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Flush / refill hydronic floor system - need help, please

TahoeJohn
TahoeJohn Member Posts: 20
Hi, new user here. We have a hydronic floor system with two boilers, 4 pumps, Wirsbo valves, PEX tubing, etc. It's time for a system flush and refill, but unfortunately the guy we always used has retired and we can't seem to find a contractor in the area who works on these systems. I'd like to have a go at this myself.

I'm thinking that it should be flushed with fresh water to get rid of all the old fluids, and then filled with a propylene glycol solution. Do I flush until the system is completely full of fresh water and then pump in the PG? Does it usually come in a concentrate that gets diluted with, say, 50% water? How should I dispose of the old PG?

There are valves in the system that should let me flush/fill each of the four zones plus the two boilers, each independently. I have a small drill-mounted pump, short hoses, etc.

Thanks for any pointers you can share!
John

Comments

  • STEVEusaPA
    STEVEusaPA Member Posts: 5,977
    I think you should keep looking for another professional. The 'guy' should know someone else, so should the local supply houses.
    You can check 'find a contractor' on this site or maybe try:
    https://www.radiantprofessionalsalliance.org/
    steve
  • TahoeJohn
    TahoeJohn Member Posts: 20
    Thank you, Steve, but I guess I should have added that I enjoy doing DIY projects if I can get educated on how to do them properly.

    Since I first posted, I found the Hercules "Cryo-Tek -100" that I need for this, along with their specifications on how much to dilute for various levels of temperature protection.

    My system holds just under 80 gallons total, so I'll need to get 40 gallons of the Cyro-Tek. Unless I'm missing something (which is certainly likely), this actually seems fairly straight-forward to me.
  • GroundUp
    GroundUp Member Posts: 1,495
    Back up the bus a bit here. What type of system is this which requires 2 boilers and holds 80 gallons of fluid (how did you calculate that?), plus requires glycol? A large farm shop or commercial warehouse which is unheated at times perhaps? The freeze protection numbers are not really what to shoot for with these systems- it's concentration more than that number. Cryo-Tek -100 is 55% out of the jug, and your final solution should be no less than 30% (if you even need any at all) so 40 gallons would not be enough. Also, if you try to purge an 80 gallon radiant system with a drill pump you're going to need 2 haircuts before it's purged.
    SuperTechHVACNUTAlan (California Radiant) Forbes
  • TahoeJohn
    TahoeJohn Member Posts: 20
    Hi GroundUp, thanks for the help here. As I mentioned, I'm trying to learn, so here goes:

    This is for our house. It has two boilers at 34 gallons each, plus 7 heating zones branching from 3 manifold locations. I spent the time to do a more accurate calculation this morning and came up with 118 gallons of capacity (admittedly my first 80 gallon number was quite low).




    I based my "1 to 1" dilution from the Cryo-Tek spec sheet, simply assuming that if they list it as a possible ratio, it must be okay. Where we live it almost never gets below 25 degrees outside, so I was simply going for the minimum freeze protection listed.


    I'm assuming that this system requires glycol because my installer always used that, both for the initial fill and for a mid-life service 10 years ago.
  • Zman
    Zman Member Posts: 7,434
    Some pictures of your system would help. Everyone sets up the purge points differently.
    A few pointers:
    • Test your water now. Is it dirty? If you pour some into a clear container do particles sink to the bottom? If so, do the particles move if you pass a strong magnet by the glass? How is the PH and TDS?
    • If your water is really bad, you should purge, then let a cleaning solution circulate for a few days, and then purge again.
    • How is your tap water? if it is not great, you might consider treating it or importing.
    • To refill the system, do yourself a favor and get the right tools. Something like this would work https://www.supplyhouse.com/Liberty-Pumps-331-1-2-HP-Portable-Aluminum-Transfer-Pump-Garden-Hose-Connection-115v-20-ft-Cord
    • Get a super solid plan before you start. If you don't have good purge points isolation valves and a plan, you will airlock it and make a hot mess of it all.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • GroundUp
    GroundUp Member Posts: 1,495
    What model boiler holds 34 gallons of fluid and why are there 2 of them for only 4000 sq ft or less? Unless the space is sometimes unheated or unoccupied, glycol is more of a harm than a help. Concentrations below 25% tend to become acidic much faster than higher concentrations and thus require more frequent maintenance- either 30%+ or none.
  • TahoeJohn
    TahoeJohn Member Posts: 20
    Zman said:

    Some pictures of your system would help. Everyone sets up the purge points differently.

    Sure, here is the equipment:





    A few pointers:
    • Test your water now. Is it dirty? If you pour some into a clear container do particles sink to the bottom? If so, do the particles move if you pass a strong magnet by the glass? How is the PH and TDS?
    Here's a sample. It seems fairly clean to me, no solids that I could see. pH is 7.2, but I don't have a way to measure TDS, unfortunately.



    How is your tap water? if it is not great, you might consider treating it or importing.
    I think it's pretty good and measured to be soft.
    To refill the system, do yourself a favor and get the right tools. Something like this would work https://www.supplyhouse.com/Liberty-Pumps-331-1-2-HP-Portable-Aluminum-Transfer-Pump-Garden-Hose-Connection-115v-20-ft-Cord
    Thanks, good idea!
    Get a super solid plan before you start. If you don't have good purge points isolation valves and a plan, you will airlock it and make a hot mess of it all.
    Here's a picture of the two purge points in the system. Note that these are downstairs from most of the house.



    At this point, my simple plan was to flush the system with tap water, drain the two boilers, fill those with 60 gallons of Cryo-Tek -100 plus enough water to fill them up, and then turn on the system and let it purge out any remaining air. However, I'm open to learning what's wrong with this plan and how better to get this done.
  • TahoeJohn
    TahoeJohn Member Posts: 20
    GroundUp said:

    What model boiler holds 34 gallons of fluid and why are there 2 of them for only 4000 sq ft or less? Unless the space is sometimes unheated or unoccupied, glycol is more of a harm than a help. Concentrations below 25% tend to become acidic much faster than higher concentrations and thus require more frequent maintenance- either 30%+ or none.

    Here's a picture of the label. Note that I'm calling it a "boiler" but it's really just a direct vent propane water heater.



    The total area of hydronic floors is about 5200 sq-ft.
  • Zman
    Zman Member Posts: 7,434
    Draining and filling the water heaters would be a simple way to change that fluid. I would caution you that if you put 100% glycol in the tanks and run the circs, the "mixing" you will get will be more like whipped cream which will airlock the system and make a big mess. I know (was) that guy. :s
    I would suggest premixing your glycol and filling the tanks. You will then want to put your transfer pump hose on the hose bib at the pump manifold and a drain hose on the return manifold. You will want to close the gate valve on the return manifold so the glycol cannot take a shortcut. Close all the ball valves to the zones and open them one at a time until you see the glycol come through.
    It's not really quite that simple but that should get you going in the right direction.
    There are probably some videos out there that will show you how to manage the purging process back into a bucket until you see a consistent air-free mixture.
    It is a good idea to premix the glycol a bit stronger than you need to make up for the dilution that will happen.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • TahoeJohn
    TahoeJohn Member Posts: 20
    Thank you, Zman, extremely helpful! The process you describe about running the mixed solution through the zones one at a time is what I dimly recall my service guy doing 10ish years ago. Now I see why.

    So the steps, as I understand them:
    1) Flush the entire system with tap water
    2) Drain the boilers
    3) Fill the two boilers with premixed solution
    4) Isolate the boilers (gate valve)
    5) Pump premix into each zone, one at a time, discarding the water until I see glycol
    6) Pump through each zone, one at a time, until no air, using a single bucket to pump from/to

    Do have the basic process down?

    I can also now understand why I need a good pump for all this...

  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    Tahoe John, You're in Tahoe? What is your elevation? I'm not looking up your Polaris W/H's, so, is that doing your domestic hot water, too?

    Water less than 25% glycol can be a source of food for bacteria. You need a Refractometer to accurately dilute the glycol. 5 gal of Hercules AG might be a better value. It is 95% glycol. Zoro.com has reasonably priced Hercules glycol.

    I do this for a living and it's difficult to get the air out of the sys some times, and I have the right tools. It might be more prudent to have it done by a hydronic specialist. What's your nearest city?

    I think that there are You Tube videos that might be helpful if you decide to do it yourself. Education is key to a successful job.
  • TahoeJohn
    TahoeJohn Member Posts: 20

    Tahoe John, You're in Tahoe? What is your elevation? I'm not looking up your Polaris W/H's, so, is that doing your domestic hot water, too?

    Nope, we're around 1800 ft elevation. Those two Polaris water heaters are only for this hydronic floor system.

    Water less than 25% glycol can be a source of food for bacteria. You need a Refractometer to accurately dilute the glycol. 5 gal of Hercules AG might be a better value. It is 95% glycol. Zoro.com has reasonably priced Hercules glycol.
    Got it. I think this is what GroundUp was saying originally, too. So here's how I would calculate things:

    Cryo-Tek -100 is 55% glycol, or 2.75 gallons of glycol per bucket.
    My system is 132 gallons, so for the desired 30%, I'd need 40 gallons of glycol.
    At 2.75 gallons per bucket, that's 14.5 buckets.

    Thanks for the pointer to Hercules AG, but I've already ordered 9 buckets of -100 so I'll just order 5 more.
  • Zman
    Zman Member Posts: 7,434
    I think you understand the process. Best of luck!
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    TahoeJohn
  • GroundUp
    GroundUp Member Posts: 1,495
    But again, why glycol? You're not in a cold climate. Unless you are shutting the place down and allowing it to freeze, there is no need for glycol- it's more of a harm than a help. Not to mention a big waste of money and headache
    WMno57
  • TahoeJohn
    TahoeJohn Member Posts: 20
    GroundUp said:

    But again, why glycol? You're not in a cold climate. Unless you are shutting the place down and allowing it to freeze, there is no need for glycol- it's more of a harm than a help. Not to mention a big waste of money and headache

    This is a good question and sorry I didn't respond previously. I agree that we don't need to worry about freeze protection. My motivation is simply to preserve the service life of the system. Cryo-Tek has "anti-corrosive additives", whatever that means, which sound good to me, at least on paper. And since the installer used glycol (originally and again about 10 years ago), I was just assuming that it's a necessary thing.

    What is the alternative? Just run pure tap water? Or leave the system alone and not do a flush at all? It's a 20 year old system. Everything works fine, so again, I just want to do what's going to keep it running for another 20. If I should do additional testing of the existing water, I'm happy to do that.

    Thanks!

  • GroundUp
    GroundUp Member Posts: 1,495
    Corrosion inhibitors can be added to water too, and have the same or better corrosion protection than the glycol. Every drop of water you add to the Cryo-Tek takes away from its predetermined level of protection, so unless you're bringing the pH, nitrites, etc back up to spec after diluting the glycol you're potentially creating more corrosion than if it were just pure water with no additives. It honestly doesn't even look like there is glycol in your system, as the lines appear to be clear. Have you ever tested the fluid with a refractometer or even the test strips you can get at the big box to see what you actually have? Glycol has a lifespan, as you are aware, so if it is in fact glycol, 10 years is probably long enough to replace it with something but not necessarily more glycol
    PC7060WMno57
  • TahoeJohn
    TahoeJohn Member Posts: 20
    GroundUp said:

    Have you ever tested the fluid with a refractometer or even the test strips you can get at the big box to see what you actually have?

    There's probably a special refractometer for this kind of stuff; unfortunately all I have is the one I use for making beer, so these numbers may not make any sense: The current fluid has a specific gravity of 1.018 (or a Brix of 4.5). Does that mean anything useful?

  • Derheatmeister
    Derheatmeister Member Posts: 1,342
    Why Glycol with all the inherent issues....Do you have any overhangs or piping that can be subject to freezing conditions?
    If you do not have exposed piping then why not adhere to the VDI 2035 ?
  • TahoeJohn
    TahoeJohn Member Posts: 20

    Why Glycol with all the inherent issues....Do you have any overhangs or piping that can be subject to freezing conditions?

    No. I'm finally getting it through my meathead that we don't necessarily need glycol. I've cancelled my order for the 9 buckets of Cryo-Tek while I try to figure out what to do.

    If you do not have exposed piping then why not adhere to the VDI 2035 ?

    Well there you go, dropping knowledge on me. I had never even heard of that... more learning to do.

    I guess I need to figure out what the pH, TDS, conductivity, salts, and total hardness is for my tap water. And then somehow go from there.

  • HomerJSmith
    HomerJSmith Member Posts: 1,927
    Rhomar can test your water for you. Water chemistry is important for longevity.
    TahoeJohnkcoppZman
  • Tim Potter
    Tim Potter Member Posts: 272
    We are at 9000' in Winter Park, CO, design temp is -30*. I used Fernox "express" F3 cleaner, flushed well with tap water, & then F1 "Express" Protector. The Express version makes it easy to add to your system.
    I was advised against glycol by the "Wall" advice, & have the water checked every so often. There has never been an issue with water quality. Rhomar makes a good product too, My distributor carried the Fernox line.

    Tim
    Winter Park, CO & Lenexa, KS
    PC7060
  • Derheatmeister
    Derheatmeister Member Posts: 1,342
    Applying the VDI 2035 is much easier than most Contractors think.
    1. Install a system cleaner (Same as you would with Glycol)
    2. Flush the cleaner.(Same as you would with Glycol)
    3. Install the deionized water via a Mixed Resin bed setup... Axiom Puropal/Magnetics VEP 300/VEP 1000. If you perform this task on a regular base to pays to purchase a Basic mobil mini or Basic mobile plus..
    4. After a couple months check your PH and EC to make sure it is within Balance.
    5. If you PH Drops ,Install a Sacrifical Anode such as the SorbOx or The HWR 10 plus or Compact Plus from Magnetic online.de
    Nowadays we allways install the HWR from the begining to avoid the roller coaster with the PH (Self alkalization process)
    IMO VDI 2035 it is better for the enviroment and cost less in the long run..No Chemicals involved.. :)
  • TahoeJohn
    TahoeJohn Member Posts: 20

    We are at 9000' in Winter Park, CO, design temp is -30*. I used Fernox "express" F3 cleaner, flushed well with tap water, & then F1 "Express" Protector. The Express version makes it easy to add to your system.

    Thank you, Tim. Looks like I could get both products on Amazon. Each is designed to treat 130 liters; for my system (closer to 500 liters), would you recommend I use 3 or each the F3 and F1?

    How did you install the F1? Drain off a bit of water after the flush and then just let it mix in over time?
  • TahoeJohn
    TahoeJohn Member Posts: 20

    Applying the VDI 2035 is much easier than most Contractors think.
    1. Install a system cleaner (Same as you would with Glycol)
    2. Flush the cleaner.(Same as you would with Glycol)
    3. Install the deionized water via a Mixed Resin bed setup... Axiom Puropal/Magnetics VEP 300/VEP 1000. If you perform this task on a regular base to pays to purchase a Basic mobil mini or Basic mobile plus..
    4. After a couple months check your PH and EC to make sure it is within Balance.
    5. If you PH Drops ,Install a Sacrifical Anode such as the SorbOx or The HWR 10 plus or Compact Plus from Magnetic online.de
    Nowadays we allways install the HWR from the begining to avoid the roller coaster with the PH (Self alkalization process)
    IMO VDI 2035 it is better for the enviroment and cost less in the long run..No Chemicals involved.. :)

    Great info, thank you!! Mostly makes sense, but a few questions:

    It looks like the Puropal just hooks inline with a garden hose, is that correct? (Hard to tell from their product literature.)

    When you install the deionized water, how do you tell when the flush water is gone and only the new deionized water remains? For example, with glycol, there's a color change, so you know when to stop pumping in the new product...

    Magnetic-online.de appears to only sell to professionals. Do you know of how/where I (just a homeowner) could get something like the HWR 10 plus?
  • Derheatmeister
    Derheatmeister Member Posts: 1,342
    TahoeJohn said:

    Applying the VDI 2035 is much easier than most Contractors think.
    1. Install a system cleaner (Same as you would with Glycol)
    2. Flush the cleaner.(Same as you would with Glycol)
    3. Install the deionized water via a Mixed Resin bed setup... Axiom Puropal/Magnetics VEP 300/VEP 1000. If you perform this task on a regular base to pays to purchase a Basic mobil mini or Basic mobile plus..
    4. After a couple months check your PH and EC to make sure it is within Balance.
    5. If you PH Drops ,Install a Sacrifical Anode such as the SorbOx or The HWR 10 plus or Compact Plus from Magnetic online.de
    Nowadays we allways install the HWR from the begining to avoid the roller coaster with the PH (Self alkalization process)
    IMO VDI 2035 it is better for the enviroment and cost less in the long run..No Chemicals involved.. :)

    Great info, thank you!! Mostly makes sense, but a few questions:

    It looks like the Puropal just hooks inline with a garden hose, is that correct? (Hard to tell from their product literature.)


    Yes that is correct


    When you install the deionized water, how do you tell when the flush water is gone and only the new deionized water remains? For example, with glycol, there's a color change, so you know when to stop pumping in the new product...



    A couple way that this can be done..
    1. Just circulate though the Puro pal via a Delta Tee that is created until the Color Changing agent is depleted. Depending on what your fill water quality is like you may need multipal Puro Pals
    2. You purchase a measuring Computer and install it on the Return

    Caleffi Idronics #18 has more infomation on this subject.

    Axiom also has some instructions on how to use the Puro pal.



    Magnetic-online.de appears to only sell to professionals. Do you know of how/where I (just a homeowner) could get something like the HWR 10 plus?
    Low Energy in Denver Colorado 1 800 873 3507 They also have the Measuring Computer
  • Tim Potter
    Tim Potter Member Posts: 272
    TahoeJohn said:

    We are at 9000' in Winter Park, CO, design temp is -30*. I used Fernox "express" F3 cleaner, flushed well with tap water, & then F1 "Express" Protector. The Express version makes it easy to add to your system.

    Thank you, Tim. Looks like I could get both products on Amazon. Each is designed to treat 130 liters; for my system (closer to 500 liters), would you recommend I use 3 or each the F3 and F1?

    How did you install the F1? Drain off a bit of water after the flush and then just let it mix in over time?
    The Fernox express come in a pressurized can As I recall, I opened a valve far away form the entry point & just let the can pressure do the work to install.

    I don't have access to my invoice, but the amazon price seems large, might check with your local hydronic supply to see what they can do for $

    Tim
    Winter Park, CO & Lenexa, KS
  • TahoeJohn
    TahoeJohn Member Posts: 20
    I bought a cheap TDS meter and measured our tap water to be 28 ppm.

    I've ordered three units of the Fernox Express F3 cleaner. Once those are here, I will flush the system with fresh tap water and install the F3 cleaner, running it at temperature for 1 week. After that I'll flush with tap water.

    With a TDS of just 28, I'm wondering if I need to use a PuroPal to fill the system, or if I should simply leave it with tap water and install the Fernox Express F1 protector. Thoughts? I read in Idronics #18 that the ideal range for TDS is between 10 and 30.

    In any case, I'll monitor pH over time and shoot for the 8 to 9.5 range, taking action if it's not getting there on its own.

  • TahoeJohn
    TahoeJohn Member Posts: 20
    I'd like to revisit this thread with an update.

    A year ago, I cleaned the system with Fernox Express F3, then flushed thoroughly with tap water and installed three bottles of Fernox Express F1 protector.

    I've just measured the system water:
    pH: 7.03
    TDS: 323 ppm
    Conductivity: 646 us/cm

    And I've remeasured my tap water:
    pH: 7.58
    TDS: 24 ppm
    Conductivity: 48 us/cm

    I'm not very happy with those numbers and am now trying to formulate a new plan. I'm thinking that I should have better listened to Derheatmeister and installed a SorbOx or HWR 15. I've read about good results from using the SorbOx, and have e-mailed Roger Conarroe regarding availability here in the US.

    I also called Low Energy Systems with some questions about the Magnetic Online products and they referred me to Heatmeister, whom I'm guessing is also Derheatmeister here on the forum. Small world.

    Open to any and all suggestions as I continue my learning process here...


  • hot_rod
    hot_rod Member Posts: 18,224
    when you when you add chemicals to the water, expect the TDS / conductivity to go up its reading the stuff you put into the system.

    Did you use the Fernox test kit?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • TahoeJohn
    TahoeJohn Member Posts: 20
    hot_rod said:

    Did you use the Fernox test kit?

    I did not. I have a couple of simple handheld testers, one for pH and one for TDS/conductivity.

    I'm mostly concerned about pH at this point and the fact that it hasn't risen over time. I'd like it to be up in the 8-9.5 range, I believe. Both the SorbOx and the HWR have an anode function that seems to help this, or at least that's how I'm interpreting some of their benefits.