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tankless coil repairs...

bob youngbob young Posts: 2,177Member
IF it has been leaking a long time , the boiler casting could be rotted. once you proceed there might be a point of no return & ....boiler time. be prepared.


  • kpc_60kpc_60 Posts: 1Member
    what is...

    the best way to go about replacing a tankless coil when you know for sure that the bolts will not come out clean... I have never had to drill out the bolts...what is the best way to core and tap? ty. kpc
  • bob youngbob young Posts: 2,177Member
    drill & tap

    snap them off & just redrill & tap same EXACT size. start w/ center punch & pilot bit. make sure drill bit is exact size to match up with tap. first heat with torch & spray w/ wd 40 they just may come out intact.
  • Bob ForandBob Forand Posts: 305Member
    Oxy/Ace torch

    Kevin, I purchased a small oxy/ace torch kit for that very reason. Heat them up cherry red and they come out fairly easy. The last one I did was a Peerless, I lost two to the other side but four of them came out without a hitch. It beats the aggravation.
  • Charlie from wmassCharlie from wmass Posts: 4,070Member

    Try PB blaster for frozen bolts. smells like bug killer but works very well. I shudder when I think of taking out tankless heaters as when I was 18 I had one that went very wrong. Came out smelling like roses in the "Sure Missus I can fix it for you, no problem half a day at the most"
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • kpc_61kpc_61 Posts: 1Member

    this has to be the worst coil I have ever seen. it is a Utica starfire 3100. It is 20-25 years old...and has been leaking for at least 10 very slowly. I can't even see the bolt heads they are so corroded... I am possibly talking them into a new unit but I don't want to try to repair something and have them be out of heat and hot water....ty
  • Charlie from wmassCharlie from wmass Posts: 4,070Member

    It may have brass nuts being a utic. this would be a good thing. I am not sure when they started using brass nuts again though. Good luck. a new unit would be money better spent, but budgets are tight. of course new on their dime is better than new on your dime too.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • realolmanrealolman Posts: 513Member
    never used it myself

    but there are guys in the shop who say the spray to freeze stuff works real well. I believe loctite makes it.

    The very best way to get out a broken bolt is to not break it in the first place.... but then you knew that

    I'd say , soak it with wd 40 or pb blaster, beat it with a hammer to get it's attention and cause the wd 40 to soak it, spray it again, try to turn it both directions a little,try the freeze spray, heat it.

    good luck
  • I heat

    them up re hot with my soldering tourch, then if they break use those good german channel locks with slanted teeth, they grip unbelievably well.

    Thanks, Bob Gagnon

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  • Hank_5Hank_5 Posts: 16Member

    I've replaced more coils than I care to count. I've found that spraying with PB Blaster can help, sure doesn't hurt. But, bolts may still snap. I center punch and start with a small bit and work up a size at a time. You can watch for threads to show up then stop. From there I use an awl, tapping gently with my hammer to pry out the rest of the bolt. It's never failed me. Then chase the threads.

    I use high quality bits for the job. Found that EZ outs seldom work. Broke one once. Made more work for myself.
  • rene_4rene_4 Posts: 27Member

    I've tried quite a few penetrating fluids ove rtyears and I've found hat WD 40 doen't work that good. The WD stands for Water Displaced therefore it's good for dispersing water like in wiring etc. great for old spark plug wires. The best stuff I've found is called Aero Kroil. Let that soak overnight and spray again the next day and they should back out. If you can use heat, obviously that's the best.
  • oil-2-4-6-gasoil-2-4-6-gas Posts: 641Member

    WD-40 is great for putting a shine on -but worthless for penetrating ---PB-blaster,Liquid Wrench --Super Penetrant (in small squeeze bottle) -Aero-Kroil are what you need --90% of the coils i worked on bolts broke --now i just cut the heads off flush with the coil plate --use a small pipe wrnech to remove --or weld onto the leftover bolt -- PUT NEVERsieze on the new fasteners
  • kpc_64kpc_64 Posts: 2Member
    what do ...

    you use to cut off the bolts? Neversieze is a must. In fact when I do new boilers and they have coils(rare these days)I pull outnthe bolts and stick them back in w/ neversieze....great stuff.
  • bob youngbob young Posts: 2,177Member

  • kpc_65kpc_65 Posts: 1Member
    i understand..

    what could be used. I was interested in what he used.
  • mike parnellmike parnell Posts: 42Member
    broken bolts

    I think the p-b stuff works great, but what ive found is to use left handed drill bits,most times in the process of drilling them out the drill grabs and twists them right out,on a good day,some days not so good,its worth the chance,Ive just noticed my own boiler three years old is leaking at the gasket going to have to change it this summer,lots of never seize will be used.........good luck.
  • Mike C._4Mike C._4 Posts: 56Member
    Let's get them out

    If you can get a good grip on the bolt heads-get some bees wax. Heat the bolt and around (dull red or so) it and press the wax around the threads. The wax will melt deep into the threads. Alternately tighten and loosen the bolt until it the bolt feel free enough to come out. The stuff smokes but it isn't too noxious. PB blaster is great for a first try. You can still use the wax with drilling and an easy out. Just use patience. Been doing this for years on steam systems.

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