Hello everyone!

I'm trying to trouble shoot a problem I'm having with an outdoor natural gas bbq. We've only recently moved in, but understand that the BBQ was functioning some weeks before moving in.

So far, my diagnostic has yielded the following:

BBQ is natural gas. BBQ is located in an outdoor kitchen/bbq island. The island is about 15 feet from the nearest wall in the house.

Ostensibly, the island is supplied gas via an underground line running from the back of my garage, under the concrete patio, into the kitchen island.

There is a yellow petcock-like gas valve coming out of the back of the garage and into the concrete. This, presumably runs to the bbq island.

In the island, under the bbq in the cabinet, is a line coming out of the ground, going through a red handled valve petcock-like valve and then split into a T. Each end of the T goes into a regulator and then into a flexible metal line into each of a bbq and a stove burner.

With both the yellow and red valves open (running in line with the flow of the pipe), no gas is reaching the bbq. Can't hear or smell gas when cycling the knobs on either the bbq or stove.

With everything wide open, the gas meter at the main is not reading any movement.

I'm stumped. My current hypothesis is that the one or more valves are stuck in the closed position and turning the valves isn't actually doing anything. Second hypothesis is that the pipe under the patio somewhere rusted through and filled in with dirt, completely plugging the line.

I had a plumber out here working on something else, and he took a look. He took apart everything under the bbq, and used a gas sniffing device and nothing coming out of the line. Not wanting to trouble him any further, he just doped up the fittings and put everything back together before he left without any real indication on what might be wrong.

There is probably a valve at the tee coming off the gas trunk line. Basement, crawlspace?

Ball valves on gas lines nearly never malfunction to the point they appear on but are off. I've not seen that in 30 years but did once with a ball valve on a water line.

And to the silt/dirt-filled gas line, no, that would not happen. In theory a gas pipe could be filled with water, enough to block flow, but that is unlikely.

What other items in the home use the natural gas?? . Are the functioning properly ? if so then I would suspect the is another closed valve some where in the system................... drill sgt.

quote:

Originally posted by Woodman:
There is probably a valve at the tee coming off the gas trunk line. Basement, crawlspace?

Ball valves on gas lines nearly never malfunction to the point they appear on but are off. I've not seen that in 30 years but did once with a ball valve on a water line.

And to the silt/dirt-filled gas line, no, that would not happen. In theory a gas pipe could be filled with water, enough to block flow, but that is unlikely.

Truly stumped now.

Any possibility this won't cost me several thousand dollars?

quote:

Originally posted by drill sgt:
What other items in the home use the natural gas?? . Are the functioning properly ? if so then I would suspect the is another closed valve some where in the system................... drill sgt.

Stove, furnace, water heater all function normally on natural gas.

I have a fireplace that's capped for the time being.

Is there a shutoff at the grill? Newer grills have a safety feature that if the burner controls aren't in the off position when the gas line is opened the flow is blocked.

Were the burners in the off position when the gas line was opened?

Would a call to the gas co. help or maybe point you in the right direction.

quote:

Originally posted by Aeteocles:

quote:

Originally posted by drill sgt:
What other items in the home use the natural gas?? . Are the functioning properly ? if so then I would suspect the is another closed valve some where in the system................... drill sgt.

Stove, furnace, water heater all function normally on natural gas.

I have a fireplace that's capped for the time being.

I'll run a diagnostic again, to test this. But, the plumber wasn't able to detect even trace levels of gas with the T and regulators off.

No basement, no crawlspace. Previous owner has video demonstrating proper function, but no idea why it doesn't work now.

Does your grill have a thermocouple running near the gas valve area to the burners?
Looks like the small metal line in this photo and is a safety device in case the flame goes out or doesn't start it cuts the gas supply.

The chances of both regulators failing is slight.

Gas pressure is so well regulated these days, here, before it hits the meter, and over all, at the meter, that regulators on appliances are increasingly unnecessary - although your codes may say differently (I've gotten this from grill manufacturer reps).

No, it is something you can figure out. Post some pics or email if you want. I'd figure out where the gas enters the structure and follow the line from there.

Gas ball valves have the little lever or butterfly handle which is inline when on, perpendicular when off (woo-hoo! five-syllable word!)

If I was truly stumped I'd shut the gas off at the grille and spin off a regulator. Then open the valve. You would hear and smell gas. Sounds like you did this already: the plumber wasn't able to detect even trace levels of gas with the T and regulators off.

My thinking is that the original installer put a tee on the trunk line with a valve. They'd be able to run the rest of the line without shutting off the gas if there was a valve at the trunk.

Then they ran the gas to the garage, and code probably required the valve before it went underground.

So it is the first as-yet unlocated valve which is probably off.

Never assume or presume. It will be the last place you look.

Roger that. Time to go hunting.

1. There is another valve upstream
2. There is a valve at the tank or where it comes from the street and goes thru a regulator.

If the house was vacant for any time I’m sure the city turned off the gas at the street it at the house to avoid explosions.

My kids house is fed gas by the city, this is what they did. It won’t look like a valve, his was able to be padlocked closed, the city had only put a wire tie plastic thinly to show it was off. A pair of pliers and the gas was back on.
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And yes valves can go bad, as well as the diaphragm in the regulator...there is a tiny hole on one side of the regulator that is supposed to be there and open to atmosphere...wait till ice or a bug clogs that up! Then you are in for good times.

Did you try turning the gas shutoff the other way (reverse threads)?

My two guesses.

A shut off near gas manifold, or you don't have valves in correct orientation. The gas shut offs will align with piping for open and cross it for closed.

Those Regulators can fail. Though I've never had one on a Natural Gas appliance, I've had them fail on Propane systems. I'd disconnect the regulator and then check to see if you have gas at the shut off valve. If so, replace the regulator.

I have no experience with natural gas but have a home made smoker, wood/propane grill. I have had the propane valves clog up several times. Simple fix to disassemble and clean.

Updates and additional information.

Gas in the rest of the house has been functioning normally over the past 8 weeks. Gas dryer, furnace (two), stove, water heater.

I opened up the wall where I think the gas is coming from the house and heading to the BBQ island. The path looks like this:

Street -->
Meter -->
Into the House, presumably up to the laundry room and attic furnace, the house is on a post tensioned slab, nothing underneath -->
down inside an exterior wall from "up" into the house -->
split off to water heater -->
15 inches away, out the exterior wall -->
ball valve (yellow)-->
into the ground, presumably to BBQ island -->
out of the ground under the BBQ -->
ball valve -->
T split -->
each of two regulators -->
each of two flexible lines -->
into each of the BBQ and outdoor stove.

So, the takeaway from above is that the Water Heater is getting gas from the same line as the BBQ, and getting it's gas about 15" before the first ball valve and 30" before heading down into the ground to head out to the BBQ.

^^^Where is the manifold? How do you know that the HWH and grill share the same line?

This is what a manifold looks like:

quote:

Originally posted by Skins2881:
^^^Where is the manifold? How do you know that the HWH and grill share the same line?

This is what a manifold looks like:

No idea. Likely in the attic. I don't so attics. Likely end up with my leg through the ceiling

I opened up a hole in the drywall and can see where the line splits off for the hot water heater. The line that splits off goes a few inches as an iron pipe, hits a ball valve, then a flexible line to the water heater. The path that continues past the water heater goes about 15 inches, makes a 90 turn, goes out the exterior wall, does another 90 down towards the ground, goes a couple of inches, hits a valve (yellow) then goes about 12-15" into the ground (presumably heading across the back yard to the BBQ).