Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

CENTROTHERM for KHN 085 Boiler

Options
keyote
keyote Member Posts: 659
Dont want to use PVs at least not for exhaust anyone know where to find this stuff preferably online otherwise brooklyn ny its 2'' tap Im going sidwall

Comments

  • SWEI
    SWEI Member Posts: 7,356
    Options
    Shipping lengths of low weight pipe in small quantities makes little economic sense. http://www.ratheassociates.com/ covers your area and should be able to point you at a stocking wholesaler.
    Rich_49
  • keyote
    keyote Member Posts: 659
    edited September 2016
    Options
    Thanks swei , think i need to do fresh air in poly also i have a PVC pipe already in from the TT

    have you done KHN ,it came with a piece that has a threaded tap i guess for testing flue gas but the piece doesnt fit the boiler stubs, both male
  • SWEI
    SWEI Member Posts: 7,356
    Options
    We use cell-core PVC for fresh air probably 90% of the time.

    No real distribution support for Lochinvar in our part of the state, so no KHN's yet.
    TinmanRich_49
  • Boon
    Boon Member Posts: 260
    Options
    Keyote, I had trouble sourcing polypropylene venting parts, too. Eventually I found the CPVC ASTM F441 (IPEX) at Ferguson, which can be used instead of the polypropylene. Nothing in the manual prohibits PVC for fresh air as long as it meets the standards on Pg 19.

    If I remember correctly, both Centrotherm and PolyPro had steeper slope requirements than CPVC and PVC. I don't know why, but it was another variable that made using CPVC easier for me.
    DIY'er ... ripped out a perfectly good forced-air furnace and replaced it with hot water & radiators.
  • keyote
    keyote Member Posts: 659
    Options
    thanks boon found centrotherm online pretty cheap mine is almost 45 degrees straight out of boiler then 45 more after through side wall no biggie plumb supply has a no name poly as well also cheap.I am going to have to track dowwn a thread on here i saw once about the first fitting to connect the boiler and the test port pc to the flue
  • R Mannino
    R Mannino Member Posts: 440
    Options
    AF Supply stocks Centrotherm
  • Boon
    Boon Member Posts: 260
    Options
    The first fitting needs to be a centrotherm appliance adapter, clamp, and connector their part numbers are on Pg 20. I found places online that had centrotherm but none had the adapters in stock.

    Then get a centrotherm test port to replace the factory supplied one. http://www.centrotherm.us.com/products/single-wall-residential/system-components/test-ports/
    DIY'er ... ripped out a perfectly good forced-air furnace and replaced it with hot water & radiators.
  • keyote
    keyote Member Posts: 659
    edited October 2016
    Options
    thanks boon I saw that centro therm w test port and had that thought so are you saying you were able to put that centro therm directly on the boiler?
    BTW it seemed to me there are several types of centrotherm but that we want the single wall inoflue was that you take

  • keyote
    keyote Member Posts: 659
    Options
    Thanks Manny I do use af sometimes though they insist i drive over before answering most questions.
  • Boon
    Boon Member Posts: 260
    Options
    are you saying you were able to put that centro therm directly on the boiler?

    I didn't use it, but yes. The Centrotherm appliance adapter (#ISAGL0202) will transition from the boiler's 2" fitting to the Centrotherm vent system. Using Centrotherm, you might also need the adapter clamp (#IAFC02) & joint connector (#IANS02) but it wasn't (still isn't) clear to me, which leads to the other reason why I used CPVC instead: I understand and have experience with solvent welds so CPVC was the safer option for me.

    And I'll risk offending you by reminding you to be mindful about getting shavings into the vent system. I used a shop-vac to get shavings out of the pipe before installing and I still got a few shavings in the burner.
    DIY'er ... ripped out a perfectly good forced-air furnace and replaced it with hot water & radiators.
  • gennady
    gennady Member Posts: 839
    edited October 2016
    Options
    try american universal , long island. ask for charlie. they can get you centrotherm or equal duravent cpvc venting next day delivery.
  • keyote
    keyote Member Posts: 659
    Options
    thanks boon,gennady
  • JUGHNE
    JUGHNE Member Posts: 11,075
    Options
    Has there been any catastrophic failures of SCH 40 PVC used for condensing appliances? I know there are local regs and code requirements for some areas that prohibit it.

    I have some 30+ year old condensing FAF and boilers that are still running. Have heard of no failures with the venting. Of course if I were to change these out I would replace the existing old PVC venting with new PVC according to the I&O manual.

    In my area there is no enforcement or requirements other than the installation manual.....and there have been installations by others that the manual is ignored.

    I was involved in the recall/change out for the "UltraVent" material of 20 some years ago.
    Are we looking at something as major as that in the ModCon/cond FAF industry in the future???
  • hot_rod
    hot_rod Member Posts: 22,256
    Options
    JUGHNE said:

    Has there been any catastrophic failures of SCH 40 PVC used for condensing appliances? I know there are local regs and code requirements for some areas that prohibit it.

    I have some 30+ year old condensing FAF and boilers that are still running. Have heard of no failures with the venting. Of course if I were to change these out I would replace the existing old PVC venting with new PVC according to the I&O manual.

    In my area there is no enforcement or requirements other than the installation manual.....and there have been installations by others that the manual is ignored.

    I was involved in the recall/change out for the "UltraVent" material of 20 some years ago.
    Are we looking at something as major as that in the ModCon/cond FAF industry in the future???

    I think the boilers that run high operating temperatures will be the first to show problems. PVC that goes from bright white to yellow in a few years time must be going through some change.

    Is either PVC or CPVC rated for 180F or higher temperatures?




    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    Tinman
  • JUGHNE
    JUGHNE Member Posts: 11,075
    Options
    Yes, I see the difference. The exhaust pipe looks like PVC that has laid out in the sun for 10 years. That must be running pretty hot most of the time.

    However, from what I have read here of other posts, the PVC companies offer no temp guidelines and some have said they do not approve the use of their product for venting.

    But do most manufactures approve the use of PVC in their I&O manuals? So sometime in the future when brittle PVC shatters and there is an incident of CO poisoning who will be called on the carpet?

    PVC companies can say "we told you so".
    Installers said "we followed the I&O".
    Manf will say "we have tested this and the pipe/install must have faulty".
    Lawyers will say we are suing all of the above, including the NG company for selling a dangerous flammable product.....also the horses we all rode in on.
    We all know the drill.
  • keyote
    keyote Member Posts: 659
    Options
    Jug I just bought the KHn and somewhere on here came upon a thread or two that indicated the problem with PVC is really so much the flue failure but that theres an interaction of the condensates and pvc that is not great for the heat exchangers , obviously this is new knowledge and most modcons are pvc vented cat say how serious but didnt want to mess with new bpoiler since this centrotherm is no more expenve than pvc fittings
  • kcopp
    kcopp Member Posts: 4,443
    Options
    I am in New Hampshire and the state Fire Marshall has all but outlawed pvc use. There are so many hoops to jump through to ok it s use. Mostly they want the boiler or Water heater to have the unit shut down if the flue temp goes over 140F. And they want to see the documentation .
    They are even questioning Poly Pro if the boiler flue temps can go over 230F... I guess some of the Lochinvar units don't shut off until 250F...thus you need to go SS.

    The Dura vent poly pro should be pitched 1/2' to 5/8" per foot lest the gaskets start to leak.

    I did recently saw a PV water heater that the 2" was all but light purple and had a huge dip in it. Water heater was still in use.

    I guess bottom line all venting oil ,gas, wood needs to be checked on a regular basis.
  • JUGHNE
    JUGHNE Member Posts: 11,075
    Options
    Keyote, could the condensate be leaching the PVC out to produce the "coffee grounds" so common in water tube boilers?

    The "coffee grounds" I have removed would stick to a magnet though.

    Are the "coffee grounds" a problem with SS venting or the polypropylene?? Or is it too early to tell with the later?
  • keyote
    keyote Member Posts: 659
    Options
    jugh
    Kcopp brings another dimension to this i have not heard about.Interestingly i used concentric SS for my tankless water heaters but that gets quite spendy and difficult [and i am a tinknocker by trade] This boiler only has a short run basically 45 degrees up and through the wall so it a short steep run.
    as i recall its chlorides that leech into the heat exchanger now they might tear off some of the stainless but honestly i was acting only an a vaugue memory and cant find the source now can only say several pros chimed in that poly was the way to go these days i know one issue is a ppan at the bottom that some boilers now make in plastic instead of metal post back if you find the deal out
  • JUGHNE
    JUGHNE Member Posts: 11,075
    Options
    It was just a thought I had as the "grounds" are blamed on a lot of things.
    Perhaps a Tee trap just as exhaust exits the boiler, that would catch most of the long run pipe condensation keeping it out of the heat exchanger??

    The FAF I install have a T trap right on the exit and most of the pipe condensate goes there to avoid the fan from flooding.
  • rick in Alaska
    rick in Alaska Member Posts: 1,457
    Options
    The khn is a firetube boiler, and the exhaust comes out of a cpvc pipe from the bottom of the boiler condensate collector. So, any chlorides leaching form the pvc should just drop straight down the cpvc pipe and land in the condensate collector, and not touch the heat exchanger at all.
    I don't see the problem with chlorides myself.
    Rick
  • keyote
    keyote Member Posts: 659
    edited October 2016
    Options
    Thanks ricks its been dawning on me I must have misinterpreted something because i have since read a couple threads saying what you just said, although they seem to indicate that the collector on some boiler is integral to heat exchanger and some are now made of different materials. I could have sworn though lol. so i guess somehow? the condensation happens on the way out of the heat exchanger but the flue is connected in such a way the condensate running back is diverted? but why all the hysteria about PVC flues?

    ok re reading your comment I see you say the flue conects down in the collector so the condensate cant flow up into HX, i guess since its fan driven that works
  • Tinman
    Tinman Member Posts: 2,808
    Options
    I don't think there's any hysteria at all about PVC flue on boilers. It's real and it should not be used anywhere near the boiler in my opinion. At least, run 4'-6' of cpvc from the outlet of the boiler to allow the flue gas to cool a bit. I see the discoloration and actually warping of well supported horizontal runs all the time on boilers. Rarely see it on furnaces.
    Steve Minnich
  • keyote
    keyote Member Posts: 659
    Options
    until this thread i never read any concerns about temp all the threads i read about Centro therm seemed concerned with chlorides.I wish i had known this is would have considered stainless again but ive gone from pvc to Centro therm both recommended in manual i cant rip it out again unless i see some damage occurring. as i said my run is basically a 3' piece at a 45 degrees angle through a window opening then a 45 with a short extension, of course thats the hotest part of the run, i think centrotherm is working for many since they praise it