Z flex pipe clearance?

HELP. I need to know the clearance for a Z flex vent on a Clare high boy direct vent oil furnace. OHB5 1998 s/n 182446 85.000 btu. When I inspected the furnace the unit had not been on for over half and hour and the outside temp of the vent pipe was 130.
I told my client it was to close to combustables and he called in the furnace installer and he said it was ok and that it passed inspection. Now my client wants me to pay for the Furnace Company Inspection. ( a few hundred bucks) He is also considering suing me for undue stress.
The vent was within 2 in. of the wood floor and floor joist and the plastic intake air vent was leaning against it. There was also a live wire laying on top of it. All the A/C lines were within one inch. Tks Tim


I’m having a hard time visualizing your conditions. Hopefully you have pictures, if not, I recommend you go back to get some before having to go to court. Hopefully Court won’t occur, but today, you just never know.
I rarely see “Oil systems” in my region, but clearances should still be the same as for NG or LPG, especially if the vent material is rated for Oil,NG,LPG usage.
I’ll be interested to see what you and others find.

Tim, you might find the info here: or at least a number to call.


Good luck.

Cat. III Z-flex requires 1" clearance minimum.

Here are my pictures. Hope they come through.


Looks to me like your pictures are indicating a clearance problem.

I’d call a local inspection official, and discuss what you saw, seeking his/her advice. You can’t bring them in at this point to inspect, but at least you’re on record as to investigating your position/advice you gave to your previous client. If something does come up, you might have witness’ you can call.

By the way, I don’t think I would pay the HVAC Contr. inspection fee. As for your previous clients “undue stress”…give me a break.

Let me get this right. The client called back the guy that installed it wrong in the first place, who claims it is right, and that is passed some sort of “inspection”. Now he wants you to pay for that?

I think I would say, that’s a difference of opinion, and when there are additional problems in the future (like a fire) be sure to call that installer back to fix it.

Tim, what does the manufacturers instructions read, they should be near or at the furnace.

Tim I am not up on Z-Flex but I was wondering if there is some sort of duct connecting devise under the foil tape, it looks like 2 ends butted together to me. I am just asking for my eyes sake, thank you

Can Tim tell us what is going on in this pick?

I’m not seeing something right because I see:
straw at the bottom,
more than one size of Z flex taped together with shiny tape :slight_smile:
and a PVC line into a Z FLEX T.

Are my eyes failing me?

It just is doesn’t look right.


Was the guy who installed it the same guy who inspected it?

Thank you for your interest. The bottom of the picture is the pipe going out the side of the building. There was a live romex wire laying on the top of the flu during inspection. The a/c lines are approx. one inch away as well. It looks as if the flu has been cut and taped togther,using 2 old pieces instead of one complete new one–to save money is my guess. I am sure that is not allowed. How would they connect it inside and also it should be a proper sleeve connection. I think the straw is an old plant or flower arrangement. ??? Also the pvc is touching the flu at one point near the furnace. any comments would be welcome

**Its hard to see the whole picture in your pictures. Direct vent appliances have unique venting. This link may explain what we can’t see. **

**http://yaunco.com/ycreport/july99noframe/clare.html **
Optional DC2000 Direct Venting:
· Stainless steel terminal uses integrated exhaust and outside combustion air format (patent pending).
· Vent or intake blockage safety shutdown design (patent pending).
· Vent lengths up to 30’.
· Zero clearance vent system incorporates stainless steel core and flexible aluminum outer shell separated by 5/8" high temperature fibreglass insulation.
· Rated for wind conditions in excess of 60mph.
· Combustion air piping (field provided) approved for schedule 40; PVC DWV, ABS DWV and ASTMD2729.

http://www.novaflex.com/information_centre/zflex/01Z-Vent%20Residential/Z-Vent_Residential_Installation_Guide.pdf this explains in an enclosed space 8" and in and open space 1"