We've had some excellent questions sent to us in response to the CSST story.
I'd like to let Matthew Brady, the author of the magazine article, have a go at answering some of them.
Tom H. submitted a series of well-thought comments and questions that I think are indicative of what a lot of you may be thinking. Tom's comments/questions are emboldened, and Matthew's responses can be found in italics.
An otherwise good article but it totally lacks:
1) An explanation of how the fire is started
A direct or nearby ground strike can energize the lines and cause problems. I think this explanation got lost in the editing process.
Firefighters tell me lightning is unpredictable. It can strike 100 yards away and somehow bounce or otherwise work its way into a house. In a house with CSST, it can potentially charge the line and puncture it as it seeks the easiest path to ground. The fire is caused by the combination of gas and electrical spark from the lightning. This sequence of events may or may not happen. As the fire chief in the story told me, he's had many houses with CSST struck by lightning with no resulting fire.
2) An explanation and picture of a correct installation
Each manufacturer offers slightly different methods to bond and ground.
They all accomplish the same thing but by slightly different means. Therein lies the complexity of the issue: There's no one 'right' way to do it, but the system should be bonded and grounded.
3) I am not sure you are correct in saying the short flexible lines seen between BIP and the furnace are NOT CSST
This is what the experts tell me. The line between the appliance and the wall has been around long before CSST was invented and is called a 'flexible appliance connector' among other things. It, too, is corrugated and steel but is much thicker than CSST.
4) Isn’t CSST in yellow plastic sold in hardware and big box stores?
CSST is not sold in big box stores, per the manufacturers. By law, you have to hold a 'certificate of training' to buy it.
5) You might mention that the newer high efficiency furnaces that use plastic pipe flues shouldn’t have this problem.
See point 1.
I infer:
1) Lighting strikes the vent, runs through the furnace to ground through the gas hookup, passing through the CSST, rupturing it and starting a fire
It could happen that way, but the lightning can strike anywhere on or near a house and cause problems.
2) Is a solution: Connect the furnace to a cold water iron pipe with solid copper ground wire or bridge over the CSST with solid copper grounding wire from the fittings on each end (or further back from the fittings)? Alternatively use an insulation break in the flue. How about replacing the CSST with PEX (that has other issues)?
I can't even begin to address this! You know more than me. That sounds logical. One concern a fire chief brought up: Many newer cold water lines are plastic from the house to the street, so you lose the effective ground.
3) Why not include a comment about gas leaks from roofing (or other) nails that penetrate CSST running through hidden spaces in attics?
A good point. I heard this from a couple of people, but fire folks tell me they don't run into this very often.
*And, in response to the readers who were curious as to why we didn't provide any DIY tips:
The story did steer away from some of the more technical aspects because our audience is broad. Calling a licensed electrician or third-party inspector is the simplest, clearest, most accurate advice I can give to a reader who identifies CSST in their house but may not know the first thing about plumbing or electricity.
Link to the CSST settlement: http://www.pddocs.com/csst/
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