# Flexible gas appliance connector **URL:** \ **Category:** Inspecting HVAC Systems\ **Created:** [April 9, 2014, 4:33am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963 "2014-04-09T04:33:12Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jreim](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jreim/32/60282_2.png) [@jreim](https://forum.nachi.org/u/jreim)\ **Post date:** [April 9, 2014, 4:33am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/1 "2014-04-09T04:33:12Z")
Looking for an opinion on the use of a flexible gas appliance connector used to supply a furnace. My memory tells me this is not allowed but wanted to check. From the shut off valve to the furnace has to be hard pipe? Lack of sleep not helping my brain… Thanks, ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [April 9, 2014, 6:11am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/2 "2014-04-09T06:11:23Z")
If you ask ten inspectors that question, you may get 12 or 13 opinions. Here’s the current IFGC 2012 > [@](#): > > **SECTION 411 (IFGC)**\*\*\*\* > 411.1 Connecting appliances. \*\*\*\* > Except as required by [Section 411.1.1](http://publicecodes.cyberregs.com/icod/ifgc/2012/icod_ifgc_2012_4_sec011.htm), _appliances_ shall be connected to the _piping_system by one of the following: > > 1. Rigid metallic pipe and fittings. > 2. Corrugated stainless steel tubing (CSST) where installed in accordance with the manufacturer’s instructions. > 3. Semirigid metallic tubing and metallic fittings. Lengths shall not exceed 6 feet (1829 mm) and shall be located entirely in the same room as the _appliance._ Semirigid metallic tubing shall not enter a motor-operated \*appliance \*through an unprotected knockout opening. > 4. \*Listed \*and \*labeled appliance \*connectors in compliance with ANSI Z21.24 and installed in accordance with the manufacturer’s instructions and located entirely in the same room as the _appliance._ > \*\*\*\*411.1.3.3 Prohibited locations and penetrations. \*\*\*\* > Connectors shall not be concealed within, or extended through, walls, floors, partitions, ceilings or _appliance housings. \*\* > Exceptions:_ > 5. Connectors constructed of materials allowed for \*piping \*systems in accordance with[Section 403](http://publicecodes.cyberregs.com/icod/ifgc/2012/icod_ifgc_2012_4_sec011.htm) shall be permitted to pass through walls, floors, partitions and ceilings where installed in accordance with [Section 409.5.2](http://publicecodes.cyberregs.com/icod/ifgc/2012/icod_ifgc_2012_4_sec011.htm) or [409.5.3.](http://publicecodes.cyberregs.com/icod/ifgc/2012/icod_ifgc_2012_4_sec011.htm) > 6. Rigid steel pipe connectors shall be permitted to extend through openings in\*appliance \*housings. > 7. \*Fireplace \*inserts that are factory equipped with grommets, sleeves or other means of protection in accordance with the listing of the _appliance._ > 8. Semirigid tubing and \*listed \*connectors shall be permitted to extend through an opening in an \*appliance \*housing, cabinet or casing where the tubing or connector is protected against damage. Some local AHJ’s take a more conservative approach, but the IFGC allows it if protected. Check with your local codes to be sure. ---
**Author:** ![jpope](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jpope/32/59425_2.png) [@jpope](https://forum.nachi.org/u/jpope)\ **Post date:** [April 9, 2014, 1:14pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/3 "2014-04-09T13:14:03Z")
In CA, all furnaces and water heaters are connected with flexible appliance connectors. Perfectly acceptable as long as they are installed per building codes and manufacturers installation instructions. ---
**Author:** ![belliott](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/belliott/32/57038_2.png) [@belliott](https://forum.nachi.org/u/belliott)\ **Post date:** [April 9, 2014, 1:30pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/4 "2014-04-09T13:30:07Z")
John make sure the flex is one section with no connectors and that the flex does not go through the knockout. No picture so assume you are not talking csst. ---
**Author:** ![jreim](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jreim/32/60282_2.png) [@jreim](https://forum.nachi.org/u/jreim)\ **Post date:** [April 9, 2014, 3:07pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/5 "2014-04-09T15:07:11Z")
No it is not CSST. Here’s a pic. One thing I did not check (thanks Bob!) was if it entered the knockout of the furnace… ![P4080086.jpg](https://global.discourse-cdn.com/internachi/original/2X/e/e3a9c29654bb273aad3c4b4d255c32227d124985.jpeg) ---
**Author:** ![belliott](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/belliott/32/57038_2.png) [@belliott](https://forum.nachi.org/u/belliott)\ **Post date:** [April 9, 2014, 3:12pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/6 "2014-04-09T15:12:07Z")
John call it out for location and entry that may cause mechanical damage (under the Unit ) ? what the heck ?..that’s ridiculous. Also if more picture shots check for dirt leg,plus whats up with the condensate line ?..sorry off topic. ---
**Author:** ![jreim](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jreim/32/60282_2.png) [@jreim](https://forum.nachi.org/u/jreim)\ **Post date:** [April 9, 2014, 3:36pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/7 "2014-04-09T15:36:17Z")
Condensate drains out the other side. This is a water sensor for the drip pan. Thanks Bob ---
**Author:** ![jreim](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jreim/32/60282_2.png) [@jreim](https://forum.nachi.org/u/jreim)\ **Post date:** [April 9, 2014, 6:57pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/8 "2014-04-09T18:57:21Z")
Bob, you mean a picture like this? Just found this one, flex line entering knock out of furnace… underneath the furnace. Horizontal install in an attic. Go figure. The second pic is the hooks supporting the furnace screwed into the rafters, they are all bent and pulling out. An all around great install, not! ![P4080093.jpg](https://global.discourse-cdn.com/internachi/original/2X/b/bf5b5d9c8b95a3f768d014954905e85d9cc0436b.jpeg) ![P4080087.jpg](https://global.discourse-cdn.com/internachi/original/2X/4/41f2bfd37dc54ba2b2c80408339afe8e73032a41.jpeg) ---
**Author:** ![belliott](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/belliott/32/57038_2.png) [@belliott](https://forum.nachi.org/u/belliott)\ **Post date:** [April 9, 2014, 7:20pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/9 "2014-04-09T19:20:32Z")
Yep the vibration can cut the flex. Also like the vent at the powerfan.Hope its not the rangehood…instant fire.Even ignoring the mold created from a bath fan the plastic may get caught up in the thing… ---
**Author:** ![mclark2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mclark2/32/170907_2.png) [@mclark2](https://forum.nachi.org/u/mclark2)\ **Post date:** [April 9, 2014, 10:53pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/10 "2014-04-09T22:53:47Z")
I agree with the others. Even where flex line is acceptable, that installation is not. Call it out. ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [April 9, 2014, 11:30pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/11 "2014-04-09T23:30:46Z")
> [@jreim](#): > > Bob, you mean a picture like this? Just found this one, flex line entering knock out of furnace… underneath the furnace. Horizontal install in an attic. Go figure. The second pic is the hooks supporting the furnace screwed into the rafters, they are all bent and pulling out. An all around great install, not! > > ![P4080093.jpg](https://global.discourse-cdn.com/internachi/original/2X/b/bf5b5d9c8b95a3f768d014954905e85d9cc0436b.jpeg) > > ![P4080087.jpg](https://global.discourse-cdn.com/internachi/original/2X/4/41f2bfd37dc54ba2b2c80408339afe8e73032a41.jpeg) Great pictures, John, especially why flex shouldn’t pass through the knock out, as Bob indicated. 🙂 ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [April 10, 2014, 3:37am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/12 "2014-04-10T03:37:11Z")
I regularly find the protective grommets either inside the front cover or my favorite, installed on the other side of the cabinet in the un-used knockouts! :roll: * * * John, I meant to get this to you before for your records or reference material. Grayslake currently uses the 2009 IRC which is identical to the IFGC. > [@](#): > > 2009 IRC > **G2422.1.2.3 (411.1.3.3) Prohibited locations and penetrations.** Connectors shall not be concealed within, or extended through, walls, floors, partitions, ceilings or _appliance_ housings. > > **Exceptions:** > > 1. Connectors constructed of materials allowed for _piping systems_ in accordance with Section G2414 shall be permitted to pass through walls, floors, partitions and ceilings where installed in accordance with Section G2420.5.2 or G2420.5.3. > 2. Rigid steel _pipe_ connectors shall be permitted to extend through openings in _appliance_ housings. > 3. _Fireplace_ inserts that are factory equipped with grommets, sleeves or other means of protection in accordance with the listing of the _appliance_. > 4. Semirigid _tubing_ and listed connectors shall be permitted to extend through an opening in an _appliance_ housing, cabinet or casing where the tubing or connector is protected against damage. ---
**Author:** ![belliott](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/belliott/32/57038_2.png) [@belliott](https://forum.nachi.org/u/belliott)\ **Post date:** [April 10, 2014, 4:19am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/13 "2014-04-10T04:19:08Z")
Does not apply here Cam other than about protection which I have never seen at the knockout. Maybe just me but Damn codes are boring to read and take 1,000 words to say what we all said in one sentence. That’s why I like the forum so you guys can interpret for me into simple language. ---
**Author:** ![canderson5](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/canderson5/32/1814_2.png) [@canderson5](https://forum.nachi.org/u/canderson5)\ **Post date:** [April 10, 2014, 1:37pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/14 "2014-04-10T13:37:07Z")
> [@belliott](#): > > Does not apply here Cam other than about protection which I have never seen at the knockout. > Maybe just me but Damn codes are boring to read and take 1,000 words to say what we all said in one sentence. > That’s why I like the forum so you guys can interpret for me into simple language. In not sure what you are referring to when you say it doesn’t apply. It applies directly to John’s op. > [@jreim](#): > > Looking for an opinion on the use of a flexible gas appliance connector used to supply a furnace. **My memory tells me this is not allowed but wanted to check**. From the shut off valve to the furnace has to be hard pipe? Lack of sleep not helping my brain… Our opinions don’t determine if something is allowed. With protection at the knockout, it is allowed. ---
**Author:** ![rhorn](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rhorn/32/369330_2.png) [@rhorn](https://forum.nachi.org/u/rhorn)\ **Post date:** [March 22, 2018, 11:47pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/15 "2018-03-22T23:47:56Z")
Question for the group - "Can anyone please provide a code that either allows or does not allow CSST to be used on a roof? thanks Ray ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [March 23, 2018, 1:08am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/16 "2018-03-23T01:08:35Z")
> [@rhorn](#): > > Question for the group - "Can anyone please provide a code that either allows or does not allow CSST to be used on a roof? > > thanks > > Ray How do you mean “used on a roof”? Do you have pictures? We don’t know your location and it may make a difference. Many energy companies state that it needs to be protected from mechanical damage and corrosive environments e.g. [Flexible gas piping OK for exterior?](https://www.nachi.org/forum/f22/flexible-gas-piping-ok-exterior-19455/) post # 21 from 11 years ago. This is from Duke energy: 5.14 Outdoors When installed outdoors, CSST shall be protected from mechanical damage. A conduit or chase is required for installations in exposed unprotected areas within 6 feet of grade. Conduit shall be supported with proper size pipe hooks, pipe straps, bands, or hangers. Protective coating must remain intact outdoors. Mechanical joints and associated exposed metal tubing shall be wrapped or protected by shrink sleeves. Appropriate measures must be taken to shield CSST from corrosive environments such as exposure to acid or chloride based cleaning solutions for brick or masonry. Where passing through an outside wall, CSST shall be protected. CSST must be sleeved where passing though. Ray Horn, Next time you will get more and more accurate responses if you start your own thread and, fill out your profile. It is up to "Control Panel”, in the blue stripe, at the top of this page. Click on it. ---
**Author:** ![cevans](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cevans/32/244194_2.png) [@cevans](https://forum.nachi.org/u/cevans)\ **Post date:** [March 23, 2018, 1:16am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/17 "2018-03-23T01:16:13Z")
> [@rhorn](#): > > Question for the group - "Can anyone please provide a code that either allows or does not allow CSST to be used on a roof? > > thanks > > Ray Your answer will be found in the manufacturer’s design and installation guide, not too far from where they list the supports for roof mounting csst. Please don’t resurrect old threads to ask a new question. Leave the zombies in the ground. Start a new thread. ---
**Author:** ![lkage](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/lkage/32/347658_2.png) [@lkage](https://forum.nachi.org/u/lkage)\ **Post date:** [March 23, 2018, 1:17am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/18 "2018-03-23T01:17:16Z")
Here are some installation instructions: [CSST Installation Instructions - Flexible Gas Piping, How To Install](http://www.tracpipe.com/Technical/CSST_Installation_Instructions/) > **[gastite\_di\_guide.pdf](https://www.gastite.com/downloads/pdfs/gastite_di_guide.pdf)** > > 2.80 MB ---
**Author:** ![eschmidt](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/eschmidt/32/89375_2.png) [@eschmidt](https://forum.nachi.org/u/eschmidt)\ **Post date:** [March 26, 2018, 6:15pm UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/19 "2018-03-26T18:15:39Z")
Here you go, see page 42, keep in mind codes are always local. [http://tracpipe.ca/wp-content/uploads/FGP\_001\_DI\_Guide.pdf](http://tracpipe.ca/wp-content/uploads/FGP_001_DI_Guide.pdf) [http://tracpipe.ca/wp-content/uploads/FGP\_001\_DI\_Guide.pdf](http://tracpipe.ca/wp-content/uploads/FGP_001_DI_Guide.pdf) ---
**Author:** ![mdirocco](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mdirocco/32/285479_2.png) [@mdirocco](https://forum.nachi.org/u/mdirocco)\ **Post date:** [April 17, 2023, 11:16am UTC](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963/20 "2023-04-17T11:16:44Z")
Every intallation manual I’ve ever seen shows hard pipe comimg out of furnace. Usually “code” says to follow manufacturers instructions. Look at #6 in Camerin Andersons post. [Next page](https://forum.nachi.org/t/flexible-gas-appliance-connector/85963.md?page=2)