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Vibrating Munchkin boiler???

I have a Munchkin t80m boiler w/ a 925 controller. I recently installed this boiler in my home. At a uncertain stage of operation the boiler vibrates uncontrollably followed by a burp sound. How do I fix this problem???
SUPER SERVICE WITH A SMILE!
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Comments

  • edited November 2010
    More details,,,,

    How did you size this Munchkin for your needs????

    They are a good boiler.
    Post edited by Unknown User on
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    Its for a small 3 zone radiant system w/ a 36 gal. hot water maker. I piped it up as per Munchkin Spec Drawing 2D in the installation guide. Except I have mixing valves between the supply and return before my pumps.
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    edited November 2010
    Vibrating

    You either have a hydraulic problem or you have a combustion problem. It's doubtful that there is a control issue, though it is possible. I know that's a general answer but  your info is very vague.



    I would lean towards a combustion problem. What gas? L.P. or natural? What is your incoming gas pressure? What are the numbers from your combustion analysis? Particularly co2 and o2. How long is your vent run and how may ells in it? Is it properly graded @ 1/4 per ft. back to the boiler? Where and how does it terminate?



    From the hydraulic side, you could be making steam from air in the system or insufficient flow.



    Please post some pics of the near boiler piping and the vent piping or a diagram of your piping.
    Post edited by Ironman on
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    I heard I need to calibrate the gas valve? Yet, I was told I can only do this w/ a CO meter. HELLLLLP!
    SUPER SERVICE WITH A SMILE!
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    Gas Pressure and Co2...

    Can only be checked with the proper (and expensive) equipment. This is one reason that only a pro should be selling and installing this equipment. I would suggest you check the "Find a Contractor" tab above. You need a pro.
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    edited November 2010
    Munchkin

    I'm from NJ where my nat gas pressure is around 2 lbs.I vented it w/ 2" pvc pipe w/ 2 ells on intake and 2 ells on exhaust. The linear run of each is approximately 21" w/ pitch towards boiler. I dont have a CO meter to measure O2 and CO2 levels.
    Post edited by SUPER DAN P&H on
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  • icesailoricesailor Posts: 6,807Member ✭✭✭
    Vibrating Munchkin

    What does that mean. You have a restriction in the primary loop? That will slow down the flow through the boiler? In my opinion, you shouldn't have ANY restrictions in the primary loop that can allow the water to flow slow wnough to flash into steam. It will do it in a heartbeat. These are really tough little boilers. They got a really bad rap because installers didn't read the instructions and piped them wrong. Then, they blamed the boiler for their mistakes.

    Is it LP or Nat. Gas. It makes a difference. It must be set up properly by someone who knows what they are doing with them.  I don't consider myself one of those.
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  • icesailoricesailor Posts: 6,807Member ✭✭✭
    Gas Pressure"

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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    Pic of my boiler
    JPG
    JPG
    Munchkin boiler 001.JPG
    0B
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    Where You live...

    Has nothing to do with the gas pressure on the inlet of the boiler. It needs to be measured with an accurate manometer. If it is actually 2psi at the boiler, then you  need a regulator to step it down, but it still must be set with a manometer. This is critical. Then the fuel to air ratio must be set with a combustion analyzer. These things cannot be done by guessing or generalizations.



    Again, you may have flow issues.



    Please post some pics or a piping diagram.
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
    · ·
  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    Pic posted. I piped as per Spec 2D in the installers manual.
    SUPER SERVICE WITH A SMILE!
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    Very nice workmanship

    But if I'm viewing your pic correctly, your piping is wrong. It appears that you don't have primary/secondary piping or a primary pump. This means that you're not getting sufficient flow through the boiler which could be your problem. When the mixing valve(s) begin to bypass, you loose flow through the boiler.



    Please post another pic or two from a different angle so that I can confirm that I'm seeing this right. Also one showing the pipes going into the boiler.
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    Behind the expanion tank is a Taco 007 pump. Its piped primary/secondary w/ the tee's next to each other.
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    edited November 2010
    Not Piped According to Diagram 2D

    Take a closer look at the diagram. The valves in Munchkin's diagram are flow checks installed after the zone circs., not mixing valves before the circs. When the mixing valve(s) bypass, you're not taking any heat from the boiler and flow stops in the primary loop.
    Post edited by Ironman on
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    I have flow check circ flanges after each circ. The mixing valves are for a radiant system. I installed my mixing valves as per my suppliers directions.
    SUPER SERVICE WITH A SMILE!
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  • Charlie from wmassCharlie from wmass Posts: 2,966Member ✭✭✭
    When did those unions get rated for flue gas?

    I thought they were for inlet air and water use only. Also are they pressure fittings? the radius is kind of tight for air flow. The vibrating is a clear indication you need to get a professional in and do a combustion test. Also the 007 may be too small for the boiler's required flow rates.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Munchkin

    They're full port unions for cleaning. They are pressure fittings w/ about 24" linear run each. Theres a 12" gap from exterior.
    SUPER SERVICE WITH A SMILE!
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    also

    the 007 pump is fine by specs.
    SUPER SERVICE WITH A SMILE!
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    Mixing Valves

    Are stopping flow in your primary loop when they bypass. Your supplier was wrong for this piping arrangement. Munchkn's 2D diagram is for a high temp loop, not low temp radiant. You should be piped like 4A with the vision1 and a high limit.



    Are you trying to maintain the same temp in all the loops? If so, then turn the temp on the mixing valves all the way up and set the heating control on the boiler to about 80 - 85 deg. and let the boiler maintain the water temp in the loops. The boiler will stay in condensing and be much more efficient that way.



    You would still need to address your gas and combustion issues.
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
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  • Charlie from wmassCharlie from wmass Posts: 2,966Member ✭✭✭
    I was concerned about the gasket material in the union.

    The only PVC unions I have available have an O-ring gasket. I do not know if this is what you have. I like the union idea but I would not use them on the exhaust. The piping is nice and neat. I do think you need a combustion analysis.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
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  • Charlie from wmassCharlie from wmass Posts: 2,966Member ✭✭✭
    Did it meet specs

    for the 007 when the check valves are figured in?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
    · ·
  • Charlie from wmassCharlie from wmass Posts: 2,966Member ✭✭✭
    You did use 1 1/4" for the boiler piping?

    Where is the circ for the indirect tank?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
    https://heatinghelp.com/find-a-contractor/detail/charles-garrity-plumbing-and-heating
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Thanks Charlie

    They do have a o-ring. I sealed them w/ a hi temp grease to protect them. Do you think my piping is incorrect for a radiant heating system? can you suggest a meter I can purchase for a low cost yet effective?
    SUPER SERVICE WITH A SMILE!
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  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    good question

    it does for the heating. yet i got one for the primary too. not on my spec sheet. do you think thats a problem?
    SUPER SERVICE WITH A SMILE!
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  • HenryHenry Posts: 470Member ✭✭
    Install

    PVC sch 40 unions usualy have viton O rings. These are NOT suitable for any petroleum based substance including natural gas. Buna N is required for instances of pretroleum based contact. The fact that you put grease on them is actual worse. They will at one point start to bloat and detereoate!



    Standard pumping installation require 5 dia before and 3 dia after any pump. This does not apply is you use  suction diffusers as in thelarge comercial jobs that we do. In our install we have standardised at 5  dia on either side. With all those elbows and the mixing valves you have a lot of turbulance and loss of flow. With the loss of flow, your boiler cannot desipate suficiently and is making steam, thus vibrating.

    Seen this many times before! We repipe the install to proper piping standards and sometimes have to resize the pumps.

    These Ginonnani heat exhanger do not all have the same flow restriction (head). Every so often, we get a two boiler setup with the same number of elbows and lenght of pipe but one boiler will only fire up to 80%. We replace that boiler's pump with one with more head to solve the problem.



    While it looks neat, you do need a pro and combustion test. Please chuck the unions! It woiuld not pass inspection in Canada.



    Henry
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  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    Where is the circ for the indirect tank?

    I believe it is the one to the left of the Indirect Tank, just higher than the top of the tank.



    For the W-M indirects, the hot water coming in from the boiler goes into the bottom of the tank. Those pipes should be 1" for W-M boilers putting out up to around 105,000 BTU/hr, 1 1/4" up to 155,000,  and 1 1/2 above that. And use Taco 007, 010, 012, 014,  and 013, depending on the boiler and tank size.



    My table assumes a W-M boiler, so may not apply to a Munchkin.



    W-M recommend 190F water going into the tank; I happen to use 170F because my hot water demand is low (one-person, not a teenage girl), and I can tolerate a little slower recovery rate. But at that temperature, I have seen fit to insulate the pipes to and from the indirect with 1/2" thick black foam.



    It looks strange to have the makeup water entering the system at the hot water intake to the indirect's outer tank. But I guess it does not matter because not much water should enter the system after the Spirovent gets all the air out.
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  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    Gas pressure?

    I am from New Jersey as well (NJNG) and when my church had heating problems (heat exchanger clogged with soot, for one thing), the gas company came out and tested some things. In particular, the gas pressure was wrong, so they replaced the regulator. They then set the pressure to 7" with a water manometer. I cannot remember if this was with the furnaces running or not.



    I live two blocks from there and I know the pressure down the main in my small street is about 15 psi, so I assume the regulator by my house (at input to gas meter) takes the pressure down to 7" as well.



    For my boiler (W-M Ultra) the I&M manual says 13" maximum with no flow, and 5" minimum with gas flowing at high fire. Since water gauge pressure is 0.434 psi/foot, 12" pressure is a bit less than 1/2 psi. If yours is 2 psi, something needs to be done. My boiler does not have a pressure regulator in it, unless you think its gas valve has a regulator hidden in it.
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  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    trying to maintain the same temp in all the loops?

    I assume not. He needs relatively low temperatures in the heating loops, and relatively high temperature in the indirect water heating loops.



    In some mod|con boilers, the boiler can put out (at least) one temperature for heating loops, and another temperature for an indirect heating loop. The way the piping is done here, the controller would need to make sure the heating circulators are off when firing at high temperatures for the indirect. And you would want the indirect circulator off when running any of the heating circulators. It is not clear that the controller of the Munchkin can do that (I am not saying it cannot); I got the impression that the Munchkin could be set to run at any one temperature desired (within a reasonable range). Also, we know nothing about the controls connecting the various thermostats, aquastat, and circulators in this system.
    · ·
  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    O-Rings

    I am not a professional, and do not know the code for these. I do know that petroleum grease is very bad for rubber items, so I hope if your code permits that you used an appropriate silicone grease.
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  • icesailoricesailor Posts: 6,807Member ✭✭✭
    Munchkin Wiring:

    First of all, this install looks like the demo install of a trailer used to demonstrate Munchkins and how they work. With all that aluminum diamond plate on the wall. Nice though.

    Second, aren't there two circulator leads in the munchkin? The first one is for heat and the boiler comes on at low fire, slowy ramping up. And the second one is for the indirect where it comes on at high fire so it starts heating water immediately and there is no restriction because the water heater indirect is actually part of the primary circuit?  Something about that concept bothers me but they're smart and I'm not.

    I found this out when an electrician winged it on a wire up and I had to figure it out.

    And I agree with everyone here that the mixer valves are causing too much restriction in the promary loop. Had it been done with "bridge loops", it would have worked. But not with a restriction on the crossovers.

    Set the mixers for maximum hot, then on all three and if the problem goes away, that's the problem.

    You guys here sure know your poop. It's a joy to read this stuff.
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  • Mark EathertonMark Eatherton Posts: 4,803Member ✭✭✭
    edited November 2010
    Get rid of the union on the exhaust....

    When plastic goes through expansion and contraction, the unions will eventually loosen themselves, and then you will have products of combustion getting into the living space.



    Watch the pressure gage as it is going though its stages. If you see the pressure bouncing at the same time the appliance is vibrating, then it is most probably a flow issue. Could be air in the system too. Those Gianonni heat exchangers are tough to purge.



    Watch flame signal strength when it is going though its paces, and if you see a deviation in voltage, it could be a fire side issue.



    Also, I don't see any purple primer on your PVC joints. I hope to God that you didn't assemble the joints without using the required primer. This is how people die (Aspen Colorado).



    Seriously.



    ME
    Post edited by Mark Eatherton on
    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.
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  • SlimpickinsSlimpickins Posts: 309Member
    edited November 2010
    purge valves?

    From what I can make out, you don't have a true primary/secondary arrangement on the piping. It's hard to see in the upper left hand corner but you have elbows too close to your closely placed tees. Is the primary pump hidden by the expansion tank? I don't see any purge valves either, might have air in the system causing vibration. Not crazy about how you did the make up water tie in on the DHW loops. Most likely you have a flow problem and need to get that combustion set up. as well. The unions are a bad idea and illegal too, I know of no manufacturers or codes that specify unions.
    Post edited by Slimpickins on
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  • icesailoricesailor Posts: 6,807Member ✭✭✭
    Unions/exhaust:

    Munchkin uses a "fernco" type coupling on the exhaust. Why not use one of those on both the intake and exhaust? You will play hell unscrewing those unions in a year or so. You will probably break the nut.

    Mark E.,

    I NEVER, never ever cement PVC without deburring the pipe and cleaning the inside of the fitting and the outside of the pipe. I only use clear cleaner because I think that although there is no question that you have cleaned the pipe and fitting when you use it, I always wipe the cleaner off with a clean white rag. I think it looks tacky and unprofessional. You can always tell I cleaned the pipe though because you will see the MFG's painted stripe removed where I clean it. I also find that the purple stuff doesn't do a very good job of cleaning the pipe because it has always dried before I cal wipe the rag on it.

    Is there some foolish requirement that I an doing it wrong?

    Just asking.
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  • SlimpickinsSlimpickins Posts: 309Member
    another question

    Why didn't you get the Vision 1 control? it would have save a ton of work and materials like mixing valves.



    And about Icesailors reply to ME, I've worked in several jurisdictions in Colorado and they all require purple primer on venting and all PVC waste and vent plumbing.
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  • Mark EathertonMark Eatherton Posts: 4,803Member ✭✭✭
    Witness Dye...

    Ice, The die is colored for the benefit of the inspectors. It allows them to visually see that primer was used. I hear you about craftsmanship, but some DIYer's don't know what you know and probably will not use primer period, which leads to joint failure due to thermal expansion and contraction. To be quite honest, I didn't think you could get primer without coloration in it. I can't here in Denver, and wouldn't anyway. As for the primer drying, that is fine. It isn't intended to soften the pipe, although it does superficially. It is meant to remove any surface contaminants (oil, skin oil etc) to insure a good clean bonding surface. The actual placement of the glue causes a small chemical reaction that generates a small amount of heat. If you don't hold the joint firmly together for about 30 seconds, the reaction will actually push the pipe out of the fitting, I know I am preaching to the choir here, but you must remember who it is that is reading this information, and their level of skill compared to yours and mine,,,,



    It is also important to chamfer the leading edge of the pipe to keep it from acting like a piston and pushing the cement out of the joint during insertion. All of this information is on the can of glue and primer, but who bothers to read that crap?



    I do. Even if I've used it 1,000,000 times, I take the time to read the instructions at least once a year, to see if anything has changed, and it does.



    You are a recent joiner/poster here at the Wall. If you don't mind, tell us about yourself, your years of experience, locations worked etc. I like to know where people stand before I find out where they sit. :-)



    Welcome to the Wall. I enjoy reading a good response.



    ME
    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.
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  • IronmanIronman Posts: 2,108Member ✭✭✭
    Radiant Loops and Vision1 Controls

    JDB,



    I was referring to the radiant loops. Obviously, the indirect needs high temp.



    The mixing valves should not have been used in this application. When they reach their set point, they begin to bypass all the flow into the radiant loop and flow ceases in the primary loop. When this happens, the only flow through the boiler that's taking place is what's in its own loop going actually in reverse through the closely spaced tees. Since the volume of water in the boiler and its loop is so small and the heat transfer so rapid, It can flash to steam and cause the kind of problem this poster is experiencing



    Had he used the Vision 1 controls and piped the indirect off the boiler loop as the instructions show, the boiler could maintain the low temp needed in the radiant loops and high temp to the indirect when it calls.
    pdf
    pdf
    MunchkinRevision2Installation.pdf
    0B
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
    · ·
  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    Obviously, the indirect needs high temp.

    About those mixing valves (that I agree should not be there), I do not think they affect the flow rate in the primary loop at all. It is true that they could affect the temperature of what flows in the primary loop though.



    If I understand the picture, it is true primary-secondary, with the circulator of the primary loop hidden behind the expansion tank, and the closely-spaced Ts just to the left of it.



    Now if the mixing valves go into bypass mode, it is little different than if the circulators in the secondary loop turn off. The significant difference is that whatever shuts off those circulators would presumably also stop the firing of the boiler. The main idea of primary-secondary piping, if I understand it correctly, is precisely to make the flow rate in the two circuits independent. So if those mixer valves bypass everything, the water temperature entering the return of the primary loop would rise very quickly, and I would hope the control of the boiler would reduce the firing rate appropriately (in this case, to zero, I suppose).



    I know with my W-M Ultra 3, the control notices if the temperature increase in the primary loop exceeds 2F per second and, if so, shuts the thing down. It also shuts down if the temperature in the primary loop exceeds 200F. I do not know the controls of a Munchkin, but I suppose it has something like that to protect its heat exchanger.
    · ·
  • IronmanIronman Posts: 2,108Member ✭✭✭
    Flow Rate

    JDB,

    You're confusing primary/secondary series piping with primary/secondary parallel piping. In this situation, the poster has (correctly) piped the system in primary/secondary parallel and the secondary circulators are what cause flow in the primary loop. There is no pump in the primary loop. Therefore, when the mixing valve bypasses the primary loop, there is no flow in the primary loop.



    I believe you are confusing the boiler circulator for a primary circ. The boiler loop is a secondary series loop off of the primary. The boiler circ. does not induce flow in the primary except between the closely spaced Tees. Again, there is no primary loop circ. in this arrangement, therefore, the secondary parallel circs. induce flow in the primary. That's why the mixing valves are incorrect for this application.



    I know we often confuse the terminology about what is called the primary loop with what is actually the boiler loop and that causes misunderstanding. If you were to pipe the boiler supply straight to the return (with a circ. in it) and then take the zones of that loop through closely spaced Tees, then the boiler loop would also be the primary loop.
    Bob Boan







    You can choose to do what you want, but you cannot choose the consequences.
    · ·
  • Jean-David BeyerJean-David Beyer Posts: 2,435Member ✭✭✭
    We seem to be defining primary and secondary differently.

    Depending on who I read, some people define primary and secondary differently. I forgot about this. And you and I seem to be using opposite definitions.



    Let me call the loop that has the boiler in it the boiler loop; and I will call the other loop with the loads, the load loop. I do not believe this is standard terminology, but that should eliminate confusion.



    This is all the more confusing because the picture provided hides the circulator in the boiler loop completely, and the closely-spaced Ts are disguised behind the Spirovent. Not only that, the return part of the load loop is hidden behhind the supply part of the load loop.



    There is a circulator in the boiler loop, hidden behind the expansion tank. According to the O.P., that circulator pumps down from one (I imagine the one on the left) of the two closelly-spaced Ts to the return input of the boiler. All the other circulators, and the spurious mixer valves are in the load loop. Four of them look parallel, and the one for the indirect is actually a fifth parallel circuit.



    So this is a true primary-secondary setup, where the secondary, that I call the load loop here, is a bunch of sub-loops in parallel. (The load loop could be piped as a series loop with another bunch of closely-spaced Ts). And nothing that happens in the load loop can affect the flow rate in the boiler loop, though it will certainly affect the temperature in the boiler loop.



    The only troble with the mixing valves, if I understand this piping correctly, is the unnecessary expense, the unnecessary complexity, and the need to run the boiler about 15F hotter than would otherwise be necessary to account for the necessary temperature difference required by the mixing valves. If I (a non-professional) were to pipe this, I would have put the indirect across the boiler loop so as to eliminate the need to run the boiler loop circulator when heating the indirect.
    · ·
  • SUPER DAN P&HSUPER DAN P&H Posts: 45Member
    Thanks all for your input.

    My primary/ secondary piping is 1 1/4" w/ 1" takeoffs for the heat and hot water maker zones. The manifolds have purge valves and the hot water maker has a float vent. I used clear primer to keep job neat. The gas is at 6" water column. I dont have a air problem in the system. I notice that the fan is vibrating at start up. Thats what seems to be giving me a problem. Any new ideas fellas?
    SUPER SERVICE WITH A SMILE!
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