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Spirovent install

dpframing Member Posts: 25
I have a small Bunham boiler that's 8 years old and it is a one-zone system that heats up well. The problem is that it has no air elimination at all. No scoop valve, no air vent. When I purchased the house in 2003, the plumber showed me how to bleed the system from the boiler using the fast feed valve to boost the pressure and run water until I heard no more air bubbles or gurgling in the line. Of course this didn't work.

I want to install a Spirovent Jr. in the line and forget about bleeding once and for all. I need to know where to place it. I cannot put it near the expansion tank since the tank is installed at the end of the line right before the return. My hunch is that I can put the Spirovent in the line as it rises from the circulator pump. I have 3/4' pipe rising 3 ft.vertically from the pump, and then it makes a right angle for about a foot. In the picture, it is the section right above the duct.  Can I install the Spirovent there? They make a sweat model that doesn't even need brass fittings or couplings. Please check out the pics


  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    Confusing pictures.

    If I see that circulator correctly in picture .005, it is on the return to the boiler, so that is where the coldest water in the system will be. In other words, the worst place to put the Spirovent. You want it in the hottest part of the system. Furthermore, you want the circulator to be pumping away from the Point of No Pressure Change, which is at the input of the expansion tank.

    I do not know how much plumbing you want to do, but it seems to me you

    will need a Spirovent that mounts in a vertical pipe, such as a Spirovent Junior Series (Vertical) Air Eliminator: VJV75 They have pdf files on their web site, but they do not load correctly on my machine. I hope you have better luck reading them. And put it back there where the expansion tank connects. I cannot figure out the piping anyway. It looks as though the supply piping is stepped down a size and later back up, and that it then connects to the gas input to the boiler. It cannot be this way, but the pictures are very confusing to me.

  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    edited January 2012
    What WAS it connected to???

    Based on the pipe sizes shown in the pictures, it would appear that at one time the boilers were connected to large, standing cast iron radiators. If this is true, that type of heating system doesn't require any type of air elimination system or device. Any entrained air becomes trapped in the radiators and is manually bled from the radiators after filling. Any dissolved oxygen gets caught in the tops of the oversized radiators, where it doesn't cause any problems.

    If someone retrofitted baseboard where radiators once use to reside, THEY should have added a means of air separation/elimination to the system. In order for the system to be "ideal", starting from the boiler, and going through the system and back to the boiler, the components in the heating circuit should be as follows;

    Boiler (DUHhhh).

    Purge cock (drain cock same thing)

    Main supply isolation valve.

    Air elimination with expansion tank and make up water connected.

    System circulator.

    Circulator isolation valve(s)

    Heat emitters (fin tube or radiators)

    Zone valve(s)

    Common return back to boiler.

    Boiler isolation valve

    Boiler (AGAIN?!?).

    The way yours is set up, you should do Sawzall surgery and start from scratch. Adding a microbubble resorber on the supply is not going to correct the numerous problems your system already has from the original installation.

    Your pump is in the wrong place, your expansion tank is in the wrong place in relation to the pump, and both of these items are the root cause for most of your problems.

    Straighten out the mess, and you will NOT have to do ANYTHING else to the water side of your system. The gas side still requires annual inspections/maintenance, but the water side should be relatively maintenance free. WIll the system work as installed. Obviously, it will. But it will be fraught with a lot of issues, most of which you are experiencing.

    You see, hydronics are VERY forgiving. You can have a whole bunch of stuff in the wrong places, and it still puts out "heat".

    Heat is but one component of comfort, and once you straighten out all the components, you will get closer to discovering comfort. My personal definition of comfort is that you are not aware of your surroundings. Simply stated, you are "comfortable". You are not hearing bubbles in the system, you are not worried about the relief valve or operating pressure, and you are not hanging out on the internet trying to figure out whats wrong with your system. :-)

    Simply stated, you are COMFORTABLE, and you are not thinking about it.

    Good luck and Happy New Year.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • bill_105
    bill_105 Member Posts: 429

    And, the Bloody Mary will get you well on your way:)

    Our dog went nuts with all the fireworks, Happy everything!
  • dpframing
    dpframing Member Posts: 25
    edited January 2012

    This house was a gut renovation in 2003. That means EVERYTHING was torn out except the walls. The boilers are 8 year old Peerless. The black pipe , the copper pipe, everything is from 2003. I don't know where you're seeing parts of an old system.

    For every guy that says this is wrong, that is wrong, there's another pro who says this is ok , that is ok. The pump is in the right place. It came with the boiler and was factory installed in the right place. The maintenance brochure has it pictured right where it is. The only thing that might be right is the expansion tank is in a weird place but it still does its job.

    I am amazed how the pros can contradict each other. I just had 4 call backs to correct a problem on a trial and error basis. I had to repalce the relief valve, the fast fill valve, and the expansion tank. It was the tank the whole time. The other 2 valves were OK.  Now, in all honesty, I ask for some advice where to place a Spirovent, and I get all this rigamarole. If you were there in person checking out my system, you would say, "right here " in 2 seconds.

    And can somebody tell me why it costs $350 to install an expansion tank? A half-hour to bleed and refill the system, and 5 seconds to screw in the new part. That comes to about $700 an hour. Some of you guys are great, but some of you are worse than lawyers.

    I know I'm suppoed to be nice and not discuss pricing, but my experience with the pros was a bad one. I know you guys like Icesailor are on this site to help amateurs like me, but I had to vent. You guys know about venting, right?     
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    edited January 2012
    And can somebody tell me why it costs

    I am not a contractor, but I know what my contractor charges. He charges $xxx for each hour. Sometimes he sends a helper as well, for which he charges $xxx/2. One time he estimated two hours, but it turned out the job was easier that he thought, and the technician took 15 minutes to do the job. I was charged for one hour.

    But consider. There had to be a trained technician. There are training costs for him, salary, benefits, insurance. There had to be a truck that is paid for, filled with gasoline or diesel fuel, maintained, and insured, stocked with parts. The driver took 20 minutes to get here for which he gets paid. There was a clerk in the office who manages schedules, inventories, etc. She too gets salary, benefits. The office needs computers, heat, light, telephone and Internet service, insurance, property tax, business license and taxes, .... The owner deserves a salary if he does any work (he does at my contractor), as well as a reasonable return on his investment. All that has to come from somewhere.
  • icesailor
    icesailor Member Posts: 7,265
    Grumpy Install:

    I never told you to install a Spirovent or move your circulator. But you must expect some of us here to be mind readers. Your first posts were about no heat on the upper floors and how to properly purge your system. You didn't mention that the relief valve was dripping and you had a bucket under it. Because you didn't mention that, the question was answered about purging and how the fill valve was probably not filling properly. A reasonable assumption when there isn't enough pressure on the upper floor. But, water expands when heated and contracts when cooled. Contracting water means less pressure. No expansion tank means no place for expansion/comtraction to go.

    Not everyone here agrees on everything. I NEVER. EVER put fill valves on top of a boiler, feeding into the system like yours. I don't give a rats rosey red butt about any PONP. If I want the burner running while I test it, I put a hose on the systen/zone return and feed cold water into the boiler and hot water coming out of the return. That works for me.

    And the very first thing I check when I find a leaking pressure relief valve is to check the tank pre-charge pressure.  If it is zero or water comes out, it's time for a new tank.

    There's a group that I am familiar with. They have a saying. "Take what you need and leave the rest."  Sorry you didn't get what you needed. I get what I need. Maybe, you need an attitude adjustment.
  • dpframing
    dpframing Member Posts: 25
    yeah ok

    I posted 2 concerns the past 2 weeks as they arose. And I thank you for the free advice. The idiots that took 4 visits to solve my problem would have known the fix as you said, if they checked the tank. The tank had a residue puff of air in it with no water, so they said it wasn't the problem . But it was . It had no pressure. I replaced the Watts 15 with a genuine Extrol 30 and everything works fine now. No drip from the relief valve.

    Now I need a small question answered. Can anyone tell mewhere to put a Spirovent? My system has no air elimination. Can it be put above the pump as the picture shows?
  • icesailor
    icesailor Member Posts: 7,265

    If you had said that it was a Watts #15, some of us (at least I) would have said that it was shot. They have not proven to me to be stellar performers. I would have suggested that the Watts was too small. I would have recommended a #30 type/size.

    If the fill valve works, and you purge the system through the bottom, and fill the system with hot boiler water with the boiler running, and it starts to circulate, see if it keeps running.

    If you have series looped fin tube baseboard, you probably won't need to vent anything after you purge it. The house I live in that I built in 2000, may not have Jet Tees on the baseboard. I don't know. I've never had the covers off. I purge and leave it. All Taco #400 float vents have the caps screwed down tight in case they leak. If you think you need a Spirovent, put one on. I don't have one and the last one I put in, I capped it off because it vents air when I try to drain the systems by blowing it out with air.

    Not everyone has the same approach to things.
  • dpframing
    dpframing Member Posts: 25

    Got it . Thanks again.
  • hot_rod
    hot_rod Member Posts: 15,066
    edited January 2012
    a vertical separator

    would be the easiest to pipe into that system.

    Ideally you would want to pump away from the air purger with the pump on the supply and the expansion tank connected at that point. But if you are not up for that much change, a vertical sep just below the low water cutoff switch would work fine. The expansion tank is tied into the boiler, pump on the return, so air will be eliminated best at the hottest point, that being the supply.

    While not exactly your case, this article might be a good read.

    Under the Resources button on top, click on Dan' Stories, then look for this parable.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • icesailor
    icesailor Member Posts: 7,265

    And those guys, the "experts" will say I'm full of it and I don't know what I am talking about. But you needed a new tank.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837

    I get the impression that you either don't understand the PONPC, or you don't believe it exists. No?

    You've intimated that it makes no difference as it pertains to pump location. In all of my years of teaching, the concept of the PONPC is without a doubt one of the hardest concepts for my students (and people in general) to understand.

    It is real. It is also key to trouble free "system" performance. You obviously have a real good grasp on static water pressures based on previous posts. Let me try and explain what I have "seen", and proven time and time again as it pertains to the PONPC, pumps etc. This is not meant to demean anyone. It is intended to educate, not only yourself, but others who may have a problem seeing this concept in their minds eye.

    As most people who work with water know, in order to raise water vertically through a pipe/building, we MUST have a minimum of 1/2 PSI (actually .434 PSI) of pressure to raise the water one vertical foot. To this, it is recommended that 5 additional PSI be added to insure that there is residual positive pressure at the top of the system to aid in purging the air out of manual vents, and to avoid hotter water possibly seeing a negative pressure, which would cause the 180 degree F water to flash to steam... Enough about static pressure. Lets move on to the "pressure differential" machines, also known as pumps or circulators. Let me quickly explain the difference between a true pump and a circulator. A pump, say a submersible pump for example, HAS to "lift" water vertically in elevation in order to overcome the atmospheric pressure. It is physically lifting water vertically, from the bottom of the well to the dwelling, and MUST generate enough residual "pressure" to provide flow of water.

    A circulator, on the other hand, is NOT designed to "lift" water vertically, although they do have that capacity, limited as it is. A circulator in a true closed loop system is strictly creating a pressure differential between its inlet and outlet flange. This is where Dan's picture of a ferris wheel comes into play. Once the Ferris wheel is full of people, and moving around in a circle, the weight of the people going down, is countering the weight of the people going up. The same concept applies to moving water. In a filled, closed loop system, the weight of the rising water is equally countered by the water falling. Very little energy required to achieve movement. Now for some clarification. Over the years, the trades have used both terms (pumps and circulators) as one to the point that it can cause confusion.

    Back to the pressure differential machine. If your static fill is say 12 PSI, and you chose a circulator with the capacity of generate 10 feet of head, and you installed this circulator with the expansion tank connection (PONPC) as close to the pumps (circulator) inlet as is possible, the pump will ADD its pressure differential to the static fill pressure, so the pressure at the outlet of the pump when on would be approximately 17 PSI. The 5 PSI that the pump added to the system is what causes movement, because EVERY pound of pressure that it generated will be completely consumed by pipe friction by the time the water makes it back around to the pump for anther ride. It has to, because if there were ANY residual pressure, the SYSTEM pressure would increase with each pass until the pressure relief valve did its thing.

    Your explanation of a deep well jet pump is incorrect. A jet pump is nothing more than a high velocity (GPM) pump that moves water through a venturi device (foot valve with internal check valve) , which SUCKS water into the circulating loop, which causes an increase in water volume within the pump loop, which creates pressure. In that case, with each pass of water around the loop, additional water IS induced into the circuit, causing a subsequent increase in pressure, which is typically stored in a pressure tank until needed.

    SImilar to a circulator, with the exception of the venturi and foot valve.

    Now, lets move on to the PONPC. I too struggled with this concept, until one of my scorched air students woke me up. It was one of the first classes of the year, and I was telling the students about the benefits of hydronic heating, and I told them that even Mother Nature was a fan of hydronics because she had covered more than 75 of the worlds face with water. This scorched error student in the back said "Yeah, and she covered the world 100% with air..." Got my attention.

    So, back to basics. If we do have a submersible pump in a well, what is the ever looming, overwhelming thing that we are trying to over come? It's atmospheric air pressure. What Gil Carlson established and called the Point of No Pressure Change, and I shortened to the PONPC :-)

    In an old open gravity system, the PONPC is the expansion tank in the attic. In a gravity fed potable water system, it is the reservoir that is holding the water. In a closed loop heating system, it is that point in the system where the "atmosphere" has an influence on the fluid within the system, which is where the expansion tank (bladder, or non) makes its connection to the system. As the name implies, in a closed loop system, the circulator can NOT influence the pressure at the PONPC. A circulator can only add or subtract its pressure differential to the systems static fill pressure. Hence, if it is pumping away from the PONPC, it will ADD its pressure differential potential to the static fill. If it is pumping towards the PONPC, it will SUBTRACT its pressure differential from the static fill. It is this subtraction that takes us to the next problem, that being gas in suspension in the water. This is where Dan's soda bottle comes in. Under pressure, you can not see any of the bubbles in suspension. Relieve that pressure and a GAZILLION gas bubbles come out of no where. The same ting happens in a closed loop system. If the water sees a negative pressure, a GAZILLION micro bubbles come out of suspension, and can accumulate in high places, causing air binding. If the pump is pump away from the PONPC, all pressure is kept high, keeping the air in suspension on the water, and sweeping them to a safer place for removal, preferably a place where the residual pump pressure is low, and the operating temperature is high, and the velocity of the fluid is low. This is where air is most likely to come out of suspension.

    The bottom line is this and it is based on my 35+ years of experience. Once the system has been properly purged, if you will set ALL circulators so that they pump away from the PONPC, air in suspension noises, and air binding issues, and air related problems in general will be no more. Guaranteed!

    As you said, take what you want, and leave the rest. But I GUARANTEE you or anyone else reading this that if you follow my recommendations, you will NOT have any further air in suspension problems.

    To dpframing, the reason I thought it was an older system was due to the use of the black iron pipe. My bad. You can stick the MBR wherever you want, because unless it is piped within the circuit, it will not do you a lot of good. You came here seeking information. It was given to you freely, and you dispute it. You are looking for a velcro fix because you obviously are intimidated by the skilled piping professional and their ability to make piping changes that you can't. As for cost, you again obviously have no idea what it costs to be in business, and think that everyone should charge what yo do per hour for your services. How many years of schooling were you required to go through before you were turned loose with a hammer and nails? Me? 5 years minimum. And I am still learning everyday.

    The contractor was probably using a "flat Rate" estimating book, which assumes no working isolation valves (worst case scenario estimating) and your system HAD the isolation valves required, hence the tech was in and out in short order. In the long run, they probably lose more time and money on other systems that do not have the isolation valves that yours does, hence the reason for the pricing.

    As for the manufacturer shipping the pump on the return, they do it from a convenience point in shipping. Just because it came there does not mean that it is in the ideal spot. Its not. And if you ask them, they will admit that it would work better in other places. WIll it work there, obviously it will, but you CAN expect to have air binding issues (which you have) and air in suspension noise issues (which you also have or you wouldn't be here wasting our time...).

    If you had invited me into your boiler room, and I had seen everything first hand, my recommendations would still be the same. You can keep dinking around, or you can address all problems and be doe with it. Your money, your call.

    Personally, I think you owe the pipe trades an apology, but again, its your call.

    Respectfully, to all who took the time to read this, keep learning. And please pay it forward.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • icesailor
    icesailor Member Posts: 7,265
    Replies: PONC


    I'll need to make multiple replies. My aged brain can't keep that much stored away in memory anymore. I have a shortage of active RAM.

    I understand PONC. In my opinion, there are actually two PONC's. One in the volute of the pump and the other 180 degrees or half way +/- around the system. In a gravity heat system, there are still two, One at the attic tank, the other in the boiler, somewhere around half way up. System pressure is the only pressure that stays the same. Pumping or flow pressure that the pump adds is not the same. It's most useful addition is giving the ability to tell how much the pump is pumping through the system by the differential pressure. If a Wilo Star 21 is pumping into a 4" gravity system with radiators, and shows no rise in differential pressure when the pump starts, the pump is pumping 20+GPM. If however, the same pump is pumping into a smaller loop, and the differential pressure, the outlet and return pressure going into the pump, is 6#, it is pushing a 13.86' of head pressure. Therefore, the pump is moving 10 GPM +/- through the system. The difference is resistance. Pumps develop a finite amount of energy. They have two ways to use it. Suction and pressure. If they don't need to use any energy to make suction, they can use all their energy to make pressure and volume. The higher the suction lift needed, the less there is for volume. The impellor in a single stage well pump cam practically deliver 50# pressure. But the volume goes down as the suction goes up. It only has the finite energy to do one job. If you add a second impellor or a second stage, the pressure goes up but the amount of water goes down because the first stage can not deliver more water than it is designed to. It also can't double the pressure.

    Well Pumps:

    Jet pumps or ejector pumps don't "lift" water. They pump water through the "jet" and create a vacuum to have Mother Nature "push" the water up the pipe. Again, the greater the lift, the lower the volume. The pressure stays the same. That's when the Ejector is mounted on the pump. But you can use a "convertible" pump and put the ejector in an open well with the supply and return pipe connected to the ejector and the pump. circulating water through the nozzle and venturi. For every 4 gallons that floe through the nozzle, 5 gallons flow through the venturi tube and up the supply pipe where pump suction helps it along. If the pumping suction is low, more water comes out the pump head. If the suction pressure is high, less water comes out the head.

    If the static water level in the well is 40' below the pump head, the pump pressure going down the "down" pipe will need to be high enough in PSIG to "push" the water through the nozzle and venturi, to a level where the pump can then "suck" the water up the rest of the way. The adjustment is made with the pressure regulator adjustment screw on the regulator head.

    Here's a cool thing about deep well ejector pumps. If you put a 35' tailpiece on the ejector, and put it into a 4 GPM well, the pump and ejector will adjust itself to the inflow of the well and as the vacuum/lift goes up, the GPM goes down.

    This is the opposite of submersible pumps. Submersible pumps do absolutely no "lifting" or develop suction. All and every unit of energy they provide, goes to making pressure. The same 50# that the ejector pump has. But, you can buy multi-stage jet pumps and they will do the same thing. Increase the discharge pressure. But submersible pumps do it better. You can pack a whole tribe of impellors or "Stages" on a shaft and spin it with a motor. If you want 20 GPM. delivery, you must get a pump with a large enough HP to generate the pressure to push the water up the pipe and get it to the surface with enough pressure left over to give you the house pressure that you want. There's no "sucking"

    Back in the days of my experience with Jet Pumps, the biggest service complaint was where the copper tube that went to the pressure switch connected to the CI pressure head, would cover over with iron deposits. The pump would go up as high as it was capable of pumping and not shut off, The friction of the impellor in the water and the suction/vacuum developed in the impellor would make steam and air in the pump volute. The pump wouldn't pump any water. Take the plug out of the top of the pump,start it and water would squirt up a couple of feet and start pumping. Excessive resistance in a hydronic heat system does the same thing.

    Oh yeah, a piece of rust debris, stuck in the jet and slowing the flow of water through the venturi will absolutely change the ability of the pump to deliver pressure. It may deliver lots of water but it won't be at a very high pressure. 
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837

    I gave it my best shot. Unless you have two expansion tanks in any given system, there is only ONE point of no pressure change. I didn't make this stuff up. People a lot smarter than I established this long before I even got interested in working with hot water heating.

    Maybe we both mean the same thing, but you are just stating it differently.

    Or not.

    Safe travels.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • icesailor
    icesailor Member Posts: 7,265


    You used the example from Dan about the Ferris wheel. If the Ferris wheel were a clock, there would be equal pressure at 3 O'clock and 9 O'clock. Somewhere in the system, there is another place that with the pump pumping, the pumping pressure will be equal to the static system pressure.

    The fill valve should always have static or positive pressure pushing on it. If the fill valve "sees" less than static system pressure, it will add water.

    I'm not arguing with Gil Carlson.
  • Mike Kusiak_2
    Mike Kusiak_2 Member Posts: 604
    edited January 2012
    Expansion tank and PONPC

    Mark, perhaps this attachment will help get your point across. Dan provided it when I had questions regarding pressure changes in a closed system when the pump starts. I think it comes from B&G, where the concept of PONPC originated. It gives excellent visual representations of the pressure gradients that occur pumping towards and away from the tank.

    Note: the attached PDF has the pages reversed, so read page 2 first.

    I think I understand what Ice is thinking. He is visualizing the pressure differentials as they would occur in a sealed system without the influence of an expansion tank. With no tank, the pump head differential would be split equally at the inlet and outlet of the pump, so in that case there would be two PONPC's. One in the center of the pump and one at the halfway point of the system piping.

     But the tank fundamentally changes the situation. Since volume and therefore the pressure of the tank can't change, connecting it to either the inlet or outlet of the pump will force the entire pump differential to add or subtract from the static system pressure. With the tank added,  there will only be one PONPC occurring at the point where it is connected to the system, rather than the two that can occur without it.
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    edited January 2012
    Great find Mike...

    Thanks as usual.

    Siggy uses the same graphic in his book. I actually had to develop a visual demonstrator for a case law trial, and when the defense found out what I had built, and how it worked, they dropped their contention that the pumps location in respect to the expansion tank made NO difference. It was REAL graphic, with 6" gages, a pump before and after the expansion tank, and air scoop, and a clear plastic tube to show what happens to air in suspension. It hangs on the wall at Red Rocks Community College plumbing shop now.

    I too agree about a loop without an expansion tank, like the geothermal people have been doing for years, and all of the air binding issues I've had to address from THOSE gems over the years. For the minor costs of an air eliminator and a small expansion tank, their systems COULD work SO much better. You;d think they;d learn from our mistakes :-)

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • bill_105
    bill_105 Member Posts: 429
    Before term PONPC

    I think this where I saw a publication from the 30's concerning tank location. Perhaps it was B&G's but think it was HH's. A trade group was dealing with this new circulator thing and it said "usually on the return". I can't find it.

    I'm glad I'm not the only one who struggled with this at the beginning. It's so simple now. The pump can't give or take water from the tank! That's it, that's the whole thing.

    Man, that poor guy who started this thing, talk about being thrown to the lions:)!
This discussion has been closed.