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Time for cleaning of HTP modcon

Suzook
Suzook Member Posts: 221
So its year 3, and based on my water here, i need to flush the HX on my modcon boiler.. Im getting different opinions on what to use. Seems like White vinegar should do the job. Run it though it for an hour, or 2. Thoughts? Thanks

Comments

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,421
    edited November 2020
    Look in the installation and operation manual that came with the unit. it may say something like this:

    C. Cleaning Water Side of Heat Exchanger
    1. Make sure power is
    turned off to the boiler.
    Run water through the
    hot water system to
    ensure it is below room
    temperature.
    2. Close isolation valves
    on the return and supply
    connections to the
    boilers as shown in the
    piping diagrams in this
    manual. Slowly open the
    ball valves and release
    pressure into a bucket.
    Once pressure is released,
    connect a hose to the
    water line to flush the
    boiler. Scale removing
    solution may be used
    , but
    must be approved for use
    with stainless steel and
    FDA approved for use in a
    potable water system.
    3. Thoroughly flush the
    heat exchanger before
    commissioning the unit
    back in service.


    Vinegar is an acceptable solution, there are also commercially available products specifically designed for this procedure. I carried 1gallon bottles of vinegar on my service truck so I could flush a system if a customer requested it while I was there for something else. You know... "since you are already here, how much to service the water heater?" I would be prepared to say "Yes, it will cost $$$"

    But usually, I would bring the commercially available chemical if the job was scheduled to be Maintained and it included a Flush.

    The vinegar was also on the truck for those small oil spills made during a service call, when the customer was especially sensitive to the oil odor. I would tell them that vinegar would help cut the oil odor. (Then add... If I had a clove of garlic, I could make it smell like a Cesar Salad) ...True story.... I always liked to add those extra little tidbits for the customers amusement... Like ..."I hate to heat and run... but other customers are cold!"
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
    motoguy128unclejohn
  • Suzook
    Suzook Member Posts: 221
    Thats EXACTLY what it says, so im guessing vinegar should do the trick, without harm. Thanks
    EdTheHeaterMan
  • Ironman
    Ironman Member Posts: 6,600
     What model HTP?
     Why do you think that you need to flush a closed loop system after 3 years? Or, is this a combi and you’re referring to the domestic side?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    mattmia2Zman
  • Suzook
    Suzook Member Posts: 221
    edited November 2020
    Ironman said:

     What model HTP?
     Why do you think that you need to flush a closed loop system after 3 years? Or, is this a combi and you’re referring to the domestic side?

    It a htp uft-80, it calls for flushing the hx. Based on my water here, I should do it every 3 to 4 years. But now that I'm looking, I don't have a way to isolate the hw side with a shutoff valve. Gonna have to sweat one in. Ugh

    There's an old pic
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 2,421
    A work of ART.

    I'm talking about the brownish wall with the white artwork on it.

    I think the drywall taper was named Art
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
    Solid_Fuel_Man
  • Ironman
    Ironman Member Posts: 6,600
    Well, the I/O manual actually says once a year, but that’s hogwash. The only way that the heat exchanger can have a scale buildup would be if there are leaks on the system which are causing fresh water with fresh minerals to be added regularly. As long as there are no leaks, there are minerals being added to require de-scaling.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    HomerJSmith
  • Suzook
    Suzook Member Posts: 221

    A work of ART.

    I'm talking about the brownish wall with the white artwork on it.

    I think the drywall taper was named Art

    Lol, it's in my garage. I sorta thought about properly taping it and paint, but it would then be better than the rest of the garage.
  • SuperTech
    SuperTech Member Posts: 1,691
    The way that expansion tank is installed would make me nervous. If that tank fails and becomes waterlogged its going to put a lot of weight on the piping. I'd support it with some threaded rods and kindorff....but then again that is an old picture. 
    Canuckerunclejohnmattmia2BDR529
  • Suzook
    Suzook Member Posts: 221
    Ironman said:

    Well, the I/O manual actually says once a year, but that’s hogwash. The only way that the heat exchanger can have a scale buildup would be if there are leaks on the system which are causing fresh water with fresh minerals to be added regularly. As long as there are no leaks, there are minerals being added to require de-scaling.

    Manual actually says 2 to 3 years for my water levels here where I live. I believe I have no leaks, but with copper buried in slab, it's a possibility. I figured for an hour of my time, why not do it?
  • Suzook
    Suzook Member Posts: 221
    SuperTech said:

    The way that expansion tank is installed would make me nervous. If that tank fails and becomes waterlogged its going to put a lot of weight on the piping. I'd support it with some threaded rods and kindorff....but then again that is an old picture. 

    Yes, old pic during install, I should have noted it's now supported.
    SuperTech
  • SuperTech
    SuperTech Member Posts: 1,691
    My opinion is that you should go for it.  It won't hurt to run some vinegar through it. It couldn't hurt.
    Suzook
  • Suzook
    Suzook Member Posts: 221
    I have a way to go in and out the heat exchanger using the bottom of boiler., but up top in pic, you can see I have shutoffs on return, but on the feed for heat where the circ pump is, no way to shut it off. I'm assuming if I try to pump through the bottom, it would also pump through that circ pump? Hence I NEED A shutoff on that side? Thanks again.
  • 660grizzlyguy
    660grizzlyguy Member Posts: 2
    Is the circulator on the correct side of the air eliminator? If you are going to add a valve, maybe think about redoing that as well.
  • Suzook
    Suzook Member Posts: 221

    Is the circulator on the correct side of the air eliminator? If you are going to add a valve, maybe think about redoing that as well.

    Technically it's not, but don't want to open that can of worms. Just looking to sweat in a shutoff right after it. System working fine the way it's set up. So I'm assuming a shut off is needed on that end?
  • hot_rod
    hot_rod Member Posts: 15,066
    Actually You add more scaling minerals after you do the cleaning. Check the fill water quality, hardness, TDS if you can. If it was filled with good quality water, I would let it be.
    If anything add a hydronic conditioner product like Rhomar. That will balance Ph, scavenge O2 protect the metals.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    IronmanHomerJSmith
  • Suzook
    Suzook Member Posts: 221
    hot_rod said:

    Actually You add more scaling minerals after you do the cleaning. Check the fill water quality, hardness, TDS if you can. If it was filled with good quality water, I would let it be.
    If anything add a hydronic conditioner product like Rhomar. That will balance Ph, scavenge O2 protect the metals.

    Tds is 130, hardness70. Thoughts?
  • HomerJSmith
    HomerJSmith Member Posts: 1,380
    edited November 2020
    Why in hades aren't you using conditioned water in your sys?

    Find a ceiling joist and support that X-tank, for pete sake.

    Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.
  • Suzook
    Suzook Member Posts: 221
    edited November 2020

    Why in hades aren't you using conditioned water in your sys?

    Find a ceiling joist and support that X-tank, for pete sake.

    Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.

    Well....I corrected the post and stated, its an old pic during install. Tanks IS supported. And why am i not using conditioned water? I figured i would be fine with a simple flushing of HX every 2 or 3 years. I guess everyone has an opinion. Im also thinking of doing a complete flush, then a refill, and then a treatment with Rhomar. Thoughts? Thanks again everyone.
  • Canucker
    Canucker Member Posts: 703
    Suzook said:
    Why in hades aren't you using conditioned water in your sys? Find a ceiling joist and support that X-tank, for pete sake. Send a water sample to Rhomar for testing before you commence with the cleaning. The cost may be worth it and you will learn something about your sys.
    Well....I corrected the post and stated, its an old pic during install. Tanks IS supported. And why am i not using conditioned water? I figured i would be fine with a simple flushing of HX every 2 or 3 years. I guess everyone has an opinion. Im also thinking of doing a complete flush, then a refill, and then a treatment with Rhomar. Thoughts? Thanks again everyone.
    Absolutely do that. Fill it with demineralised water, add the chemical treatment and you probably won't have to do much other than test the levels for a number of years. Unless you get a leak, obviously.
    You can have it good, fast or cheap. Pick two
    fenkel
  • Suzook
    Suzook Member Posts: 221
    Well I was gonna do a refill of my tap water after flushing, then add rohmar.
  • fenkel
    fenkel Member Posts: 135
    Rohmar recommends either deminerized  or deionized water..
    They claim both work well with their chemicals..
  • Suzook
    Suzook Member Posts: 221
    Sort of a funny story. As this thread is goin on, my buddy who is a plumber, had a callout for this exact same boiler. Kept throwing codes, and shutting off. What was going on was the inside of HX needed to be cleaned. Vacuumed out, and cleaned. Said after 3 years it was pretty dirty. Guess i will be adding that to the list. HE said on this boiler its a bit of a pita.
  • Suzook
    Suzook Member Posts: 221

    I vacuumed out the inside of hx. Wasn't too bad. Just need to flush out the inside this weekend.


  • Ironman
    Ironman Member Posts: 6,600
    That HX needs more than vacuuming.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Suzook
    Suzook Member Posts: 221
    edited November 2020
    Not sure what happened to my post. I cleaned it with water, and a stiff bristle brush. Then vacuumed.
  • mattmia2
    mattmia2 Member Posts: 4,008
    So what is the service for these? I've been meaning to ask. The maintenance section of the manual seems to have been copied from a water tube tankles water heater.
  • Suzook
    Suzook Member Posts: 221
    mattmia2 said:

    So what is the service for these? I've been meaning to ask. The maintenance section of the manual seems to have been copied from a water tube tankles water heater.

    Same as most ModCons. Flush out water side of HX, clean out fire side of HX, clean condensate trap, check combustion. Its pretty simple. It is odd that HTP doesn't mention cleaning out the fire side. I guess they "assume" the design of the fire tube somehow miraculously cleans itself. 2 hrs of time, every few years, is worth doing it.
  • mattmia2
    mattmia2 Member Posts: 4,008
    Yeah, the fire side is what I don't know how to do, especially with those fins. The water side I really don't see getting fouled up in a sealed system with modern emitters.
  • Suzook
    Suzook Member Posts: 221
    mattmia2 said:

    Yeah, the fire side is what I don't know how to do, especially with those fins. The water side I really don't see getting fouled up in a sealed system with modern emitters.

    Mine were just gunked up on top, as seen in the pic. A stiff bristle brush with water worked for me. Some use clr, or vinegar. I guess if left neglected it would get bad further down the tubes, and you would have issues getting them clean.
  • mattmia2
    mattmia2 Member Posts: 4,008
    I'm not super excited about everything being on the pressure side of that blower from the mixed air/fuel to the products of combustion especially with a lot of difficult to inspect/verify o-ring and flange type joints.
  • Suzook
    Suzook Member Posts: 221
    Well every boiler seems to have it's pluses and cons. Like stated, it's very easy to work on. I believe with propper maintenance, it should last many years. If your that concerned, just clean it annually, that should keep the hx in decent shape.
  • Suzook
    Suzook Member Posts: 221
    So I flushed hx yesterday, and there definitely was some gunk. So a freshly cleaned fire side, and water side now. Guess I will do this every 2 years. Pretty simple, maybe 2 hrs total time. Tomorrow, I will double check combustion, make sure it's still good.