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takagi TK-3 ZFlex concentric vent replacement

Installed and working unit, removed some siding and the outer vent that slides into the "thimble", chasing what appeared to be a wet spot directly under and to the side of the vent. Turned out not to be there, but apparently poor weatherproofing elsewhere.

In any event, now the vent refused to play nice and slide into place. Pretty tight fit, with two gaskets/seals to get past. Short story, not good. Tore up the inside, white flat ribbed seal. Takagi does not sell that separately so had to buy the assembly, but, thankfully not the complete kit. Still around $100 all told.

What am I here for? How to re-install with least hassle. Been years since I installed it, but recall it seemed impossible to get all the venting assembled without dropping the heater a couple inches to get al the joints to fit properly. A two man job.

Maybe there is an easier way? The new parts are the hood vent and concentric pipe, the interior mating piece and slip fit, with the 3 inch air and 4 inch exhaust ports.

Comments

  • Larry Weingarten
    Larry Weingarten Member Posts: 2,363
    Hi, Could you get us some photos, both close and far? I'm pretty sure that would help us give you useful responses. ;)

    Yours, Larry
  • joea99
    joea99 Member Posts: 29
    Sure, hope these help. Thinking I can drop the unit a couple inches, even if I have to break the propane union to do so. There is corrugated thin wall, forget the name, coming from above. Pex connects the water lines.






  • Larry Weingarten
    Larry Weingarten Member Posts: 2,363
    Hi, That's corrugated stainless steel tubing (CSST) supplying the heater. If you have, or can borrow an automotive floor jack (or even bottle jack), perhaps you could use it with some 2X4 up to the heater to support it and lower the heater down in a controlled manner. It would be nice to have a helper, but strapping the heater so it couldn't tip over could make this a one person job.

    Yours, Larry
  • joea99
    joea99 Member Posts: 29
    edited November 2021

    Hi, That's corrugated stainless steel tubing (CSST) supplying the heater. If you have, or can borrow an automotive floor jack (or even bottle jack), perhaps you could use it with some 2X4 up to the heater to support it and lower the heater down in a controlled manner. It would be nice to have a helper, but strapping the heater so it couldn't tip over could make this a one person job.

    Yours, Larry

    Thanks. I was just taking a break from doing exactly that, after isolating the water and gas supply. I am working solo so the strapping idea might be wise, but the pex, etc, might be enough to keep it reasonably safe from tipping over. Gotta go fight two reluctant blue self drilling masonry screws the Dewalt impact won't move.

    Darn shame Takagi does not sell the seal alone. Apparently. The old was was showing deterioration, maybe that is what made it easy to "roll" the edge up. The new one seems different in ridges and material, comes "pre lubed". While I was thinking I was stupid to remove the vent, maybe in the long run its for the best.
  • joea99
    joea99 Member Posts: 29
    edited November 2021
    joea99 said:


    Darn shame Takagi does not sell the seal alone. Apparently. The old was was showing deterioration, maybe that is what made it easy to "roll" the edge up. The new one seems different in ridges and material, comes "pre lubed". While I was thinking I was stupid to remove the vent, maybe in the long run its for the best.

    Turns out Z-Vent/NovaFlex (whatever) DOES offer the gaskets. But, there are two versions, the "old" and the "new". One is about 3/8 wide the original about 1/2 wide. The groove they sit in are of corresponding width, so "should not be interchanged". 0GSKT04 and 0GSKT04OG (for "old gasket"). Good luck finding a supplier that will special order them. Luckily the manufacturer has great customer service.

    According to their tech, the gaskets can deteriorate from the effects of hydrochloric acid over the years but will continue to act as an adequate seal, for the most part, until disassembled.

    I will also ease any future maintenance issues by replacing one of the vent pipes with a length adjustable unit, probably Z-flex part number 2SVSALM4. Wish I knew about those when I installed this. Maybe I did and was just too cheap to spring for it. I can be like that.
    Larry Weingarten