Flexible copper 1/2" gas line to water heater -- how big an issue?

Yesterday evening I did an inspection in which there had been some “weekend warrior” renovation done on the house. One of the issues was a water heater gas line which was evidently 1/2" outer diameter flexible copper piping, which ran along the floor, up a bit behind the unit, down almost to the floor alongsicde the unit, and up to a short length of proper rigid gas line to the controls.

Obviously this is an improper installation, and I told my clients the line should be run with rigid gas line with a “drip leg,” and would get info as to how significant it really is.

How big an issue is this, really, and why? It’s not that all that difficult to correct, but the water heater appears to be working fine as it is, and I don’t want to make a mountain out of a mole hill or gloss over a potentially dangerous condition.

Have a picture?
Copper runs to gas appliances is common here but there may be other issues and a picture would help.

I do, but it’s still on my camera. Evening inspection.

Is this natural gas or LP ?

Call your local gas company and ask if copper is even allowed in your area.

I haven’t had time to research this, but I’m pretty sure that this is a safety hazard, and that there is a chemical compound in gas that “eats” copper.

You’re correct Keith. It’s the hydrogen sulfide (the chemical added to give an odor to natural gas).

Copper piping is allowed for gas piping in areas where the hydrogen sulfide levels are low enough (less than .3 grains per 100 cubic ft.), but this varies by the supplier. CPC 1210.1.1

Yes, found out that at least the newer copper is okay. Thought for a moment I had had a bad dream. Everyday I’m reminded how little I know.

Now this is getting really confusing. Newer copper or older copper? How much hygroden sulfide?

The copper line did not appear to be new. Definitely tarnished, but did not look very old. The gas company varies in my metro area.

Just to further muddy the waters, how much an issue is the lack of a “drip leg” (bearing in mind the line slopes somewhat upward to the elbow)?

That’s another “regional” issue. Here in CA, I rarely see a drip leg installed, as they are not required in the Los Angeles area.

Check with your local utility. They are best qualified to answer both of your questions.

Thanks, guys.

I have a very, very good nose for gas leaks, and none were detected.

question for ya

the yellow flexible gas lines are they ok?
did an inspection today and there was a yellow flexible, meaning looking crimped line installed on the gas line, I know that in new construction they are using yellow flex lines, but this one was crimped looking not smooth like I’ve seen in new construction, It was installed by the owner and his brother

It’s sounds as if you are referring to an appliance connector, which would be the proper method for supplying a water heater or other gas fired appliance.

Any pictures available?

Are you referring to the following?



I have seen this type of connection on gas lines on new construction that you are showing here and it was not that type, in fact we had a bit of disagreement about the type you are showing and what I saw.

I have never seen this kind I am trying to describe here before and sorry no pics, to me the line I saw yesterday looked and felt like plastic, it was yellow and it was crimped not smooth (like copper flex tubing that is crimped)
I wrote down the part number it had on it #CSSD54-48

I know that the HWH was installed by the owners son and he wasn’t sure where he got the line???
so just wanna be sure, since the listing agent was questioning me.
thanks for the help

Like Jeff said: it’s a gas appliance connector.

See link below:

You can purchase approved CSST flex gas line material in bulk. The key is that you must use a special swaging tool to properly install the end connectors to the gas line.

If a homeowner installed the end connector himself, I would have concerns about the long term reliability of that joint. He’s going to have to prove to me that he followed the manufacturer’s instructions for using this material properly.

BTW, we are seeing a lot of CSST being used in new construction and additions. Like PEX tubing, it saves the builders lots of labor time to install.

thanks for the link and that is it exactly, I did ask for a plumber to check the line to be sure it was installed correctly, but I know the listing agent was not happy at the time of inspection that I asked for it and figure that is one item I don’t think he is going to enforce his owners to “take care of” even though the owners son, not a “licensed plumber”, a handyman installed this unit.

how can WE be sure they used the correct swaging tool?

this is the first time that I have seen this line installed and when I questioned the one who installed the line, he did not seem to know a whole lot about that line itself.

thanks for your help

Your responsibility as a home inspector is to check the current condition of the house. When it comes to a gas line, the most you should do is to use a combustible gas detector and sniff for gas leaks. Anything above and beyond the SOP is putting additional liability on you.

If the gas line was recently installed, it should have been installed to the local building code requirements. One thing for sure you can put a bet on is that the building department does not like amateurs playing with gas lines. You could have noted that the gas line was recently replaced and that the buyer and his/her agent should make sure that the work was done with the proper building permits.

BTW, whatever the listing agents thinks about you is secondary. Your responsiblity is to your client. Yes, any agent can put the word out on the grapevine that you’re a “deal breaker”. Well, gas leaks or improper gas line connections are very important to the safety of your client. If the house blows up, you’re going to be the first one they blame and you can guarantee that the agents will plead that you never told anyone of the problem.


I understand and tell my clients I work for them even in front of the disgruntled listing agent, they don’t really bother me, but this guy was pushing and pushing me, of course with being a female, I get challenged ALOT. I just wanted to cover myself with what I wrote, which I did.
The house was a 1964 it wasn’t new construction and again I have not seen that type of connection used so better safe asking then being sorry. There is something to learn every day!