly. If you bleed with low pressure and the water keeps feeding in it's defeating the purpose and will keep getting air bound.

You have a RED B&G auto feed valve before your extrol tank. That's what feeds your boiler. Sometimes they have a lever you can lift to bypass the auto feature. If yours does not it makes it harder to bleed. You must loosen the nut on top and turn the screw manually and you will hear water feeding in.

Watch the pressure until it gets to 25-28 and open drain spigot to bleed. Watching the pressure to keep high, keep bleeding until a steady stream of water comes out.

When done, shut off spigot and feed valve. You should have at least 25 PSI in the boiler. Drain slowly until you reach 20 PSI which will be your operating pressure.

Turn on boiler and test.
 
  #12  
Old 01-20-19, 05:00 PM
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You must loosen the nut on top and turn the screw manually and you will hear water feeding in.
After you are done.....and are letting pressure out of the system.... you will need to reset the valve back to where it was.
 
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Old 02-13-19, 07:23 AM
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Thanks guys... I have a plumber coming on Friday to install bleeder valve for the ground floor zone that is noisy.

The bedroom floor already has one. The plumber said it is the largest one he has seen... It is like a garden hose spigot, 3/4 inch. Is that the standard size or will the plumber probably put in a smaller bleeder?
 
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Old 03-03-19, 03:41 PM
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Saga continues....
Plumber put in a manual bleeder valve in the bathroom of the noisy first floor system. He ran the bleeder for 15 minutes and the sounds almost completely went away.

After one month though, sounds are back to the same degree. The second floor has remained quiet.

So must be an air leak in the first floor system right? How would one diagnose the source of leak? Our basement is finished and all pipes are enclosed in the ceiling.

Going to get the automatic bleeder valves in the summer. Is that the easiest solution?

Thanks.
 
  #15  
Old 03-03-19, 04:30 PM
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I don't see how there could be an air leak into the system - your boiler pressure should be 15 psi or greater than atmospheric - and it is according to your gauge. The temp on the boiler gauge is 140 deg F. Not sure if your boiler is set up for cold start or warm start. But when the burner has run and shut off, jack up the aquastat setting to 180 deg.
 
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Old 03-03-19, 04:53 PM
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I agree. It's a pressurized system. If there was a leak..... there would be water coming out.
 
  #17  
Old 03-03-19, 07:41 PM
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M,
If you had a water leak in that zone it would show up as a pressure drop in the system. You said you are running at 23 PSI and if you have not touched you feed valve it is factory set at 12 PSI. With a leak you would not be maintaining 23 PSI, you would be maintaining 12 lbs. of pressure and you feed line would constantly be cold from fresh water feeding in.

I have mentioned in the past about my thoughts on air vents on a loop system. They are a waste of time and money and do not work or are they needed and can cause more trouble than they are worth. If the vent fails it can suck air into the system when the pump is in operation.

If you have bleed your system properly on a loop system, it being a closed system there is no way for air to get back in unless you feed fresh water in or you have a defective air vent that allows air to be sucked in by the pump.

To see if you have a leak you can shut off your cold water inlet valve to the boiler and if you have a leak, with no water able to be fed back in, you will see a drop in pressure. Just because the noise is in the downstairs zone, the cause can be in either zone or the boiler. The system water is common to both zones when it is circulated back through the boiler. Stay away from the vents and if the upstairs zone has one, close it if possible and see what happens.

Is that older pump on the noisey zone. A bad gasket on that pump could also cause air to be sucked in but not bad enough to leak water.

By the noise being back and the vent installed you can tell it's serving no purpose but different people have different points of view.

The air eliminator that you should have on your supply pipe going out before it breaks off into different zones in the one listed in the sight below and they did not install.

https://www.supplyhouse.com/Spirothe...inators-311000
 
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Old 03-04-19, 09:14 AM
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Thank you very much for your replies.
The plumber is well respected in the community and he advised the bathroom radiator bleeder, saying it is more "homeowner friendly" than one in the basement. Additionally, he said he would have to shut the system to install an automatic bleeder in the boiler return -- he advised that in the Spring or Summer.

You mentioned that boiler return water is common to both zones.. .So why does my upstairs zone always stay quiet? I have only bled it once this season and that time it was optional, and I don't even think I did it right.

If I call a real HVAC company this Spring to fix the problem... Should I ask them to install an automatic bleeder at the return line? Do I need one for each zone, or one in the common pipe when they merge into one?

The gasket and other components you suggested might be the problem --- is it just better to replace the boiler or to fix those only? The boiler is 30-40 years old.

Generally, how easy is it for the HVAC company to find the leak?

Thank you.
 
  #19  
Old 03-04-19, 11:45 AM
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M,
First off, that Spirotherm I suggested goes on the SUPPLY line before that line splits into zones. You only need the one on the main line. I would not put any on the return lines but that's a personal preference.

If the old pump gaskets are the problem you can just replace them or you can replace that whole pump with a wet rotor, one piece pump like the other one you have for a lot less money and eliminate future problems al together.

I'm sure the plumber means well and I hope it works for you but my own personal opinion is that you won't see any difference but I could be wrong.

As far as changing the boiler goes. The boiler has nothing to do with your air problems as long as it is not leaking. If he's draining the boiler I would replace that B&G feed valve with a new boiler feed valve. Below is a sight with your options. I use the Watts but any with a fast fill option for proper bleeding will do.

As far as the upstairs zone being the quite one, if it is air that's causing the problem there is no accounting for where it gets trapped in the system.

If the leak is not visually showing they will go through the same procedure as was suggested to you to try for a lot less money. Every time they try something that doesn't work they'll want to replace a part and try something else. If you take a little time and try as suggested you will be ahead of the game and then if you find something you can have it repaired or replaced if you're not comfortable with doing it yourself and you're not paying for their diagnostic time trying to locate the problem and parts changing.

If he's draining the boiler have him check your extrol tank pressure at the same time for proper air pressure.

Just a suggestion, hope this helps a little.

https://www.supplyhouse.com/Boiler-Fill-Valves-17081000
 
 

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