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I fired it and walked away...

Dave_12
Dave_12 Member Posts: 77
I have a feeling that what you have is not a true primary - secondary system. We have sold a lot of these thermic valves and they are great, so I don't think that it is the problem, nor are the pumping rated. I've prepared two drawings, one I've labeled 'Original' which is what I am interpreting your system to be and the second suggested which is what I think it should be. I'm not at work where I have my full range of drawings so I threw these together pretty quickly and didn't show expansion tanks etc.

If my interpretation is correct (fellow wallies please advise) then I suggest two tweaks to your system.

1. Revise the piping as suggested to make it a true P-S system.

2. Place the controlling sensor in the system loop and use that as a setpoint. Use the existing boilers aquastat as a high limit and wire this in series to a new control. An aquastat would work OK, an I/O reset control would work fantastic.
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Comments

  • Timco
    Timco Member Posts: 3,040


    Of course, after testing. I get there this morning, and cust says never heated. The pri loop was sure hot, but through the bypass, not the pri loop. I had the secondary soo restricted that the zone would not heat all the way around. I cut out the spring check just after the 007, and was able to add more secondary flow to the mix but could not just open the secondary return valve, or the pri return cooled too much and the TV closed to bypass only...even with the bypass 3/4 closed. I am assuming that I need a 0011 to get a better flow around the primary to mix with the ret of the secondary better. Opinions? Thanks,

    Tim
    Just a guy running some pipes.
  • Cosmo_3
    Cosmo_3 Member Posts: 845
    I just looked closer

    I think you have the thermic bypass valve installed wrong. Take a look at the arrows on the sticker. When facing the valve looking at the sticker on the service plate; the bypass pipe connects on top, the return from the system on the left, and to the boiler return from the right hand tapping.

    As a quick fix you can just remove the guts of the TV, and close the bypass valve until you can get back to the job and re-do.

    I apologize for not picking this up before, hard to see clearly in the pics.

    The only restriction on the primary loop is the 10 or so feet of pipe, the TV valve, and the boiler. You do not need a bigger circ. I cannot see the entire primary loop, because it extends behind the water heater, but I assume it just loops back to the TV valve.

    Cosmo
  • Tombig_5
    Tombig_5 Member Posts: 60
    Timco

    Are you sure all the air is out? If the secondary pumps are 15-58's w/ flow checks try them on low speed. If they're not FC you need checks above the zone pumps. Is that the check you removed between the bypass tee and the close tee's?

    As a last resort you can nix the close tees, drop your return to just before the ESBE and run it as system bypass with the thermal valve rather than P/S

    Good luck, yeah and what Cosmo said
  • Timco
    Timco Member Posts: 3,040


    There is a spring check on the loop just before the TV as well. (to stop migration on a DHW call...future) The sticker on the TV shows the flow comming from the right, and heading to the boiler to the left. I wanted to install the valve with the sticker out, but the arrow pointed towards the system, not the boiler. If the boiler was to the right of the system, then I would need to reverse the valve. Am pretty sure on that one. Any other thoughts? Thanks,

    T
    Just a guy running some pipes.
  • Tim..

    The primary pump only has to move enough water in GPM to create the differential in temperature that you are looking for. For example, that appears to be around a 200K boiler, at 80% efficient, it would have an output of 160K. If you want to see a 30 degree delta T, then divide 160K by 8.33, then by 60, then by 30 to find the GPM. In your case, the answer is 11 GPM. The 007 would need to generate enough head pressure to over come the pressure drop of all the components in the primary circuit with a flow of approximatley 11 GPM.

    Using Siggy's Super Hydronic Software, I have calculated that you would get approximately 17 GPM, which should equate to a temperature differential of approximatley 19 degrees F.

    As previously stated, provided that you don't have the TV installed backwards, AND provided that you have choked the bypass valve per the installation instructions, once the primary loop is above the TV set point, any excess heat will be sent out to the loads PROPORTIONALLY.

    If, when you closed the bypass valve, you felt a little heat flow out to the secondaries, and a slug of cold water came back to the boiler, the TV is working correctly. It closed the return, opened the bypass and protected the boiler from thermal shock and long term condensation production.

    Trust me, when set up right, these things are the bees knees.

    ME

  • Timco
    Timco Member Posts: 3,040


    Purged very well, and those are FC 15-58's. The check I cut out was just past the bypass t, in front of the close spaced tees. Circs were on low, and would not move water through the entire zone...just the closest rads. (two-pipe, direct return conv. gravity zones) With the pumps sped up, the system circulated proper, but TV closed due to cold return and then the close spaced tees just re-circulate and system never heats...

    T
    Just a guy running some pipes.
  • Cosmo_3
    Cosmo_3 Member Posts: 845


    Still not sure about the TV valve, the pic is not clear enough for me to see the label.

    By all means if I am wrong, then yes check for air as Tombig suggests.


    Cosmo
  • Timco
    Timco Member Posts: 3,040


    Exactly, but the system never progressed to hot, even over night. I choked the bypass, and the secondaries heated, but then instantly cooled because the TV closed and the close tees just recirculate. I had to choke the secondary return so low to get the primary loop hot & flowing that I lost flow through the zones...not enough flow. RAn all night and zones never heated.

    T
    Just a guy running some pipes.
  • Timco
    Timco Member Posts: 3,040


    The lable faces the wall to get the proper direction...

    T
    Just a guy running some pipes.
  • Cosmo_3
    Cosmo_3 Member Posts: 845
    Okay

    So you have the valve installed okay. I would first check to see if any garbage got into the TV valve. Happened to me, yes as careful as we are sometimes crap gets in the piping.

    Of course won't be easy as installed.

    Give us some specs on the system. What are the secondary loops flow and btuh requirements? What kind of radiation? Maybe you need a larger TV valve. The first TV valve install I did I included a Bypass of the TV valve for emergencies.

    Cosmo
  • Double check all parameters...

    Clock the boiler. Is it firing at the right rate?

    If this is a garvity conversion on a multi story home, there may be restricive orifices on the upper floor radiators.

    If this is a MASSIVE cast iron and steel pipe system, it will react slowly. Especially if it has been cold for a long period of time. But you should feel a difference over night.

    With this being a gravity conversion, I guess it is entirely possible that the TV locked up due to ferrous oxides (rust) in the system. If that is the case, replacement is realtively simple.

    Fall back and regroup. You WILL overcome the obstacles.

    ME
  • Timco
    Timco Member Posts: 3,040


    Monday I will recheck all parameters. I will pull the guts out of the TV and look for crud as well. Here is the valve, and if you compare the pic to the install, the arrows are correct. Just cannot figure out why in the H#$l it is not just a runnin'....

    Tim
    Just a guy running some pipes.
  • Timco
    Timco Member Posts: 3,040


    If the TV allows FULL bypass until the RETURN reaches 140, then how will the secondary ever heat? Are these made for p/s systems?

    T
    Just a guy running some pipes.
  • Weezbo
    Weezbo Member Posts: 6,232
    are you near the job?

    take a 6 ->10 foot, washing machine hose and connect it to the purge above the return from the "field" and then connect the other to the return ahead of the boilers return ball valve.... turn the boiler off and the farthest circ into the field On, let it run twenty mins and note the temp of the boiler before and after...subtract the one temp from the other...what is the temp differential?
    try the next pump after running the boiler back up,... same deal...
    then one more time just for good measure with the last of the three....

    care to share what you find?
  • Timco
    Timco Member Posts: 3,040


    So I am bypassing the TV as well as the entire pri loop? Let the boiler fire, but close the purge valves on the secondary return and the primary return? If the system heats normal, is my TV the issue? As I mentioned, looking at the posted instructions, if the TV allows FULL bypass until the RETURN reaches 140, then how will the secondary ever see heat??

    Thanks, I'll try that too Monday.

    Tim
    Just a guy running some pipes.
  • Weezbo
    Weezbo Member Posts: 6,232
    i do not know this particular boiler..however

    with the way you have it lashed up it ought not to require much more than running it up to temp to establish flow with out a circ...the fact that you have three one for each zone...that makes me think there is a "Magic" Valve somewhere in the system that is closed...any Gates in the field? maybe you lost a gate, and ,the bypass is clogged...it would be good to have a temp gauge on the return to the boiler just for the heck of it sorta speak :) do you own one of those spring wrap pipe temp gages? it is a handy item...

    let me see if i can find a picture re size it get it on my desk top and add it as an attachment...that's a lot for me to do :)) might be tomorrow by the time i get that done:) oh well see you in a bit washing machine hoses are my "favorite by pass" in conjunction with some no kink hose bibs placed strategically round about the headers and secondary piping...:) reason being we are in a constant battle with the cold....

    Cosmo has a definite ok wheres the rest of the loop...if it is dead heading down there that be's a problem...because it will act just as Mark said, it will see a massive Slugg of water go "OOOPs"and the by pass will work like a top:)

    if you have two no kinks on the end of supply and the return put a wasing machine hose on them too,..then it will mix up the temps almost like a pinner gravity loop of its own...
  • Timco
    Timco Member Posts: 3,040


    I taped my fluke temp probe ( bacharach probe) to the return before the TV and watched the temp drop from 160 to 100 and lower (whatever the return temp is) as soon as the secondary return is opened past 1/4. Boiler is your standard 162K Crown atmospheric boiler. Tested well, fires great. With the return closed off, the primary works & flows well at full temp. just when secondary return hits the loop does the TV close quick...the temp drops fast. No other gates on entire system I could find. I went 3 seperate circs to balance the system better. It had one large B&G.

    Tim
    Just a guy running some pipes.
  • Weezbo
    Weezbo Member Posts: 6,232
    Hmm....

    right now i have one slantfin Intrepid oil fired boiler running 140 back and stroking 14? heading out into the field....the field is about 6000 feet plus change of radiant .it is real slow to ramp....

    i have bypasses in the field at two of three substations. it is pretty chilly here just about now...the 16' shop walls have no insulation in them the ceiling is all open to the crown. on a 4 12 ,with some *visquine on the gable vent end opening..and some more dropped across the Overhead doors in two of the seven shops within this building *~/:) sorta Snow and Ice melt within a building*~/:) luckily the skin is on the exterior walls and the roof is dried in, with sheathing on the dividing walls 60'X16' and the windows are in the offices :) yes it is a bit chilly in there buh it is way chillier outdoors:) and the boiler rooms crankin:) it must be all of 40 in there:))

    sorry, i digress.
    thought was ,you really really want that return temp hanging in there...that little pinner boiler is not like some old style two ton chunk of iron...and as highly as i think of the slant fin ( i considerd parking it outside on a trailer with some camlock fittings on it and calling it good) :) it could droppout significantly any day now and even though ive cranked the Slantfin 30 up in 30 below zero i dont like putting them to the task that hard as a rule...plus they melt into the snow and ice and then you got to wonder if you will be able to extract them out of the garage floor in time for the cement truck :) sorry,...deal is 140 is a good number to designe the system return around..boiler like you much better..now if it was a Viessmann or the FCX monitor buh thats another story :)




    the trick to the whole deal is simply protect the boiler and make it work *~/:)

    *more commonly known as polyethylene sheathing
  • Timco
    Timco Member Posts: 3,040


    I feel guilty working with such a small boiler in a warm mech. room...I get your drift. 140 ret, and design the system around that. I just now need to figure out how to raise the secondary ret temp so it does not close the TV and hopelessly cycle through the close tees. Thanks for the advise. I will try the wash hose trick.

    Tim
    Just a guy running some pipes.
  • Dave_12
    Dave_12 Member Posts: 77
    Two Questions?

    1. What is going on with the piping behind the water heater? Draw it out if you can so we can see what is happening. I think a piping change may be in order, but can't tell for sure.

    2. Where are you looking at temperature? Are you running off just the boilers internal aquastat? What is it set at?



  • Tim...

    With the bypass valve choked to 3/4 throttle, I suspect the system is working exactly as it is supposed to work. It sounds like you are doing an extremely cold start.

    Check it again, and come back with temperatures at the following locations. T1 would be the secondary supply, T 2 is the secondary return. T3 is the supply water on the primary right before the secondary takes off, and T-4 is the water going into the boiler. Make notes also of the water temps coming out of the boiler.

    Let me ask you a simple question. Does the boiler run all the time? Or does it short cycle off of its high limit. If it runs ALL the time, then the system is working as it is supposed to. If it short cycles, then its broke. Simple method of diagnosis.

    If it runs all the time, and your combustion analysis numbers look good, that heats going somewhere, no?

    Check it out and get back to us.

    ME
  • Weezbo
    Weezbo Member Posts: 6,232
    That is the deal that Mark is saying...

    if the boiler is cranking '140 return' on my boiler Into the boiler return and the temp starts to fall, leaving the boiler ....the boiler gets into a steady Run Mode and it will fight the cold until either the boiler wins or the cold does :) however, i will go put it in Full Bypass in that event and i know it will hold its own to some extremely cold temps..the field wont see heat :) it will all stay at the boiler for the duration...

    the trick to what Mark is saying is take your time and dial one zone up at a time...


    Ok Mark has got me thinking what IS the current temp and pressure setting on the boiler? ok what IS the high limit set at? is the control a cold start ...room temp to max limit control? because.... ahh,,,now minor technicality small variable...

    ok so .... then you could also bump the boiler temp up 20 degrees and make it 200 instead of 180.....leave the lower setting alone for a while only dial one loop at a time and keep an eye on the boiler temps....if it goes up to 200 and is working ok then raise the lower temp up to 170....then try the next loop...might be the same slow rolling deal again..



    ok. i had difficulty with this picture sizing etc... thing is on this loop there are two gages ....that way in 45 50 below one can tell at a glance what is happening with the slab on grade radiant temps supply and return, the ball valves is to isolate the injection pump and to dial the temps to what i want it to be during a cold start,...in reference to my return boiler temp.

    this pic isnt great however you can also make out no kink Purge valves on the Return and supply ..what you dont see is the same on the other side of the injection system and at the sub stations that way i can by pass the injection system,the 'Field or 'System pump' close a valve and turn the primary seconday open a couple bypasses hook up some washing machine hoses and basically dial a specific temp out to the field... through a series of step down and step up bypasses...the esp valves allow another choise..popping on some I series set point or I seriesR as an up grade on homes with multi temp systems with an admixture of baseboard convectors and radiant slab on grade or slab on grade Gypcreye some high heat coil and base board, and the indirect ..

    the Taco guys must LOVE me :)))sorry, i digress...on some baseboard convector systems i might go with a setpoint control on the by pass back to the boiler so that the radiant doesnt "swamp"the boiler.


  • Timco
    Timco Member Posts: 3,040


    Nothing behind the WH but two 90s. The CV of the ESBE valve is 16.4. I am looking at temp just prior to the check on the primary...seeing if the bypass is taking over or if flow is making it through the entire primary loop. I am thinking I have flow reversal as the sec rates may be exceeding the primary rate with the TV and a spring check. Aquastat is set 180. When sec ret is closed, I get 150 through the primary loop's return. Any sec return kills the temp and shuts the valve. Thanks!

    Tim

    Tim
    Just a guy running some pipes.
  • Timco
    Timco Member Posts: 3,040


    Mark & Weezbo,

    Thanks to both of you for your time! I will take temps, but I can say that Sec supply stays same temp as sec return. (reverse flow) Boiler Short Cycles like a mother!!! Only runs longer as the sec return is throttled way back and heat runs through the sec supply, but is too low of flow rate to heat the long conv grav zones. Just the closest rads...least resistance. Aquastat is 180, and I get 155 or so on the pri ret when the sec ret is closed and the pri actually flows around.

    Tim
    Just a guy running some pipes.
  • Timco
    Timco Member Posts: 3,040


    Aquastat is 180, press is 15#...3 story residence. Cold start system. Returns are room temp.

    T
    Just a guy running some pipes.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    Timco

    I am watching with interest to see what the solution is. I also want to ask, what are you using to strap your expansion tank? Looks good. Where do you get them and how much are they? WW

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • I've slept on it... Primary loop is not purged...

    If you're making it hot, and its NOT making it through the primary loop, then you have thermal constipation on the primary.

    Do this. As long as you have adequate isolation to the point that you can drain the lower end of the system to do some minor piping changes without having to drain the whole shebang, put a bypass over the top of the TV on the return. Use one pipe size smaller than the mains are currently piped for and include a ball valve in that bypass. You've been trying to purge the primary through a 1/16" hole in the thermostat's base. Ain't NO WAY that puppy is purged. With the other check vavle you put in near the boiler return, the valve body can't bleed itself naturally backwards, so that section of piping is still air bound. Once you have it purged, you can manually adjust the bypass valve over the TV and get the system kick started. Once you've got it hot and purged, close the TV bypass and normalcy will take over.

    Expect the boiler to condense while you are kick starting it. You will hear sizzling in the combustion chamber, and your CO numbers will be extremely high due to the flame being fouled by the condensate.

    I knew I was forgetting something, and the factory drawing does not show a bypass. It's something our field guys anticipated and threw into the mix to overcome the purging issue.

    I'm taking the little lady out to breakfast this morning, and will come back and whip out a drawing for you later.

    Relax, it's Sunday...

    ME

  • Timco
    Timco Member Posts: 3,040


    Thanks, Mark...yes, relax today. I will go over and pull the TV guts to get them heat. Tomorrow I will add the bypass. Mr. Wayne, the straps are your every day 10" rigid unistrut straps, $7 each.

    Thanks,

    Tim
    Just a guy running some pipes.
  • The fix...

    OK, I've changed a few things reflecting how I WOULD have done it, and not to say that yours won't work, just that mine is based on labor savings. I'll explain that later in this post.

    Note the valve bypass around the TV. This will allow you to fully purge the primary, which I'm pretty sure you haven't acheived yet, and will allow you to "slip the clutch" around the TV. Personally, it is my experience and professional opine that you shouldn't need to slip the clutch to get the mass moving. That IS the reason you have the TV in there. Let IT do the "clutch" controlling.

    Once you get the primary purged, the system should take off, the boiler should run wide open, and the secondary should GRADUALLY get warmer and warmer until set point is satisfied. Don't worry that your secondary is remixing with itself. A btu is a btu, and it doens't care if it gets thrown back into the mix, and neither do your radiators care. All they're looking for is heat, slow gradual heat...

    The other modifications I have made are as follows. You will note the full port ball valves between all the closely spaced tees. This is to save time in purging. You close this ball valve when purging and essentially put the circuits into a series circuit, and purge from a single point, as opposed to having to move the hose around from purge point to purge point. Every minute saved in the field is money in the bank.

    In your case, with the distribution system being a high mass cast iron radiator system, you can not power purge that part of the system any way and will have to bleed from bottom to top in order to fill the radiators anyway. (I am assuming bottom tapped radiators as opposed to bottom in, top out)

    Note also that I have eliminated the checks you had on the primary loop. The place for those checks is on the secondary loops where you have excess pump head capacity. Note that there are checks on both the secondary supplies and returns. Note also that they are SPRING checks, not SWING checks. With enough elevation, gravity can overcome the close off capacity of swing checks and cause ghost flow (gravity flow) conditions that will cause the heating system to heat up after each DHW cycle. Not fun in the summer.

    Having upper system isolation and drain capability is a good idea, because it allows you to work on the upper end of the system while keeping the bottom end of the system up and running for DHW (think future remodel during non heating season), and vice a versa, you can work on the bottom end of the system without having to drain the upper end of the system, like when you discover that there ARE restrictive orficies in the upper floor radiators...

    Another advantage of having the ball valve between the secondary tees is that if you get a call that they have no heat on a Sunday, and find that there is a dead pump on either the primary or the secondary, you can partially close that ball valve and exert flow for temporary heat until the warehouse opens on Monday.

    Do this and I guarantee you bottom line human comfort or my name is not Orville Reddenbacher :-)

    Orv
  • So, Brant...

    What exactly do you see as being different in the two drawings that you've presented?

    In my minds eye, they are essentially the same. No?

    Please splain it to my minds eye, which sees things differently than most:-)

    ME
  • Dave_12
    Dave_12 Member Posts: 77
    Subtle Difference

    Mark -

    It is a subtle difference, and it is difficult to put into words. I think I would need a powerpoint presentation and about 2 days to prepare it to really explain what I see in my mind, but I'll try.

    Basically, the original system is not a primary - secondary system. What occurs in one loop does affect the pumping of the other loop. When the thermic valve is closed, the pumps don't see each other - see the attached drawing. However, as soon as it hits 140 and starts to modulate, wierd things start happening. Again, I can see it in my mind but find it difficult to explain.

    To paraphrase DH, what goes into a 'Tee' must come out of a 'Tee'.

    Perhaps I can introduce my own phrase -

    "Two closely spaced Tee's doth not a primary-secondary system make"

    -- Brant

  • brucewo1b
    brucewo1b Member Posts: 638
    Brant

    I thnk all you have done in the Sujested drawing is create more resistance in the primary loop however if you put closely spaced tees in the primary also pull the bypass w/ the ESBE and put a diverter tee in the return between the two loops then we would be talking control. I may be wrong but that is my take.
  • Timco
    Timco Member Posts: 3,040


    Brant,

    Thanks for the input. This is a very interensing discussion and I am grateful for all the help & suggestions. I have the definition of p/s as a method of interfacing individual secondary distribution systems to a common primary system. Your drawing of my layout is correct. As I see it, would your drawing not break the primary circuit, and allow the secondary to just flow through it's loop? It almost seems the second drawing is a 4-way mixing valve with no control? Who would win would depend on the greatest flow rate? In all the examples of p/s, the secondaries are taken off the pri directly with the close tees. The only thing that interferes with the p/s setup is the variable for the TV, which isolates the secondaries completely. I would like to see both drawings on a simulator to see what would take place, but another time...Thanks again.

    Tim
    Just a guy running some pipes.
  • Timco
    Timco Member Posts: 3,040


    Update...

    I called the HO to come by and remove the TV guts, and before I could say anything, he says it was soo hot in his place he had to open windows! I had the aquastat set for 180, and the t-stat overridden to let the system run and run. I had the sec ret wide open. I nursed the sec loop a while yesterday to try and temper the ret temps and left when they were at 100 or so. The 1) air must have finally bled itself out as Mark suggested, or 2) sec temps finally got to a point where they did not shock the TV into full close. Either way, we will see if after being satisfied, if the same problem occures on a cold start-up or if we are good. Last question I have is in applying a outdoor reset. (Tekmar 260) If it needs 140 to stay open, and the reset kills the boiler at 140, what will happen? The reset limits or gets in front of the aquastat and limits the boiler temp depending on outdoor temp...no?

    Thanks to everyone. I will keep all informed.

    Tim
    Just a guy running some pipes.
  • Weezbo
    Weezbo Member Posts: 6,232
    Hurray! Orvil told you true *~/:)

    even without his mind reading hat on hes a bad boy at this :)
  • Dave_12
    Dave_12 Member Posts: 77
    P-S Systems

    I've had to re-think myself a few times, yours is a P-S system. With my suggested drawing, I ended up swapping which loop is primary and which is secondary.

    You are right, mine is sort of like a 4-way valve, it provides two mixing points.

    I can see how your system heated up and will work, I still am convinced mine would work better, but that just may be me being stubborn.

    To run yours correctly, you definately need to put a sensor in the system loop and run based on that temperature. The boiler aquastat gets set up in series with it and is like a high limit then.

    Too much thinking for a Sunday, football is on, go Chiefs.

  • Brant, Define PRIMARY...

    AFTER the game...

    Go BRONCO's!

    ME
  • Timco
    Timco Member Posts: 3,040


    Ouch!! A 3rd qut interception!! Did I mention I am a life-long Raiders fan?

    Tim
    Just a guy running some pipes.
  • Dave_12
    Dave_12 Member Posts: 77
    Primary -

    Strangely, I was thinking about posting a separate subject on the matter.

    I define the primary loop as the loop which has the two closely spaced tee's in it. The secondary loop is the loop which pulls from the primary loop.

    I believe there is some confusion in the matter and I often just use boiler loop and system loop(s) when speaking about them.

  • Cosmo_3
    Cosmo_3 Member Posts: 845
    Update?

    I haven't checked back for a while, Were you there today Timco?

    Did I guess right, about the air? I have found like ME suggests that it is easy to purge when you install a bypass past the TV valve.

    Let us know

    Cosmo
This discussion has been closed.