Thread: Sediment trap for a tankless water heater

Hello!

Looking at this installation of a tankless water heater, the gas line has a regulator but not a sediment trap. One is required, correct?


Thanks for the help!

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G2419.4 (408.4) Sediment trap.
Where a sediment trap is not incorporated as part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical.

The sediment trap shall be either a tee fitting having a capped nipple of any length installed vertically in the bottommost opening of the tee or other device approved as an effective sediment trap.

Illuminating appliances, ranges, clothes dryers, decorative vented appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills need not be so equipped.

Originally Posted by ROBERT YOUNG

G2419.4 (408.4) Sediment trap.
Where a sediment trap is not incorporated as part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical.

The sediment trap shall be either a tee fitting having a capped nipple of any length installed vertically in the bottommost opening of the tee or other device approved as an effective sediment trap.

Illuminating appliances, ranges, clothes dryers, decorative vented appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills need not be so equipped.

So the trap would be installed right below the regulator, correct?

- - - Updated - - -

It's not required everywhere.

Originally Posted by JIM MURPHY

So the trap would be installed right below the regulator, correct?

Questions:

I would expect the manufacturer to recommend, or exclude, if a sediment leg is required.
Also,
Something feels amiss with the image you have provided.
Typically, normally I see the pressure regulator downstream and close to the meter.
I see a NG supply protruding from the wall.
1: Where is the NG meter?
2: Where does the CSST lead.
The CSST NG/LP pipes require bonding/grounding.
Exterior CSST have sparked, excuse the pun, debate and class action suites.

Originally Posted by JIM MURPHY

So the trap would be installed right below the regulator, correct?

Sorry for not answering your question.
IRC states; Illuminating appliances, ranges, clothes dryers, decorative vented appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills need not be so equipped.

It appears you are without a sediment leg to stand on and have not fallen through a sediment trap.
Ops. There I go again. Please excuse the pun.
I concur with your hypothesis BUT will also admit I have never seen a regulator and NG pipe on an angle.
I await others to chime in.

Based on the presumption of what is not shown in that photo (that the gas pipe goes directly above to the water heater located directly above) - a sediment trap is required downstream of that shut off valve, either before or after the regulator, or up at the appliance presumed to be at the top of the photo.

Jerry, 2 questions.
1: Is there a prescribed method of installations for NG regulator valves and clearances?
2: Based on the image if a sediment trap was installed after the regulator valve wouldn't the regulators mechanism act as a segment trap thus possibly inhibiting functionality?

NG/LP regulator valve Clearances.
Been some time but I thought in case the regulator valve operated, say due to line overpressure, I though the expelled NG/LP should be vented in a specific direction.
Away from wall intake vents, B vents, windows or air intake vent openings to eliminate the possibility of air contamination or even an explosion.
Thanks as always.

According to both the Nat'l and Int'l Fuel Gas Codes you must have an approved shutoff immediately upstream of a Medium Pressure regulator AND a sediment trap. You must also have another trap or other means of attaching a manometer immediately on the downstream side. There must be a ground union or other suitable means of disconnecting the piping for service or replacement.

Other problems from this pic:
- lack of support on either side of the reg.
-undersized. If this is your typical ~165 MBH tankless WH, I doubt that gas line is sized properly. Other gas appliances may suffer from undergassing if this is undersized, which can lead to sooting, carbon monoxide formation and prolonged heating times/ reduced capacity.
-The vent protector is downsized. While you don't need a vent limiter when located outdoors, you do need the blue protector but it cannot be downsized as was done with a bushing here. This would reduce the venting capacity, which is a code violation.
- The AHJ would have to rule on the proximity of that switch but in my book its an ignition source within 3 feet. You could simply run a full sized pipe of approved material from the vent to an ignition-free zone but you'd still have to protect the termination from rain and bugs.
-I'd look up that reg. to ensure its approved for outdoor use. A typical Maxitrol 325 series is but this appears to be something else. what make and model?
-lack of electrical bonding on the CSST.
-depending upon the pressure system in use, it could require an Over-Pressure Device or OPD.

Please provide details including more pics and BTU rating of WH.

I don't care what your local yocals tell you about lack of codes in your jurisdiction. If there is an incident resulting in damages involving insurance or litigation such as personal injury, I can assure you one of the two model gas codes WILL be applied by the Trier of Fact to determine responsibility. EVERYTHING in the US should be built to the applicable code where there is an identifiable code pertaining to that situation.

Much thanks.
Greatly appreciated.

Originally Posted by ROBERT YOUNG

Questions:

I would expect the manufacturer to recommend, or exclude, if a sediment leg is required.
Also,
Something feels amiss with the image you have provided.
Typically, normally I see the pressure regulator downstream and close to the meter.
I see a NG supply protruding from the wall.
1: Where is the NG meter?
2: Where does the CSST lead.
The CSST NG/LP pipes require bonding/grounding.
Exterior CSST have sparked, excuse the pun, debate and class action suites.

The gas meter is to the left of this and is bonded. The CSST leads to the water heater.

Originally Posted by JIM MURPHY

The gas meter is to the left of this and is bonded. The CSST leads to the water heater.

Thanks Jim.

Bob Harper's post is direct and to the point.
Thanks again Bob!

I do not inspect NG often but spent many hours on the subject during my first commercial/residential inspection. 3 years ago.

I point out installation safety and other marking defects and have always seen a sediment trap at the tee and capped just downstream of the meter.
Actually the last inspection with NG tested positive for a leak at the pipe union to the meter. I recommended calling gas metropolitain. It's there service side if I am not mistaken.

Hope everything helped!
I thought it was a rewarding thread.

Originally Posted by ROBERT YOUNG

Thanks Jim.

Bob Harper's post is direct and to the point.
Thanks again Bob!

I do not inspect NG often but spent many hours on the subject during my first commercial/residential inspection. 3 years ago.

I point out installation safety and other marking defects and have always seen a sediment trap at the tee and capped just downstream of the meter.
Actually the last inspection with NG tested positive for a leak at the pipe union to the meter. I recommended calling gas metropolitain. It's there service side if I am not mistaken.

Hope everything helped!
I thought it was a rewarding thread.

It was a rewarding thread and thank you for your input!