Gas furnace update....

[Absent Minded Farmer]

Well, I didn't do anything wrong at least. All the maintenance I did was done the way it should be. No issue with changing out the igniter, either. So, it seems someone from the high falutin local big time HVAC company we called last year, this time, was messing with the flow set screw on the regulator in the furnace. The small time service guy who worked on it today, the same guy who put the furnace in several years ago, told me that those regulators are identical between several manufacturers. When he sets that screw for a furnace hooked up to natural gas, he always puts the notch in the screw perfectly vertical. Puts a little scratch in it at the top next to the notch. He found the scratch pointing at about 5 o'clock. Set it back to where it should be & we have heat again.

What I'd like to know is, is it possible that the screw was set low enough to cause the regulator to starve out & not light the furnace when there's a large demand on the system & the pressure drops? Seems like a shiesty move by a major HVAC company that would want to keep coming back for a routine service call to keep their pockets fat. Kind of like a jack leg mechanic pouring oil on an engine to get you to pay for something that didn't need to be fixed in the first place.

Mike

 

[DoubleO7]

Your suspension is possible.
The regulator on the furnace may have been on the low side.
But then the regulator out at the meter might also be on the low side of flow and pressure.
It might be that there was a recent change in the line pressure upstream of the regulator on the meter.
Due to more users of NG being added to the same distribution line you are on. Or volume used going up.

When we were building industrial aluminum melting furnace gas combustion systems, we had to know what the incoming gas pressure and line size was at furnace location.
With that info we could chose the right size regulator with the correct size spring and correct size orifice in order for proper operation.

 

[optiman]

here are a few frauds I have come across. the fraud occurs because the customer trusts the service guy.
Hell they advertise it. When it comes to furances short out the gas valve when the thermo coupler is at fault. eyeglasses big time when you have vsp, eyemed or davis. some providers will collect bigger copayments for options that are also available at a lesser cost or no cost. they just don t tell you. why buy extra for scratch warranty for two years when your insurance covers lenses every year and than before the time is up go in and have them replaced. I could go on but don t have the time.did you know that single vision plastic lenses are $1.20 for a pair. yea I got a bone to pick and I do encourage to get your eyewear online. same machines make them

 

[wore out]

WHY would any professional gas furnace service man look at "scratch marks" to determine where the gas pressure adjusting screw should be set?

The proper thing to do would be to verify (using a manometer) that the incoming gas pressure is within the range specified on the furnace rating plate, then set the regulated manifold pressure to "spec.", also using a manometer.

 

[Absent Minded Farmer]

The scratch mark is there to see if anyone futzes with it. If nobody touched it, it may be a fault in the regulator.

I would guess he doesn't use a manometer because he's been setting these things up for a long time. I would use one as I have no experience in the matter.

Mike

 

[Absent Minded Farmer]

I certainly don't have anymore trust in the big HVAC company in the area. As for my glasses, the lenses are manufactured in Germany by Zeiss & sent here to be polished to the right prescription. Medicare did not cover these lenses. All out of pocket. The frames were covered, however. It's good to know about the plastic lenses, though.

Mike

 

[Absent Minded Farmer]

Shoot. I forgot to ask about the regulator out by the meter. Just curious if he knew anything about the spring. not sure though if that's something
the gas company takes care of or if it's up to the owner.

Mike

 

[M-MAN]

Marking the valve so you can tell if someone has moved it is reasonable. What isn't reasonable is for a tech to adjust it without testing the pressure. That is dumb and dangerous. There is no reason to mess with that valve after the initial setting. It doesn't change.

No I don't think anyone deliberately sabatoged your furnace to get more service calls. What I do think is someone got lazy and took shortcuts they shouldn't have. Changing the pressure to overcome dirty orfices or spider webs in the burner tubes isn't the proper way to do things. Normal procedure is to clean both when doing the annual check up. Do that and you won't have to touch the valve.

 

[miangus]

The gas company is responsible for their equipment and get pretty grumpy if you mess with it. The service guy should have checked the inlet pressure if he thought that was an issue.. Should be .25 PSIG.

 

[sotxbill]

Isn't setting/checking the furnace for a clean burn,,, part of normal service????? It's in the instructions of every furnace i have ever seen.

 

[DoubleO7]

(quoted from post at 03:18:00 01/08/21) Shoot. I forgot to ask about the regulator out by the meter. Just curious if he knew anything about the spring. not sure though if that's something
the gas company takes care of or if it's up to the owner.

Mike

Most gas companys claim everything from meter outlet and upstream is their property and hands off to anyone but them.
In some cases everything upstream of where gas enters the building.