Question about Appliance connectors in furnaces

[walker]

I came across a furnace with an appliance connector used to supply gas after the shut off.  I was pretty sure you cant use them in furnaces but I couldn't find the code which states that, also there was union installed after the shut off.  I've come across this before after enbridge had been out to red tag it, but I cant remember what code they used. would it be code 6.21.3, because it does not state you can use one to connect to a furnace, other than a wall furnace?? and whats the code pertaining to having a union installed?

1. can you use appliance connectors in a furnace?
2. does there have to be a union installed?


thanks.

[Admin]

Maybe Clause 6.21.3(c) prevents us from using a metal gas connector on a furnace installed as a free-standing unit.

Clause 6.21.3 - Except as specified in Clause 7.22.3, a corrugated metal gas connector certified to ANSI Z21.24/CSA 6.10 may be used to connect
(a) a range, refrigerator, clothes dryer, or built-in counter appliance to piping or tubing, provided that the connector length does not exceed 6 ft (2 m);
(b) a suspended appliance to piping or tubing, provided that the gas connector length does not exceed 2 ft (600 mm); or
(c) a decorative appliance, a room heater, or a direct-vent wall furnace to piping or tubing, except when the appliance, heater, or furnace is installed as a free-standing unit, provided that the gas connector length does not exceed 2 ft (600 mm).

See Clause 6.21.7,

Clause 6.21.7 - A gas connector not exceeding 2 ft (600 mm) may be used on a vented appliance, such as a free-standing space heater, provided that the appliance is secured to prevent dislodgement of the vent.

The furnace in your picture would be secured in place by the ductwork.  We might be misinterpreting Clause 6.21.3(c).  A standard upflow furnace may not be considered a free-standing unit.

We could satisfy Clause 6.21.3(b) by installing the furnace horizontally and suspending it.  If a gas connector is allowed with this furnace installation it makes sense that a gas connector could be used on the same furnace installed in the upflow position.

To answer your original questions I think you can use a gas connector as long as it complies with ANSI Z21.24/CSA 6.10 or ANSI Z21.69/CSA 6.16 or ANSI Z21.75/CSA 6.27.  Clause 6.21.6 seems to say we can use a gas connector and I don't see the need for a union if there's a flare fitting or gas connector fitting that could be disconnected.

The only Clause I can find about a union is,

Clause 6.14.4 - A union or a combination of fittings designed and intended to act as a swing joint shall not be used where piping is concealed.

Check the installation manual to see if it calls for a ground joint type union, in which case we follow Clause 4.1.3,

Clause 4.1.3 - An appliance, accessory, component, equipment, or any other item shall be installed in accordance with the manufacturer's certified instructions and this Code.

If your union is upstream of the shut off I would use Clause 4.4.1 on the warning tag,

Clause 4.4.1 - All work shall be done in a skillful, thorough manner. Careful attention shall be paid not only to the mechanical execution of the work but also to the arrangement of the installation.

Is there a dirt pocket on that gas line?  It should be installed on the bottom of the final drop serving the appliance.  The elbow upstream of the gas connector should be a dirt pocket.

Clause 6.13.1 - A dirt pocket shall be installed at the bottom of any piping or tubing on the final drop serving an appliance other than
(a) an illuminating appliance;
(b) a range;
(c) a clothes dryer;
(d) an outdoor grill;
(e) a portable appliance or equipment;
(f) a decorative appliance;
(g) a gas log;
(h) a room heater; and
(i) an appliance incorporating a sediment trap.

Also is that a 60,000 or 80,000 BTU furnace?  Does that CVENT change to BVENT?  That's a Category I appliance and depending on the chimney height, number of appliances and the furnace's BTU rating, you may require a double-wall vent connector, as per Table 8.5.  Use Tables C.2 or C.4 to verify your furnace is above the MIN and below the MAX rating.

To answer your questions,

1. can you use appliance connectors in a furnace?

2. does there have to be a union installed?

1. No, not inside a furnace.  It should never enter the furnace cabinet as shown in your pic.  Hard pipe the furnace gas valve into a dirt pocket, then you can use a gas connector between the dirt pocket and shut-off valve.  A gas connector also has to be protected from physical damage as per Clause 6.21.2.

2. No, not unless the appliance manual says so.  (most furnace manuals call for a ground joint union but some water heater manuals do not).  There are no Gas Codes that say a union must be used.

[walker]

It was a 60MBTU furnace and yes it did turn into a B-Vent. There is a dirt pocket closer to the shut off. I've had enbridge red tag other furnaces citing no union was installed when using CSST up to the shutoff, so what you're saying it that should not apply. What constitutes a ground joint union? Also I believe 6.21.3(c) refers to a direct vent wall furnace. What exactly does free standing mean? Does that just mean it's not suspended?

[scarey8]

Inspectors in my area (Kingston) do not allow CSST installs without the installation of a union downstream of the CSST drop.  In the install instructions for Gastite particularly, they state that the compression CSST connection must be re maid if disconnection is required.  IE cutting the CSST back to allow the compression flare to made again.  Long and the short, with using gestate, CSST connection does not act as a union.   

[Porcupinepuffer]

As of lately, our company has been getting some grief from the odd inspector for not using unions on our jobs with copper at the furnace. I'm assuming it's because they don't want the flared copper/csst  to be used as a disassembly point for servicing as I'm under the impression they consider those to be one time connections and new flares are to be made if taken apart? ...I've personally undone dozens of flared connections and have never seen one leak upon re-tightening.
I can see this rule making sense to CSST, If you suddenly had a problem, the chances of having another $30+ same brand of brass fitting is unlikely, and then you also the CSST with the internal gaskets that can make re-using a connection a problem.
I wish a rule like this was written in writing from Enbridge so there would be less confusion and less failed inspections.
So no flexible connector is allowed, and unions are still required.

[Admin]

Inspectors in my area (Kingston) do not allow CSST installs without the installation of a union downstream of the CSST drop.  In the install instructions for Gastite particularly, they state that the compression CSST connection must be re maid if disconnection is required.  IE cutting the CSST back to allow the compression flare to made again.  Long and the short, with using gestate, CSST connection does not act as a union.

I don't see anything in the Gastite manual about having to redo the connections if they are disconnected.  Section 5.3.2 says,

The Gastite®/FlashShield™ mechanical joint fittings can be removed and easily re-attached.

The Tracpipe CSST manual says,

If the fitting is reattached more than three times, or if the nut cannot be pulled over the rings in any position, then the split-rings must be replaced.
Packets of spare split-rings are available (P/N FGP-RING-SIZE) and the remaining fitting parts can be re-used.

I guess it depends on the CSST manufacturer.

I looked at the Gas Code and I can't find a Clause that says unions are even required.  Does anyone know, where in the Gas Code, does it state a union is required?  I think installing a union with CSST is the safe bet.

Most appliance manuals will have their own requirements regarding unions.  The following is from the GSW 6G5076N water heater manual,

There must be:  A flexible gas connector or a ground joint union between the shut off valve and control valve to permit servicing of the unit.

The following is from the Lennox ML195 furnace manual and I posted a couple of pictures from the manual below.  Notice how the gas connector is installed outside of the furnace cabinet.

In some localities, codes may require installation of a manual main shut-off valve and union (furnished by in­staller) external to the unit. Union must be of the ground joint type.

Gas connector may be used for Canadian installation if acceptable by local authority having jurisdiction.

The following is from the Amana AMV9 furnace manual,

To connect the furnace to the building's gas piping, the installer must supply a ground joint union

The Amana AMV9 manual also says,

A semi-rigid connector to the gas piping can be used outside the cabinet per local codes.

With the Amana AMV9, if I used a gas connector I would still install a union because the manual says the installer must.

Our Gas Code states,

Clause 6.2.21 - Corrugated stainless steel tubing (CSST) shall not be used as a gas connector.

Clause 6.11.5 - Corrugated stainless steel tubing (CSST) systems and copper tubing shall only be connected to an appliance secured in place (nonmovable).

Gas connector — a factory-fabricated assembly consisting of gas conduit and related fittings designed to convey gaseous fuel from a gas supply piping to the gas inlet of an appliance. A gas connector is not intended for vibration isolation, nor expansion or contraction control. For the purposes of this Code, solid gas connector includes
(a) gas connectors for gas appliances that are not designed for repeated movement after being connected nor for repeated disconnecting and connecting and are not intended to be used with quick-disconnect devices or convenience outlets;
(b) gas connectors for movable gas appliances that are designed for repeated movement on a regular basis and could be used with quick-disconnect devices or convenience outlets; and
(c) gas connectors for outdoor gas appliances and manufactured homes that are designed for supplying gas to an appliance for outdoor installation that is not frequently moved after installation and to the gas inlet on a mobile home.

[walker]

So what I'm gathering here is you have to have rigid pipe into the furnace, and it's up to the manu. Instructions say if a union is required or not?

[Admin]

I think the only way you can connect rigid is if you install a union, unless you have a single gas appliance and pipe back from the appliance gas valve to the gas meter.  I can't seem to find any Code that requires a union though.

I know Enbridge in Ottawa will accept a copper flare fitting or CSST fitting and does not require a union in this case.

I attached a picture of the Gastite manual Section 4.62.  It says that Gastite may be connected directly to non-movable appliances such as furnaces.  It also says that Gastite should not penetrate the metallic cabinet of the appliance.  This seems like a contradiction to me, but ultimately the word "should" is not a mandatory requirement.  In the picture where it shows the union, it says (if required by code).

[walker]

Well to be on the safe side I will just always use rigid in to the furnace and use a union downstream of the csst

[Porcupinepuffer]

I know Enbridge in Ottawa will accept a copper flare fitting or CSST fitting and do not require a union in this case.

With residential furnace installs (where we splice in a length of copper between the shut off valve and dirt pocket), there have been a few Ottawa Enbridge inspectors rejecting those jobs because of no unions. They don't seem to want any servicing being done by a means of disconnecting the copper and/or CSST... This only came up within the past couple of months, so we've been tossing them on just to avoid the grief.

[harshal]

I think it depends on the inspecteor that what admin means rather than the general rule.

[Admin]

With residential furnace installs (where we splice in a length of copper between the shut off valve and dirt pocket), there have been a few Ottawa Enbridge inspectors rejecting those jobs because of no unions.

I'm curious what Clause they would use to enforce this, if the appliance manual does not require a union.

[Admin]

The Gastite guide section 4.6.4  does not allow Gastite to penetrate a fireplace cabinet, but does allow the use of FlashShield.

This seems to contradict section 4.6.2.

[Samjohn]

Hi .
It's my first post. Just joined.
Would these points being discussed still apply to commercial roof top units?

[Samjohn]

Just remembered
Codes 6.20.5 (c), 6.21.2 (b).
I was told by my local TSSA inspector that the above codes pertain to unit cabinet walls too.
Best practice use rigid pipe inside cabinet and attach connectors/metallic hose/CSST outside.

[Admin]

Clause 6.20.5 - A metallic gas hose
(a) may be used to connect an appliance in commercial, industrial, or process applications when vibration, expansion, contraction, or other circumstances of an appliance installation warrant its use;
(b) shall not be used in a concealed location;
(c) shall neither extend from one room to another nor pass through any wall, partition, ceiling,
or floor; and
(d) when used to connect an appliance to rigid supply piping, shall have a shut-off valve in the piping
immediately upstream of the metallic gas hose.

Clause 6.21.2 - A gas connector shall
(a) be protected from damage;
(b) not pass through a wall, floor, ceiling, or partition;
(c) be connected to rigid piping or tubing located in the same area as the appliance; and
(d) comply with Clauses 4.5.2 and 4.9.1.

I'm not sure if the furnace cabinet can be considered a partition, but it might be interpreted that way.

[NoDIY]

most appliance installation manuals ask for a ground joint union. So that pretty much makes you go black into the cabinet of most furnaces and water heaters

4.1.3 would be the warning tag pointing to the installation manuals requirement for a ground joint union.

Use of union is not in the B149.

[Mmtc79]

Wardflex rin right into furnace cabinet with union inside is allowed ?

[NoDIY]

What does the current manual say?

[Admin]

Wardflex rin right into furnace cabinet with union inside is allowed ?

Where is your dirt pocket?  Are you using the CSST from the dirt pocket to the union and gas valve?  If so Clause 6.2.21 says you can't use CSST as a gas connector.

The Wardflex manual says it can be directly connected to a furnace but recommends terminating the CSST at the appliance shut-off and shows rigid piping being used to the gas valve.  Also the furnace manual may say if a union is required.  Some manufacturers allow unions inside the furnace cabinet and some do not.  You almost always have to use rigid pipe out of the furnace cabinet into a dirt pocket to ensure the dirt pocket is at the lowest point to satisfy Clause 6.13.1.

4.6.2 NON-MOVEABLE APPLIANCE
A. WARDFLEX®/WARDFLEX® II can be directly connected to a non-moveable appliance such as a furnace or water heater (Figure 4.21) (be sure to check with local code if this is acceptable prior to installation).
B. In this type of application, no termination fitting is required and the CSST should be terminated at the appliance shut off valve.

Clause 6.13.1 - A dirt pocket shall be installed at the bottom of any piping or tubing on the final drop serving an appliance