Hot Water System Top Zone (3rd Floor) No Heat After Purge


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Old 11-05-13, 08:34 AM
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Hot Water System Top Zone (3rd Floor) No Heat After Purge

I have a four zone hot water heating system. I am currently not getting any heat up to the top floor - the basement, 1st and 2nd are fine.

Starting with a fully drained system and with all valves in their off positions, I turned the boiler on, filled it by opening the main fill valve and let it come up to temperature/ pressure (210/16 respectively). I then shut the boiler off and leaving the main system fill valve open, lifted the lever on the pressure reducing (bell) valve.

Starting with the basement, I attached a hose to the purge spigot on the return, opened both the spigot and the corresponding fill valve and allowed it to run until no air bubbles were present in a bucket for about a minute. I closed the spigot, opened the return valve below the purge spigot and then repeated the process for the remaining 3 zones.

I closed the pressure reducing valve and turned the boiler on and proceeded to go zone by zone starting with the basement and working upwards, turning on the corresponding thermostats. The basement, 1st & 2nd floors all received hot water and the heat worked fine. The 3rd did not. I removed the thermostat and jumped it to rule out any issue with it.

I shut the system down again, isolated the 3rd floor zone and repeated the above process to no avail. I received hot water from the boiler through the return spigot so I was sure water was circulating through the zone freely and without air.

I let the system run for a week hoping the problem might resolve itself but it did not. I am at a loss. The one difference now is that when I attempt to purge the zone (with the boiler off, zone isolated, fill valve on) the water will just stop flowing. I left the purge spigot open for hours thinking that it might be a large amount of air that needed to be removed - nothing happened still. Now whether I was supposed to do either of the following the point is moot because I did, but while in this purge setup if,

A - I flip the switch on the boiler to the on position, water immediately begins to flow out the purge spigot

B - with the boiler off, if I manually slide the motorized valve below the purge spigot to the left ,water also immediately begins flowing out the purge spigot above (that seems odd).

Help please!
 
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Old 11-05-13, 09:15 AM
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A few things need talking about first...

Under presusmption that temperature gauge is somewhat accurate:

Why are you running the boiler at such a crazy high temperature?

Find the aquastat on the boiler and turn that high limit DOWN TO 180F !

In the one picture it appears that you've got the boiler up to TWO HUNDRED FORTY! degrees! How did you do that?

Next... NEVER introduce cold water in any quantity such as for purging air out into a HOT boiler! This is a sure recipe for a cracked boiler. Cold water hits hot metal ... C---R---A-/\/\/\-C---K ! I sure hope you didn't.

ALWAYS shut the boiler down and allow to cool to 100F or LESS before beginning any purge operations.

Starting with a fully drained system
Why was the system 'fully drained' ? Unless there was something being serviced that required draining the system, there is NEVER a good reason to 'fully drain' a boiler. That smelly old water should remain in the boiler. There is more harm to be done by draining a boiler and introducing fresh water than just leaving the water alone.

more later...
 
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Old 11-05-13, 09:19 AM
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Mike, is this in a commercial building?

You should be aware that in multi-tenancy and commercial buildings, that parts of NY require only LICENSED PERSONS work on heating systems.

Do you OWN this equipment?
 
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Old 11-05-13, 09:41 AM
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It is a legal two-family that I own. I reside in the top 3 floors and use the garden level ("basement") for my office.

I am cautious about letting the boiler cool down before undertaking the purge. Have I ever screwed up? Possibly, but not that I recall.

There was a leak from the circulator pump to the supply lines (original piece was some threaded multi-material mess of a thing) that need to be replaced at the end of last season. It was drained for that purpose.

I'm not sure why it is set so high. You are right, I should have caught that. The water is definitely much hotter than it has ever been - a thought I had, but failed to follow up on. I am correcting it now.

Thanks.
 
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Old 11-05-13, 10:05 AM
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Aquastat

It was set at 180 degrees but it is running hot.
 
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Old 11-05-13, 10:29 AM
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Ok... it seems you may want to investigate the accuracy of the high limit device then. You don't want that running away on you!

I believe that the reason you can't get flow to the 3rd floor may be a 'static' pressure issue. You may have to raise your cold fill pressure by a few psi.

If you can closely guestimate the 'altitude' difference between the boiler and he highest point in the system, you can determine what your cold fill pressure should be.

Multiply the feet of height of the highest point above the boiler by 0.432 and ADD 4 PSI. This is what the cold fill must be in order to get water to the top of the system and maintain a few PSI of pressure at the top.

Say 33 feet from boiler to top... times 0.432 = 14.25 PSI plus 4 PSI for 'headroom'... and you come up with 18.25 PSI MINIMUM required pressure for your system.

DON'T TRUST YOUR BOILER PRESSURE GAUGE! Read this:

http://www.doityourself.com/forum/bo...ure-gauge.html
 
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Old 11-05-13, 12:07 PM
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Ok - you were pretty close with the 33 example! I came up with 34 feet from the boiler to the pipe on the top floor of the building. That works out to 18.7 PSI.

I found this thread where you responded to somebody asking how to safely raise the cold-fill pressure but the information seems to be missing. Or am I missing it?

You do say "at least" - how much becomes too much?

http://www.doityourself.com/forum/bo...-pressure.html

I will build a test gauge ASAP but I think I need to take a shot today at getting this running.

Thanks again - I really appreciate it.
 
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Old 11-05-13, 01:11 PM
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I found this thread where you responded to somebody asking how to safely raise the cold-fill pressure but the information seems to be missing. Or am I missing it?
I guess I didn't post it because one of the posts he seemed to have already done it.

You do say "at least" - how much becomes too much?
"MINIMUM cold fill" is better terminology.

When the boiler is as cool as it gets, the pressure should not fall below the minimum. Since we are adding 4 PSI as 'headroom', you do have a bit of windage to mess with. 18.7 PSI could actually be 18 or 19... we don't need super accuracy, but enough to know that there will always be a positive pressure at the top of the system.

You know that the boiler pressure increases when heated... and you also know that you have (most likely) a 30 PSI safety relief valve. (some boilers may have higher pressure, but 30 is 'standard').

If you increase your minimum pressure your MAXIMUM pressure will also increase proportionally.

If you have a 30 PSI relief valve on your boiler, it should only be operated up to 10% below the max, or 27 PSI.

If after increasing the MINIMUM to 18-19 PSI you find the pressure when HOT goes above 27 PSI, then THAT is too much.

The remedy for this would be servicing the expansion tank to make sure it's doing it's job, but in some cases a larger expansion tank may need to be fitted.

You can manually increase the pressure temporarily by lifting the fast fill handle on your pressure REDUCING valve (the fill valve) and adding a few more PSI. If you find this solves the problem we can talk about asjusting the pressure reducing valve so that it maintains that pressure automatically.
 
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Old 11-05-13, 01:37 PM
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I always fill with the pressure reducing valve in the open position so that will not help.
 
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Old 11-05-13, 01:51 PM
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Does it matter what position the valve on the expansion tank is in when filling the system?
 
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Old 11-05-13, 02:19 PM
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I always fill with the pressure reducing valve in the open position so that will not help.
I don't understand what you mean Mike?

The pressure reducing valve is a 'regulator' that will maintain system pressure at a minimum setting, typically for a home up to 2 stories tall, 12-15 PSI.

In your case, a taller home requires a higher minimum.

There is a lever or handle on the valve that BYPASSES the regulation part of the valve. This is called a 'fast fill' lever.

Not all reducing valves have a fast fill though, so perhaps that's what is confusing us here.

Looking at your pics, I don't see the pressure reducing valve. Can you show us a pic of your pressure reducing valve?

I do see the pressure RELIEF valve at the left rear on top of the boiler... don't get confused between RELIEF and REDUCING...

Does it matter what position the valve on the expansion tank is in when filling the system?
If you are talking about a valve on the pipe between the boiler and the expansion tank, it should be OPEN. The only time that valve should be closed is when servicing the expansion tank.

I don't see the tank in your pics either, can you show us?
 
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Old 11-05-13, 03:33 PM
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Yes, the bell shaped valve with the lever on the top. I was told to always fill the system with it open.

The expansion tank is on the back left side of the boiler in the last picture above. Here is a close up.
 
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Old 11-05-13, 04:08 PM
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I was told to always fill the system with it open.
Right... that's what it's for. If you tried to fill system without that it would take FOREVER! Why they call it a 'fast fill'.

You need to be careful with that though because in some cases you can easily get up to 30 PSI in the system and open the relief valve.

When purging system piping it's best to FIRST open the drain hose connection, and THEN open the fast fill.

When finished purging, FIRST close the fast fill, THEN close the drain.

With the lever down and the system in normal operation, you can lift the fast fill to manually 'bump' the pressure up a few PSI. Just keep an eye on the boiler pressure gauge so you don't feed too much.

That's what I was talking about when I wrote:

You can manually increase the pressure temporarily by lifting the fast fill handle on your pressure REDUCING valve (the fill valve) and adding a few more PSI. If you find this solves the problem we can talk about asjusting the pressure reducing valve so that it maintains that pressure automatically.
The expansion tank is on the back left side of the boiler in the last picture above. Here is a close up.
OK, good... Looks like a '60' size tank and that should be large enough to compensate for a slightly higher cold fill pressure... depending on what type of heat emitters are installed.

What do you have? Fin-tube baseboard? Cast iron baseboard? Cast iron radiators?

Read this post also, you can add a few optional bits to make servicing your expansion tank much easier! See graphic in the post... all you would need is 1 nipple, 1 tee, 1 hose bib.

There is a step by step procedure for properly charging the air in your tank which should be done at a MINIMUM of every two years because the tank WILL lose 1-2 PSI per year:

http://www.doityourself.com/forum/bo...sion-tank.html
 
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Old 11-05-13, 04:25 PM
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Cast iron baseboard at entry points, fin tube thoughout interior.

I came across that exact post about an hour ago researching the expansion tank.
I am sure it could use some servicing at this point but the
pressure seems ok, I never have seen any iota of water at the relief valve.

For the last 7 years this has been a simple task.
 
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Old 11-05-13, 04:35 PM
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Look on the boiler nameplate for the letters MAWP and there will be a number following the letters. Most common is 30 but in your particular case the number could be 50 or 60. Then look at the safety valve label and note what the set pressure is rated. The two numbers should match although it is possible the safety valve is lower.

The pressure REDUCING valve (make-up water regulator, automatic fill valve, etc) needs to be manually set to the minimum pressure for your system. The expansion tank air charge needs to be set the same as the reducing valve setting. The expansion tank air charge can only be checked or set when the tank is isolated from the system at zero pressure.
 
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Old 11-05-13, 04:38 PM
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I am sure it could use some servicing at this point but the
pressure seems ok, I never have seen any iota of water at the relief valve.
Right... but by now that tank is low on air, guaranteed. And when you bump up the system pressure to get the heat working on the top floor, you may be in for a surprise!

For the last 7 years this has been a simple task.
No reason for it to not continue to be so, but continue to neglect that tank and..................
 
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Old 11-05-13, 05:34 PM
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Ok I guess what I am missing is how to pump up the system pressure other than opening the reducing valve?
 
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Old 11-05-13, 06:20 PM
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Ok I guess what I am missing is how to pump up the system pressure other than opening the reducing valve?
The reducing valve is adjustable, and we'll get to that... but first, let's just bump it up a few psi manually and then see if we can get heat back upstairs. One step at a time. If my presumption is correct, you will get heat back on the 3rd floor and then we'll talk about how to adjust the reducing valve for a few more PSI.

If this DOES NOT work to get the heat back, there is still the possibility that you have air in the 3rd floor loop because of the time it has spent at SUB ATMOSPHERIC pressure... in other words at a slight vacuum. Yes, this can absolutely occur. What will happen is that the air in the fresh water you introduced to the system while purging will come out of solution and form new bubbles.

Remember that there is a TREMENDOUS amount of air dissolved in that fresh water and as soon as it is heated that air will come out of solution and form bubbles. ALL THE MORE SO in a slight vacuum.

So, you may have to repeat the purge on the 3rd floor loop and try again with the higher pressure.

Also, if you don't service the expansion tank, the likelihood of opening the relief valve is high...

Furd said: Then look at the safety valve label and note what the set pressure is rated.
Good advice from Furd... there is a metal tag on that valve. Tell us what it's rated at.
 
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Old 11-05-13, 06:47 PM
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Well, if nothing else I will shed the few pounds I have been meaning to going up and down the stairs.... (yes my sense of humor, though waning, is still in tact).

The MAWP value on the boiler is 50. The safety valve does not have a label on it but is stamped 30 PSI. I can post pictures tomorrow if necessary.

I have tried to purge the 3rd floor zone with the reducing valve open. It fills about a buckets worth of water and then stops. I've left it open for hours but nothing else comes through - not even a bubble. If I manually slide the motorized valve below the purge spigot water resumes coming out above through the spigot.

Does the air separator have any role in this?
 
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Old 11-05-13, 06:59 PM
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I have tried to purge the 3rd floor zone with the reducing valve open. It fills about a buckets worth of water and then stops. I've left it open for hours but nothing else comes through - not even a bubble.
If you leave that fast fill open for hours and don't see pressure increasing in boiler, and nothing is coming out the open drain valve, then something is wrong with the pressure reducing valve.

By all rights, with the fast fill open, and nothing coming out, within MINUTES or LESS your system should have pressurized to 30 PSI and your relief valve would be spewing.

What make model is the pressure reducing valve?

Just to make sure we're talking the same language, by 'opening' the fast fill valve, you are saying that you are operating a 'lever' or 'handle' on the valve, is that correct?

Can you take a close up of that valve?
 
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Old 11-06-13, 03:08 AM
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Here is a picture of the pressure reducing valve on the open position.

Here is another thing that doesn't make sense to me that I touched on before. If I isolate the zone by turning off the yellow handle fill valve AND the blue handle return valve, drain the zone until no water is coming out the purge spigot then even just flick the switch on the boiler on, water immediately pours out the purge spigot. If the zone is completely drained how could this happen? Could the return ball valve be bad allowing water to back through from the other zones/boiler? Could it bypass the motorized valve? None of the other zones behave this way.
 
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Old 11-06-13, 07:35 AM
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Here is a picture of the pressure reducing valve on the open position.
Mike, that valve may not actually be in the 'open' or 'fast fill' position with the handle all the way up.

What make/model is that valve?

When you lift that handle, the rounded part that is sticking out to the right side of the picture is supposed to act as a 'cam' that pushes down on a rod which goes through the center of the hollow threaded tube and in turn pushes on the diaphragm inside the valve in order to bypass.

By flipping it all the way over like that you may in fact be back to the same point as if the handle were in the down or closed position.

Try moving the handle such that the rounded end of the silver handle is straight up and down.

It's also possible that the 'rod' is missing from the valve. When you lift the handle, do you feel increasing resistance as if something is being pushed on? And then as you continue to push farther, does the resistance then decrease again?

If you unthread and remove that flip handle part, is there a rod inside the hollow threaded tube?
 
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Old 11-06-13, 07:50 AM
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From your first post:

A - I flip the switch on the boiler to the on position, water immediately begins to flow out the purge spigot
Because the pump turning on provides enough extra pressure to move the water through the loop.

B - with the boiler off, if I manually slide the motorized valve below the purge spigot to the left ,water also immediately begins flowing out the purge spigot above (that seems odd).
Because the water is coming up from below... GRAVITY and the pressure on the boiler is enough to force water back UP the pipe.

If I isolate the zone by turning off the yellow handle fill valve AND the blue handle return valve,
"Yellow handle fill valve" ? You mean one of the yellow ball valves on the supply header above the boiler? Why are you calling them 'fill valves' ? Those are simply 'isolation valves', nothing really to do with filling the system.

Are you absolutely certain that you know which one goes to which floor? perhaps the one you closed is not the one you think it is. Try repeating this with ALL of them closed.

The 'blue handle return valves' are the ones below the zone valves I presume?

If the zone is completely drained how could this happen?
Obviously the zone is not completely drained! When you drain a loop a 'suction', or 'vacuum' forms inside that loop. This suction is enough to hold water up in the loop. Same thing that happens when you put your finger on top of a drinking straw in a drink. Lift straw out, drink stays in straw.
 
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Old 11-06-13, 07:59 AM
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It is one of these Zurn Wilkens models - the tag is scratched so I am not sure exactly:

Zurn - Pressure Reducing Valves Zurn Wilkins Water Control

Oh, geez - you are 100% correct. I was essentially closing the valve again. THANK YOU!

What next? I think I know but I don't want to do anything out of order.
 
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Old 11-06-13, 08:15 AM
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Strange that none of the valves on that page appear to have the fast fill feature!

I would attempt to repurge the 3rd floor zone... make sure boiler is cool... leave yellow valves OPEN, close blue valve on return, hose on drain spigot, open spigot, lift fast fill on reducing valve to fast position, water should flow...

when all air out, release fast fill, close drain, allow boiler pressure to equalize and bump pressure up to 18 PSI...
 
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Old 11-06-13, 08:24 AM
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Ok yes, isolation valves - I call them fill valves because when I purge the air I open them to send water through the zone.

Ok, I get that water is coming back up through the system (I actually sort of figured that). However, if that blue handle ball valve is closed I believe that should not be able to happen. Isn't that the idea of being able to isolate the zone?

Yes I am 100% certain I know which valves go to what floor. They are out or order but identical on the front and back of the system

I just again want to thank you for all this. Really.
 
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Old 11-06-13, 08:30 AM
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Ok - the boiler has been off since 6 AM so off I go.
 
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Old 11-06-13, 08:51 AM
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I call them fill valves because when I purge the air I open them to send water through the zone.
But for the most part they are ALWAYS open, correct? Only time to close those would be for servicing the boiler and not having to drain the zones.

However, if that blue handle ball valve is closed I believe that should not be able to happen.
Ummmm... yeah... I missed that part originally I think. Right... how can water get past a closed ball valve? weird... can't explain!

Keep us posted!
 
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Old 11-06-13, 09:34 AM
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And...

WE HAVE HEAT! That valve MUST have had some sort of stop on it at some point. I couldn't have gotten lucky 7 years in row. THANK YOU! I am glad that I sent you the picture with it in what I thought was the "open" position.

Is it possible to add bleed valves at the top of the system? Or is this setup fine as long as the person knows when a valve is on?

As far as the yellow handles go, I always thought that in order to purge the air I had to close the zones and then go one by one, opening as I go across. So from this point on I should leave the boiler alone in the spring and just purge the air in the fall if necessary? No more draining except for repairs?

It is still running a little hot, isn't it?

So the list of things I have to check on (in the spring):

That blue valve to the top floor
. It is quite possibly broken. The yellow valves are all new. 2 out of 4 of them went bad so I changed them all. I've never seen ball valves wear out like that.

The expansion tank pressure
If you say it loses a 1 lb a year then it is definitely due.

The aquastat
If it is set at 180 and heating hotter, should I lower it a bit. Do some of these have a +/- dial which allows it to heat with a certain range? Or, if it is this inaccurate is it best to just replace it?

Anything else?

Thank you so much for all your time, patience and advice. I felt it was something sort of simple, that is why I turned to the forums instead of calling in somebody. I really learned so much. Mostly - leave it alone. Thanks!
 
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Old 11-06-13, 03:45 PM
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WE HAVE HEAT!
Hooray!

Does the air separator have any role in this?
I missed this question earlier on... but I don't see an air separator in the pics? Unless that's it in the 1st post, 3rd pic, the one with the wrench on top of the boiler... left center, trying to hide behind the electrical conduit?

Is it possible to add bleed valves at the top of the system? Or is this setup fine as long as the person knows when a valve is on?
Sure it's possible... MANUAL ONES! Do not even consider an 'automatic vent' at the top of the system. Whether or not it's worth the work is the question. Has it been a necessary ritual to purge and bleed this system every year?

You MIGHT find that by keeping the minimum pressure maintained a few PSI higher that your troubles with air 'go away' for the most part.

Having to manually purge air every season is a vicious circle... a Catch 22... because by the act of purging in order to push the air out, you are adding as much air, or more, BACK to the system in the form of all the dissolved air in the fresh water!

Additionally, the MINERALS in the fresh water you add each year cause scaling on the systems innards.

So... anything that you can do to your system which would reduce or eliminate the need to add huge amounts of fresh water each year would be a good thing. Good for the system, and less work for you!

As far as the yellow handles go, I always thought that in order to purge the air I had to close the zones and then go one by one, opening as I go across
You can do this... or not... Remember that water will always flow from HIGHER to LOWER pressure. Even if you leave all the yellow valves OPEN, the only one that the water will be able to travel through is the one with the open drain spigot! (because THAT is the LOWER pressure point).

I've been meaning to mention... it appears that the drain spigots are actually PURGE spigots, meaning that they have ANOTHER valve built into them. Look below the drain spout... see that screwdriver slot? That's a 'butterfly' valve built into the device. When that slot is parallel to the pipe, that valve is OPEN. When perpendicular to the pipe it's CLOSED. You have multiple ways to close the pipe and purge the system. Those butterfly valves, the zone valves, and the ball valves.

So from this point on I should leave the boiler alone in the spring and just purge the air in the fall if necessary? No more draining except for repairs?
Yes... that's what I would do... remember the dissolved air in the fresh water... and also the fact that 'corrosion' needs three things to occur.

WATER -- AIR -- FERROUS METALS

Take away any of those three and no more corrosion. Obviously you need the water and the ferrous metals... but you don't NEED or WANT the AIR!

After the system has been in operation for a period of time, the water heated to high temps to drive the air OUT of the water, that air VENTED FROM THE SYSTEM (your air scoop's job, OR manual bleeders on the piping) the water becomes INERT. No more corrosion.

So unless there is a clear REASON to drain and refill a system, in short, DON'T DO IT!

If you have continual problems with air gushing through the system, take steps to find out why, and correct those conditions.

more later...
 
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Old 11-06-13, 04:05 PM
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It is still running a little hot, isn't it?
Yes.

The aquastat If it is set at 180 and heating hotter, should I lower it a bit.
Yes. Lower it so the BURNER cuts off at the setpoint... like 180... be aware that you might be seeing 'heat soak'. When the burner cuts off on high limit, and the thermostat stops calling for heat at that point, there is still a lot of heat in the cast iron in the boiler that continues to transfer to the water. Now that the heat call has ended, and the pump stopped, the water in the boiler can go above the setpoint on the control. This is NORMAL and not a problem. So watch to see at what temperature the burner actually cuts off.

ALSO, the temperature inside a boiler is not the same at every point. There are hot spots and cooler spots. The point that the aquastat is sensing the temperature in the boiler may be COOLER than where the thermometer is measuring.

Do some of these have a +/- dial which allows it to heat with a certain range?
I'm not sure what you mean? Are you perhaps talking about a DIFFERENTIAL adjustment? All aquastats have a differential. Some are FIXED and some ADJUSTABLE. Differential prevents the burner from switching on/off/on/off/on/off when it reaches it's setpoint. The burners should switch off at setpoint and then when the water cools say 10F, if the heat call continues, the burners will fire again.

Or, if it is this inaccurate is it best to just replace it?
It's actually NOT a problem if it's inaccurate, just adjust to the temperature that you want the burner to cut off.

The PROBLEM comes if this setting is not REPEATABLE from cycle to cycle. If it cuts off one time at 180, and another at 190, and another at 170... THEN the control should be replaced.

The expansion tank pressure
Yes... often even MORE than 2 PSI per year. It is well worth installing that extra drain so you can easily do the maintenance on the tank without having to drain anything from the boiler. Add that valve and all you have to do each year is close the ball valve, hose on drain, let pressure off tank, leave drain open while checking or adding air, pump tank up to match your cold fill pressure (yours should go to 18 PSI to match), close drain, open ball valve. DONE!

The one thing you did not mention... PRESSURE GAUGE ... yours may be accurate, but I'm NEVER confident that gauges are, and when one trusts gauges, eventually they will not have any hair left.

ESPECIALLY because you have to run slightly higher pressure and closer to the relief valve opening pressure, you should KNOW that the gauge is accurate.

OK, that's enough for now... school is out.
 
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Old 11-07-13, 12:30 PM
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OK - that picture was taken right at when the boiler cutoff so 180 on the aquastat = about 220. It is consistently cutting off at that incorrect temperature.

Yes, I am talking about the +/-differential. Mine is a fixed one. I now understand how it functions.

I plan to add that drain to the expansion tank. It is simple enough. So if I just shut the boiler off and close the ball valve on the expansion tank I can go ahead and add it? Or should I wait until next fall?

I also plan on building the pressure gauge ASAP.

Unless that's it in the 1st post, 3rd pic, the one with the wrench on top of the boiler... left center, trying to hide behind the electrical conduit
Yes, that is is it.

Has it been a necessary ritual to purge and bleed this system every year?
In my religion of ignorance it has been! I also usually have to purge a bit of air out mid-winter. My guess now is that I have been actually doing the same thing with the fast-fill valve for years and because the system was newer, I might have just been getting lucky. I'm guessing this year there will be no need for a mid-season purge.

I'll re-purge the other three zones with the fast-fill actually open and see how it goes. Hopefully there will not be any need to even consider adding valves at the top.

That's a 'butterfly' valve built into the device
I was once told that those were installed to either speed up or slow down the flow of the water back to the boiler in order to achieve optimal Delta-T. It sounded good to me.

Well, thanks again for all the help. You should produce a bible about all this and offer it for sale. I would be first in line.
 
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Old 11-07-13, 01:18 PM
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If your hot pressure is bumping up close to 27 psi you can install a safety valve with a higher set pressure since your boiler has a maximum allowable pressure of 50 psi. I would use a 40 psi model.
 
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Old 11-07-13, 02:38 PM
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Good point Furd!

when the boiler cutoff so 180 on the aquastat = about 220. It is consistently cutting off at that incorrect temperature.
A 40 difference seems like a lot... it could also be caused by the sensing bulb not all the way inserted into the immersion well, and possibly a well that is a larger diameter than the bulb.

So roll it back to say 160 to start with and see how it goes, if the change is proportional.

So if I just shut the boiler off and close the ball valve on the expansion tank I can go ahead and add it? Or should I wait until next fall?
Yes... just close the ball valve... BUT, if you do that with pressure on the boiler water side, that pressure will still be in the tank after the valve is closed. When you unscrew the tank, the water in the tank (and there will be some!) will come out under pressure and spray all around.

So, close your manual fill valve and open a drain to let the pressure out first... only enough to drop to zero... in other words, DON'T 'drain' the boiler, just let the pressure off.

THEN go ahead and close the valve and remove the tank. There MAY still be some water in the tank so be prepared for it to be heavier than you might expect!

When you've got the new parts installed and the tank charged to 18 PSI, open the tank valve and open the manual fill valve. Boiler will let in a little water to make up for what was in the tank... and you're good to go.

You could wait if you want, but if you are going to recharge the tank, you will be dropping the pressure in the boiler ANYWAY to do so... might as well now.

Yes, that is is it.
What make (air removal device) is it? SpiroVent?

I'll re-purge the other three zones with the fast-fill actually open and see how it goes.
If you don't hear any air gushing around in the pipes, I would hold off on it.

I was once told that those were installed to either speed up or slow down the flow of the water back to the boiler in order to achieve optimal Delta-T. It sounded good to me.
One could attempt to do that. But would probably learn quickly that it really doesn't work that way. All you can do is SLOW the flow... and I'm guessing that there is no need to do that. I bet your delta T is already above 20. Slowing the flow would only make it greater. No... just leave them all wide open, you'll be fine.

Well, thanks again for all the help. You should produce a bible about all this and offer it for sale. I would be first in line.
You're welcome, you've been a great 'student'! Your name is at the top of my advance orders list!
 
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Old 11-07-13, 06:26 PM
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I double checked the temperature where the boiler cut off today and for whatever reason it was a bit lower - around 200. The aquastat was set for just above 180. 180 is the lowest setting possible so I moved the dial back until it was at the minimum temp. The boiler now seems to shut of around 185 (pressure approximately 22). I checked it twice and will look at it again tomorrow.

What make (air removal device) is it? SpiroVent?
Bell Gossett EASB-JR

EASB-JR Air Separator | Xylem Applied Water Systems - United States

I let you know how the expansion tank project goes - probably attempt it next week.
 

Last edited by NJT; 11-07-13 at 06:44 PM.
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Old 11-08-13, 06:31 AM
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Bell Gossett EASB-JR
And the cap on top is kept loose for air to vent?
 
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Old 11-08-13, 07:22 AM
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And the cap on top is kept loose for air to vent?
Yes. There is a slot in the cap that needs to be above the threads on the valve itself.
 
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Old 11-10-13, 07:18 AM
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And as a final installment -

All zones have heat. Running 18 PSI cold, 22 hot. Boiler is consistently shutting down at 185 degrees floating up to 210.

Picked up the parts to put the drain on the expansion tank. Hopefully will get to that by midweek.

Thank again.
 
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Old 11-10-13, 07:33 AM
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Excellent! Thanks for the follow-up.

I had this on my old system:



Initially had just the drain, wanted to add a gauge later so I made up that intermediate piece with provision for the gauge. You could do same with yours if you are looking for place to add a gauge.
 
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Old 01-02-14, 10:58 AM
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Air Seperator Issue

Hello NJTrooper - I'm back.

The system is functioning a-ok, probably better than it ever has thanks to all your help.

However, a few days ago a leak developed from the air removal device. It is coming from the threaded portion below the valve. I put a wrench on it and it is as tight as can be.

This is the brand, as mentioned previously:

EASB-JR Air Separator | Xylem Applied Water Systems - United States

I did my research on the forum and found a few threads regarding this issue (some that you have commented on). It seems that this isn't an unusual problem - these devices do corrode from the inside. I'm sure that I helped things along by flushing the system all those years.

It seems pretty straightforward to fix from what I have read. I can isolate the area and remove and replace the device without too much loss of water from the system. My question is, should I replace it with the same brand/model (seems like I can track it down) or is there a different brand that you would recommend? In past threads there seems to be a lot of mentions of Spirovent. Also, I see some models have a removable valve on top instead of a single unit. What would you suggest?

Thanks!

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