# Flexible Gas Pipe Through Metal Furnace with Protective Connectoe **URL:** \ **Category:** Misc. Discussion\ **Created:** [April 18, 2022, 8:28pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615 "2022-04-18T20:28:41Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![chall20](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/chall20/32/180613_2.png) [@chall20](https://forum.nachi.org/u/chall20)\ **Post date:** [April 18, 2022, 8:28pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/1 "2022-04-18T20:28:41Z")
I have never heard of a grommet/bushint/protective measure for gas piping through metal furnace wall. The furnace had a mild vibration the pipe felt secure. Is this allowed? ![IMG-2004](https://global.discourse-cdn.com/internachi/original/3X/3/e/3edacdafdd513632fec2f1cb54906543402d776f.jpeg) ---
**Author:** ![mwilles](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mwilles/32/181480_2.png) [@mwilles](https://forum.nachi.org/u/mwilles)\ **Post date:** [April 18, 2022, 8:34pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/2 "2022-04-18T20:34:39Z")
This appliance connector appears to be properly installed. It is protected from damage if the air handler was to vibrate. ---
**Author:** ![tglaze](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/tglaze/32/362210_2.png) [@tglaze](https://forum.nachi.org/u/tglaze)\ **Post date:** [April 18, 2022, 8:39pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/3 "2022-04-18T20:39:49Z")
Martin, what type of flex line is that? I’ve haven’t come across it yet. TIA! ---
**Author:** ![mwilles](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mwilles/32/181480_2.png) [@mwilles](https://forum.nachi.org/u/mwilles)\ **Post date:** [April 18, 2022, 8:42pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/4 "2022-04-18T20:42:53Z")
It’s just a stainless steel appliance connector. ---
**Author:** ![tglaze](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/tglaze/32/362210_2.png) [@tglaze](https://forum.nachi.org/u/tglaze)\ **Post date:** [April 18, 2022, 8:54pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/5 "2022-04-18T20:54:42Z")
Thanks! In my area, maybe 2 out 10 inspections have gas fueled furnaces and less for WH’s. Mainly because the vast majority of homes are propane if they choose to go that route. Usually, the ones I see are either black steel/iron piped, or the yellow CSST style flex. Haven’t come across a stainless yet, but glad I asked. Saves me time from asking again. 😉 ---
**Author:** ![mwilles](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mwilles/32/181480_2.png) [@mwilles](https://forum.nachi.org/u/mwilles)\ **Post date:** [April 18, 2022, 8:57pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/6 "2022-04-18T20:57:19Z")
Appliance connectors used to be brass, I haven’t seen those for 30 years. I’ve seen nothing but stainless steel, sometimes the stainless steel appliance connector are painted yellow. ---
**Author:** ![tglaze](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/tglaze/32/362210_2.png) [@tglaze](https://forum.nachi.org/u/tglaze)\ **Post date:** [April 18, 2022, 9:04pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/7 "2022-04-18T21:04:45Z")
Thanks again Martin! And back to the OP’s question, it might depend on your local codes, but the plastic/rubber grommets are sufficient in my area. ---
**Author:** ![chall20](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/chall20/32/180613_2.png) [@chall20](https://forum.nachi.org/u/chall20)\ **Post date:** [April 18, 2022, 9:09pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/8 "2022-04-18T21:09:47Z")
Thanks. I thought it was but had never heard of this. I had always just heard use rigid pipe. ---
**Author:** ![mwilles](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mwilles/32/181480_2.png) [@mwilles](https://forum.nachi.org/u/mwilles)\ **Post date:** [April 18, 2022, 9:17pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/9 "2022-04-18T21:17:23Z")
> [@chall20](#): > > I had always just heard use rigid pipe. That may be something to look into maybe that is what is approved in your area. When I was a plumber in Chicago there were no appliance connectors on furnaces or water heaters everything was solid piped. ---
**Author:** ![dandersen](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dandersen/32/59398_2.png) [@dandersen](https://forum.nachi.org/u/dandersen)\ **Post date:** [April 18, 2022, 10:35pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/10 "2022-04-18T22:35:54Z")
I have only seen SST used around here, but your not here… That (Romex) is required to be in conduit around here too. ---
**Author:** ![chall20](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/chall20/32/180613_2.png) [@chall20](https://forum.nachi.org/u/chall20)\ **Post date:** [April 18, 2022, 11:12pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/11 "2022-04-18T23:12:29Z")
That seems odd considering there doesn’t seem to be much consensus on whether that’s right or wrong ---
**Author:** ![tglaze](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/tglaze/32/362210_2.png) [@tglaze](https://forum.nachi.org/u/tglaze)\ **Post date:** [April 18, 2022, 11:19pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/12 "2022-04-18T23:19:37Z")
Pretty sure the consensus is that it’s allowed unless your local jurisdiction says it isn’t. What does your local say? ---
**Author:** ![mfellman](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mfellman/32/369692_2.png) [@mfellman](https://forum.nachi.org/u/mfellman)\ **Post date:** [April 18, 2022, 11:26pm UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/13 "2022-04-18T23:26:11Z")
> [@mwilles](#): > > Appliance connectors used to be brass, I haven’t seen those for 30 years. I always write these up when I see them. Aside from being 30+ years old there were some that disintegrated due to reacting with something in some fuels. In my area (Oregon) it’s common to see bare stainless like the picture or various coated ones that are gray, yellow (NOT CSST) or black. Brass is pretty rare but I’ll still find one or two a year. ---
**Author:** ![dandersen](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dandersen/32/59398_2.png) [@dandersen](https://forum.nachi.org/u/dandersen)\ **Post date:** [April 19, 2022, 1:20am UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/14 "2022-04-19T01:20:27Z")
I checked with six HVAC guys in different states. Not a one says it is OK in their state. You guys know these folks: > **[Everything You Need to Know about Gas Piping - Home Inspection Training](https://www.carsondunlop.com/training/2017/07/11/everything-you-need-to-know-about-gas-piping/)** > > The beginning of October means many homeowners living in the northern part of the country will have to start firing up their heating systems. Natural gas is among the least expensive and most efficient ways to fuel a furnace or boiler. Along with its... > **[HVAC Inspection Guide - InterNACHI House of Horrors](https://www.nachi.org/school/internachi-university/colorado-house-of-horrors/guide/hvac-inspection-guide/)** > > Toggle navigation InterNACHI House of Horrors Home Training In Boulder, CO In Weston, FL Instructors & Mentors Directions While You’re In Colorado House of Horrors® House of Horrors® in CO House of Horrors® in FL Inspection Guide for the CO House... > . CSST should not be confused with flexible gas appliance connectors that join an appliance to the gas supply line of a house. ---
**Author:** ![dwilliams49](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dwilliams49/32/230450_2.png) [@dwilliams49](https://forum.nachi.org/u/dwilliams49)\ **Post date:** [April 19, 2022, 1:40am UTC](https://forum.nachi.org/t/flexible-gas-pipe-through-metal-furnace-with-protective-connectoe/214615/15 "2022-04-19T01:40:26Z")
The natural gas service providers’ technicians will tag it and call you out on it if you don’t use black iron pipe going into the cabinet and gas valve. That’s in most of the metro Atlanta counties, at least.