Natural gas pressure - range not hot enough

[Pktaske]

Just bought a new dent and scratch KitchenAide range. $2400 normally. New house had an old GE that we thought was 'worn out' (not a lot of juice in the output).

New range took like 25 min to preheat to 325 and sometimes the oven burners took a while to ignite, if at all. Top burners also under-performing. Gas company came out to check outside pressure of NG into the house, said it was good. Called manufacturer and they replaced regulator on range under warranty. Still no good.

I've got a 50' run in the basement of what looks like 1" (?) black pipe to a 1/2" reducer T where it makes its final ~3' run to range. I also have a gas dryer off the same run that seems to be working fine. Range was checked and is set up for NG.

This is summer so the range is the only appliance pulling demand 95% of the time. Water heater and dryer rarely on. My gas bill was $18 dollars last month.

Looking back, the underperformed GE was probably suffering from what I assume now is a low pressure problem(?) How do I diagnose and fix this?

Note:
-The gas company guy actually came into the house and checked out the flexible gas hose to the range which I had disconnected. He turned the valve on quickly and said 'it whistled' so pressure was ok. (???)

-House was previously on Propane.

-I moved the range to the laundry room which shares the wall and gas connection with the kitchen. Definitely an improvement but I still find it underwhelming.

 

[Pktaske]

Pic

 

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[Jeff H Young]

you might be close to on track but I don't think a gas oven not functioning properly on 50 ft of 1 inch and 1/2 inch branch 3 ft nope not buying that . but with nothing else running if the pressure is within spec. than I might consider a blockage in the piping I've had the slip on caps for shipping get inside a pipe I've seen pipes filled with mud .
I don't have proper equipment to test. I'd want to know how much gas will flow? Bad Regulator at meter? but I'm not buying that pressure needs jacking up unless there is a cause and think you should find the cause

 

[Breplum]

Most any plumber can check the pressure at the appliance. A manometer is the tool. Seven inches water column is what we expect to see on natural gas. Past that, it is not plumbing, much.
HOWEVER
On upslope homes and weird situations, we have, in multiple cases, run into situation where water has condensed/precipitated out of the gas causing a severely impaired gas flow due to the trapped water.
It is tricky but we've been able to get the water out and completely solve the gas flow problem. When I've spoken to gas company field techs about this, none have much experience, so it is rarely suspected.

 

[Jadnashua]

Static pressure would be essentially the same anywhere along the line, but dynamic pressure will depend on how much volume is requested, the length of the pipe, and the diameter. If there's a restriction, you won't get enough volume. It could be rusted pipe, something lodged in there, water, or who knows.

 

[Pktaske]

All great comments. I guess the first step is pressure testing at the water heater, range and dryer.

Crazy thing, the house is on gas heat. 2 zone (basement and attic). 2900 sqft. Was perfectly warm during our winter home inspection. Those things need a whole lot more btu's than a range so incoming pressure should be ok, right??

 

[John Gayewski]

You need to run the range with a manometer hooked onto the flex line and a tee. That way you can see the pressure change while the oven runs. If it drops below 2" or 3" (look at the gas regulator for its minimum) wc then there's a problem with the line somewhere.

 

[Jeff H Young]

You need to run the range with a manometer hooked onto the flex line and a tee. That way you can see the pressure change while the oven runs. If it drops below 2" or 3" (look at the gas regulator for its minimum) wc then there's a problem with the line somewhere.

There you go ! the static lets you know if pressure is correct a running test shows obstruction. All this time I never used or seen used a manometer for gas .
I sure don't see pipe size as issue

 

[Plumber69]

Just bought a new dent and scratch KitchenAide range. $2400 normally. New house had an old GE that we thought was 'worn out' (not a lot of juice in the output).

New range took like 25 min to preheat to 325 and sometimes the oven burners took a while to ignite, if at all. Top burners also under-performing. Gas company came out to check outside pressure of NG into the house, said it was good. Called manufacturer and they replaced regulator on range under warranty. Still no good.

I've got a 50' run in the basement of what looks like 1" (?) black pipe to a 1/2" reducer T where it makes its final ~3' run to range. I also have a gas dryer off the same run that seems to be working fine. Range was checked and is set up for NG.

This is summer so the range is the only appliance pulling demand 95% of the time. Water heater and dryer rarely on. My gas bill was $18 dollars last month.

Looking back, the underperformed GE was probably suffering from what I assume now is a low pressure problem(?) How do I diagnose and fix this?

Note:
-The gas company guy actually came into the house and checked out the flexible gas hose to the range which I had disconnected. He turned the valve on quickly and said 'it whistled' so pressure was ok. (???)

-House was previously on Propane.

-I moved the range to the laundry room which shares the wall and gas connection with the kitchen. Definitely an improvement but I still find it underwhelming.

Was the new regulator converted to NG

 

[Plumber69]

Was the new regulator converted to NG

The office holes are smaller on LP I'm suspicious of it all the burners did get converted to NG

 

[Tuttles Revenge]

Also propane can be much much smaller pipe diameter than NG if the regulators were all placed at the appliance.

OP states

I've got a 50' run in the basement of what looks like 1" (?) black pipe to a 1/2" reducer T

Need to verify actual size and distance of the pipe to know if its sized properly. 1/2" iron pipe has a near 7/8" outside diameter.

But def run tests as John G states.

 

[Pktaske]

Manometer and 'T' being delivered Thu.

 

[Jeff H Young]

Manometer and 'T' being delivered Thu.

Great keep us posted on findings. Im leaning toward a restriction, unrelated to pipe sizing. of cource it is true that natural requires bigger pipe and orifices when supplied in common pressures

 

[John Gayewski]

I'm leaning toward the oven itself being the problem.

 

[Reach4]

I was surprised that a range designed for regular 7-inch water column natural gas would have its own regulator.

 

[Jeff H Young]

never seen a range without a regulator havent installed a new one lately.

 

[Jeff H Young]

I'm leaning toward the oven itself being the problem.

Probebly right , but I thought he said he replaced range and same problem.

 

[Reach4]

never seen a range without a regulator havent installed a new one lately.

Now I know.

Pktaske: note that yellow PTFE ("Teflon") tape is built to a higher standard that is suitable for gas. Pipe dope is good too. See https://terrylove.com/forums/index.php?threads/pipe-dope-on-all-threads-for-gas-valve.91782/

If it turns out that the gas piping is too small for the job, you could ask your gas company what it would take to deliver a higher pressure to your house -- maybe 2 psi. If you get that, each appliance gets its own regulator.

If you wanted to be able to power a natural gas Generac whole house generator, that would make gas supply much easier. Some gas companies will do it, and others will not.

 

[Jeff H Young]

medium pressure inside a home frowned upon here . Ive never seen it on a house either.

Installing a natural gas generator is whole differant issue usualy its installed near meter or a dedicated line is run like we do for a pool heater
I suppose if you wanted to use a 1/2 inch bbq stub and you were 100 ft away from the meter on other side of house converting to medium pressure might be an option , its not just gas company its your city or county involved as well

 

[Reach4]

At least one California supplier supports 2 psi at least for new residential construction. https://www.socalgas.com/for-your-business/builder-services/elevated-pressure I don't know if they support retrofits. It should be easy enough in most areas, because the regulator at the home is supplied by pressure much higher than 2 psi.

It does seem to be a lot less available than I think it should be.