Consequences of undersized gas piping.

mark ransley

The burners modulate, Mine does, so how can you have higher co and less life, flue gas condensation and delay ignition. How do you know pipe is undersized, do you test flow on these you know are undersized.

Wayne Heid_2

Consequences of undersized gas piping.

With the proliferation of tankless water heaters I have been seeing more and more cases of undersized gas piping (and meters). When explaining the consequences of this problem to homeowners I've been citing reduced equipment life, increased CO and flue gas condensation, delayed ignition, and reduced performance as potential problems. The most common response is "hmmmm, everything seems to be working OK". It seems that unless there's an immediate consequence most are reluctant to address the issue. Have others been getting a similar response? How are you handling these situations?

Timco

Red tag the equipment, and call the gas company. THAT gets their attention. Only had to threaten that once...you just cannot leave an under-fired piece of equipment running.

Tim

Leo G_103

with the newer

modulating tankless, if the gas line is undersized, it does not produce the quantity it was built for. try that. Some of these puppies can do over 9 GPM now. so turn on a tub, washer, etc. and explain to the customer how much hot water they are missing. If that don't work, don't sweat it.

Leo G

Wayne Heid

That's the frustrating part.

I called the gas company and they couldn't have cared less. Their position was that they are responsible to the meter and don't get involved with the indoor piping unless there's a leak. They will assist with pipe and meter sizing if asked upfront but they do not inspect installations. Many of the smaller towns in this area also do not inspect or require permits for this type of work. Pretty scary stuff.

steve_29

I got a simple solution... fix it for them.

If you don't know how, find someone who can.

Apparently whoever piped it, had no experience in determining required pipe size.

It's an easy fix!!!

Gordy

Yeah the burner modulates. So what do you think happens when You need full fire.

As long as the gas meter is the proper size for the additive amount of gas appliances that could be running at the same time. There should never be a problem, if proper gas piping practices are followed from the meter to the appliances.


Everyone forgets about the Gas Meter though. If its rated for 225,000 btus and you have 300,000 btus of appliances hooked up that could be firing at the same time one or all of them will suffer.

I don't know much but I know that.

Gordy

sootmonkey

"The most common response is "hmmmm, everything seems to be working OK". It seems that unless there's an immediate consequence most are reluctant to address the issue."

Yep, And you can tell by the look on their face that they are thinking, "Aw, this crook is just trying to get more money out of me."

I explain it to them, write it up on my invoice and have them sign it. I tried. I sleep.

Now you know how your doctor feels when he tells you to cut down on the.........

Mark Eatherton

If it ain't broke.... DON'T fix it....

That is the mantra of most homeowners. As long as they get a hot shower in the morning, they don't worry about it. Short them hot water, and BOOM the whole world turns upside down.

In reality, MOST fuel lines are marginally sized. There is load diversity, which means that it is rare that ALL appliances are running. When they are all running at the same time, there is a shortage of fuel to the appliances, but they stay lit and still make heat, so no one gets too upset about it.

Now, if you "show" the consumer what is going on in his combustion chamber, in the way of high CO, you MIGHT convince him that there is an issue. Key word is MIGHT. I have done that before, and the consumer thought I was being an alarmist because no one had gotten sick from CO poisoning in his house. I called the utility company and DEMANDED that they go shut off his gas. They had a supervisor call me, and I explained the situation to him, and they sent a rep of their own to check it out, and they did shut of his gas.

Tough love for sure, but if you touched it last, you are on the hook of liability.

ME

Wayne Heid_2

Here's the latest one I looked at.

This house has two tankless heaters (200K Btu each on high fire), a 100K Btu furnace, and a 60K Btu furnace all served by a meter capable of 225 CFH and the entire system was piped with a 3/4" gas line. The last appliance on the line was approx 120' from the meter and it was one of the tankless heaters. HO says everything seems to be working OK. He doesn't notice a problem. I offered to show him the manifold pressure readings and his eyes glazed over. Of course he doesn't want to hear the bad news. He just paid a handyman his hard-earned money to replace his tank-type water heaters with the tankless units. Now I show up to quote on a furnace replacement and tell him he needs new gas lines too? "The other contractors who quoted on this job didn't say I needed new gas lines."

steve_29

I can only assume there are no inspections done there.

Do you have to be licensed to perform this type of work?

There's no need for this to even happen.

Wayne Heid_2

sw .... Bingo! No license required, no mechanical permit or inspection required.

Wayne Heid_2

That's a great analogy. Come to think of it, I may have been guilty of that on occasion ....

Steve M_2

easy fix?

It's not always an "easy fix" to re pipe gas. With a finished basement or a tough crawl space, it isn't always accessible without major drywall repair. You can change it over to a 2 lb. delivery system and install a regulator at each appliance to get the correct pressure.

steve_29

" You can change it over to a 2 lb. delivery system and install a regulator at each appliance to get the correct pressure."

I'd consider that an easy fix. :-)

Supply House Rick

meter size

I have called the local gas companies many times to change to a bigger meter when adding additional appliances. Only on one occasion did the gas company install a bigger meter. Mostly I get the gas company stating that the meters can handle 1.5 times more than what they are rated for.

Jwp

World Plumber

The other contractors didn't say anything

It's amazing how many so called techs and contractors don't know the first thing about their jobs. They are only in it for the paycheck. Couldn't careless about doing their homework. "There is one there now it works, the one I'm putting in should work."
The Gas lines in my house are a bit oversized for the load. But I tried to take into consideration any conceivable furture load. I have a 2" line running most of the basement. With a load of a 200K Btu boiler and a stove that could concievely use 150K btu.
The charts are easy to come by. Yet most of the tech I talk to never heard of them. I was at an open house and asked one of the flex tube reps for a line size calculator. At least 15 people in the room asked what's that. (Scratch head) Can they possibly have any idea of how to size a gas line.
Then we have those who will put anything in that they can find laying around to cut their cost. Once they get their money they don't care if it works right.
The home owner just can't understand why her turkey wasn't fully cooded when it should have been.
Some guys like one I USED to work for know. He would charge for the right size pipe but wouldn't but it. (Get the drift why I don't work there) Well he would say to the techs how often is the furnace, the stove, and the water heater going to be running at the same time.
It's a like a breath of fresh air to read most of the posts on here. Because I can tell by the answer given most of the guys trying to help people out actually do know what they are doing.

Gordy

AND Wayne

If the homeowner has any intelligence YOU should be the one to get the job. One for having the intelligence to check for the gas sizing, and two for saving his equipment, and arce from harms way........ actually that should be number one.


Gordy

Mad Dog_2

I guess that is why we install only about 1 out of 10 inquires

for Tankless water heaters. From my experience I have found that roughly 25-30% of home and builing owners that we have encountered CARE enough or have enough respect to REALLY do things the right way. Typical responses: "you're the first one that told us that....so and so was hear...THEY'VE been in business since 1900!!!!!!....but the guy works for the gas company...the old company...the union....But my husband is a fireman....he said it waS FINE.....oh yes,we have CO detectors though!!!!!!" You know what it is....these people are willingly hoodwinked becuase they WANT "THE BEST" price. They take a leap...even though they often know better: "we'll I did have a feeling......no he didn't even have a business card

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steve_29

Good for you MD, unfortunately in this economy cut throat business practice will flourish.

There will be many that are only looking for a days pay and they will do what it takes to get it.

The deciding factor will be, just how much of a bargain the home owner wants.:-)

Most just love getting porked, but they did get such a good price.:-)

Mad Dog_2

I LOVE the look on their faces..................................

When I refuse to back down from the price of doing it correctly: "...WOW!!! you're willing to walk away from this...even in this economy?????" That actually will persuade a certain percentage of them: "....you're right...I wanna do this the right way." Mad Dog

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Mad Dog_2

Another common thing we here w/ tankless hwhs

"why can't wejust vent it in to the chimney...the other company was going to do that....but its just an air chase...it goes to the outside air (yeah an air chase with windows on all sides...just waiting to suck some CO in to the space. Mad Dog

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Mark Custis

I too am

not doing the resession.

We do business just like Matt.

We do it correctly or not at all.

TY Mad Dog.

Mark and Steph

BRIANJ

Thanks for the information

Hey Wayne, Thanks for starting this thread.

After reading through these postings I called PSE&G, NJ and asked them if I had enough gas and pressure coming through the line to properly support our boiler 287K BTU's, on-demand hot water 199K BTU's, gas dryer and upcoming gas stove.

He examined the gas piping 1.5 inch main and .75 inch feed to each appliance and said it was sufficient but he is ordering a larger meter that will handle the load better. He said the supply pressure was fine.

Thanks again everyone for sharing the information.

Brian