Drip legs

Hi fellow inspectors

I was inspecting an HVAC forced air furnace the other day and I saw this drip leg which does not cause the gas line to change a 90 degree direction, which I mark this as defective. The seller hire a HVAC guy and certified it as correctly installed, which make me look like I dont know what I am doing. Does anyone other than me seeing this as defective? Thanks


I see it.

The “HVAC guy” is wrong.

Improper Sediment Trap

The gas MUST make a 90 degree turn into the appliance so that gravity can catch any condensate or debris and drop into the Sediment trap. Theres no turn at this trap where gravity would properly cause debris or condensate to collect in the trap. It’s improper

How often are these cleaned out ?

I write these up at least once a week. Here’s a double from this week. I usually add a photo of the gas water heater’s drip leg as they are usually routed correctly (maybe the plumbers are more “educated” that the HVAC guys :D). (Note the gas flex lines going thru the cabinets as well :roll:)

drip leg.jpg

On another note, what if the furnace is in the second floor and a flex hose shoots up through the joist space right into the furnace. No visible trap, but any sediment in line would be left behind when hose runs vertically to the furnace?

Nick, sounds like it is time for another home inspection article.

Thanks for the post and you are correct.
Having worked in the field I can tell you that most HVAC guys have such a big ego they never admit being wrong and will argue they are always right and you are wrong.

Shucks I always thought that was the electricians:p:shock:

The code does not state how to configure the trap. Here’s what I say about it.

“The sediment trap was installed in the gas piping system at the IDENTIFY(appliance) in such a way so as to be mostly ineffective in trapping sediment in the gas piping system. In this case, the sediment is likely to blow past the trap. The trap serves to capture sediment before it enters the appliance and its absence may clog a valve or cause an equipment malfunction. Traps at all gas appliances are required by today’s commonly accepted construction standards; service by a licensed plumbing or mechanical contractor is recommended, but immediate service is not critical.”

I call these out on about 80% of my inspections.

That’s a great narrative, Joe, I think I’ll steal it if you don’t mind. :slight_smile:

In 11,000+ inspections since October 2001, I have seen a grand total of, wait for it, three sediment traps, two installed improperly. I don’t call out the lack of them because SDG&E doesn’t require them.

I was on site at the same time a local gas company contractor was there. I had already noticed the drip leg was not routed properly. Without any discussion, I notied he corrected it. When asked, he said they are instructed to correct them whenever they are found to be routed wrong.

It is installed incorrectly but probably will never be an issue. Gas pressure is so low that, if there is sediment, it shouldn’t blow past the leg.