Goodman Furnace Gas Valve Not Opening

[web...@hotmail.com]

Need help troubleshooting a new installation of a Goodman 70K btu 95%
efficiency two stage gas furnace (Model GMH950703BXA). Brand new.
Replaced old furnace with new. Unit ran fine for about 30 minutes and
then cycled itself off. No flashing diagnostic light until tried three
times and then single diagnostic to indicate three failures and that
gas not being delivered to burners.

Gas pressure fine.
Unit cycles on, blower runs, igniter heats up but after 15 seconds
igniter turns off because flame senses nothing. Not sure why it will
deliver gas to burners anymore. I checked the gas valve while running,
after igniter heats up, I can confirm valve does not open. I know
valve is not the broken because I took valve from another new unit and
still same results. In fact, tried replacing every part except the
combustion fan

The only thing I can think of is that we did not do the direct
venting. While testing, left air inlet as is and combutsion out was
vented to existing flue from old furnace (4" flexible tube).

If venting was the issue, wouldn't the unit at least burn for a time
and then cycle off ? Now cannot get any gas to be released by valve to
the burners. Tried turning off gas, shut off gas valve, shut off
electricity, and re-started everything again, but same results. Tried
4 or five more times.

Any suggestions would help.

[Speedy Jim]

You tried a gas valve out of another new unit?

Did you try another control board? (Maybe I missed that...)

Does the pressure sensor close after the inducer runs?

I gather this is some temporary setup with venting.
Don't see how that would affect it.

Is the electric service to the furnace control properly
Grounded AND is the polarity correct? (Wh Neutral, Blk Hot)
The control is very sensitive to those conditions.

Jim

[Stormin Mormon]

Is the gas valve getting power during the ignitor warm up? If so,
you likely have a bad gas valve. If not, I'd look for some notes
about how many amps the HSI draws. I worked on a unit that had a
HSI that glowed nicely, but the amperage draw was wrong. So, the
valve didn't think the HSI was working properly.

--

Christopher A. Young
You can't shout down a troll.
You have to starve them.
.

<web...@hotmail.com> wrote in message
news:1172006307.1...@m58g2000cwm.googlegroups.com...
: Need help troubleshooting a new installation of a Goodman 70K

:

[bubba...@yahoo.com]

I had the same problem a coupla months ago with my 90K BTU Goodman 95%
2-stage furnace. The contractor installed the brand new unit, and
after a couple of days the furnace started behaving just like yours
is. I called the guy, he came back, opened up the front cover, looked
inside, but wasn't sure what it was, but somehow got it to work. Over
the next few weeks the problem reoccurred a couple more times, once or
twice it self-healed, but then it wouldn't come back on, so I called
the guy again. The second time, hew finally figured it out, and was
able to fix it. The furnace has been working fine for 4-5 weeks now.
Here's what it turned out to be:

If you remove the front cover, there is a black rubber hose inside,
about 5/8" thick, that is used to remove H20 condesation (from the
exhaust) and drain it out of the furnace (thru a pvc pipe.) Well, this
black rubber hose was originally about 2+ft long(orig. length "out of
the box long"?), so it was "bent and curved" by 180 deg inside the
furnace when installed. There was a section of the hose that was
forming a slight U-shape, and it seems that some H20 was just sitting
in there instead of being drained out. That's at least how the guy
explained it to me, and he thought that, for some reason, was causing
the furnace to go into lockout.

Solution: The guy used a pair of scissors/cutters to trim the rubber
hose to the total length of maybe 10 " and ran it to the drainage
opening (on the right-hand side of the furnace) in a pretty much
straight, slanted line.

I hope I am explaining this clearly enough. I was getting so pissed
and frustrated for a few weeks, and wouldn't want anyone else to have
to go thru the same experience.

Please post an update as to whether you were able to get your furnace
fixed. I'll be very curious.

Good luck!

[Bob]

replying to bubbabubbs, Bob wrote:

I had exactly the same problem. I had tried everything I could think of.
Finally I called the installer since the furnace was only 3 years old and
still under parts warranty. He was scheduled to come out the next day.
While I was waiting for my wife to dress to go shopping I decided to do an
internet search and found this write-up. After reading about the
condensation drain hose problem it referred to, I went and squeezed the
hose over its entire length since it was very flexible. I then made sure
the hose had a drain slant (i.e., no dips) over its length. I estimate
that about a pint of water drained when I did this. After that I turned
on the furnace and it worked like a charm (at least so far). Thank you
for your input!

--

[hrho...@sbcglobal.net]

I wonder if the fact that the hose was clogged with water had somehow an effect on the overall air flow araoudn the unit and that was the problem.

[cl...@snyder.on.ca]

On Thu, 2 Jan 2014 20:41:13 -0800 (PST), "hrho...@sbcglobal.net"
<hrho...@sbcglobal.net> wrote:

>I wonder if the fact that the hose was clogged with water had somehow an effect on the overall air flow araoudn the unit and that was the problem.

Nope - it just threw the pressure balance off and one of the safety
"sail switches" would not turn off or on - preventing the unit from
firing.

[Art Todesco]

I had an Amana high efficiency unit in my previous house and it had a
similar problem. Because the combustion air on this model is from
inside the house (basement), it would pick up any dust, etc. in the air.
This particulate would then form what I referred to as slime balls
inside the drain tubes. There were 2 drains, one from the combustion
blower and one from the secondary heat exchanger. Usually the one from
the blower would clog. Initially it would start and run for a really
long time before combustion. Apparently, it would have to slug enough
water away from the blades in order to get enough negative pressure to
then allow the gas valve to open and start. If you let it go for a long
time, eventually, it would never open the gas valve; only the combustion
blower would run. I found that, because of the basement layout, when
the furnace was installed, I had to change the side where the drain was
located. So, there was a small coupling in the drain line. The line
was PVC with a short rubber hose on each end. Apparently, the roughness
inside the solid pipe, where the coupling was located, was enough to
catch the 'slime balls' and would build up until the line was clogged.
I changed out the drain line to a single clear plastic line. Now you
can actually see if a clog was forming. But, because there was no
roughness inside, it never did. However, I would periodically take out
the drains and clean any deposites with a small bottle brush and lots of
water.

[phlip...@gmail.com]

I just now went out and with a length of old hose shoved it down both exhaust pipes if you will and works like a dream.

[Tony Hwang]

What about condensate drain?
If in lpock out mode, it takes I think 2 hpours
before you can start the unit again. You can rest the unit
by turning power on/off. Control board has test point to ground to
test the unit. Tried or cleaned flame sensor?

[mako...@yahoo.com]

even those of us using Google Groups can see the dates of a post.

Mark

[THE COLONEL, Ph.D]

Call someone who knows what he/she's doing, sailor.

p.s. I have had Goodman furnaces here at Sunset Chateau for over thirty
years now. I'm on my second. Goodman products are every bit as good as the
way more expensive, highly over-advertised name brands like Trane, etc.
The extra money is for the name.
Yer welcome.

p.s. TRUMP FOR PRESIDENT. TAKE BACK AMERICA AND THROW OUT THE FUCKING
MINORITIES. YAY!

[Tom]

Bob ... You are a genius. How you determined that the problem was the hose filling up with water is beyond me. I disconnected the hose which had a slight "belly" in it, drained a half pint of liquid, shortened the length of the hose, and reconnected it... making sure it was on a continuous slant downhill the entire length. Furnace worked like a charm !
I was curious why the furnace worked all last winter but I figure it was initially installed in the dead of last winter when there was low humidity. the condensation never built up until I started it up this year. Thanks again. Tom

[Tony Hwang]

Our furnace is Carrier 96% model. No hose. Rigid PVC small dia.
pipes connected to AC evaporator pan drain then straight down to
drain in the basement floor. No such problem either on AC or
furnce. I bet the problem will recur unless you make sure same
standing water problem happens.

[prome...@yahoo.com]

2017 --- Installed a brand new Goodman Furnace/Central Air system last summer and had the SAME experience as you. I found this blog and fixed it. Thank everyone!

[ChuckE]

replying to bubbabubbs, ChuckE wrote:
Thanks for your posting. I was experiencing the same thing - the gas burners
would not kick on. This was just a few hours after they had done their annual
service check. Service came back out and he first said it must be the
thermostat since the furnace was working when he left. He then determined it
must be the gas line. Then the gas valve. Finally he got on the phone with his
head technician. He began checking everything he had already done. I step
inside the house to warm up and I googled and found your experience. I went
back outside and the technician, still on the phone, was discussing going
through all the wiring to find the problem. I reached up and gently lifted the
hose and it began to drain. The tech was heading back to his truck for more
tools when I flipped on the power switch and the furnace kicked on. It was so
funny when I yelled back to the tech that I had fixed the furnace. He hung up
the phone and came to see what I was talking about. In the end the tech
thanked me and said I saved him a lot of time and trouble pulling the wiring
apart to test. He then said he learned something today. He learned that he
should google things first. He did get the hose adjusted so it drains properly
and all is well.

--
for full context, visit https://www.homeownershub.com/maintenance/goodman-furnace-gas-valve-not-opening-197009-.htm

[trader_4]

The root cause of this problem is very likely that it was not installed
correctly. Gas furnaces are typically shipped so that the venting and
draining can be done on either side. So the hoses are shipped longer,
so that if needed, it can be switched to the other side. I think my
hose was unattached with instructions to cut it to the required length.
I bet some installers don't cut it, or don't route it correctly, etc.
In your case, the service guy probably moved it while he was doing his
other work, creating a situation where it won't drain. And I'd say
his problem isn't that he needed the internet, it's that he doesn't
understand the basic operation and how to diagnose. Doesn't that
furnace have blinking LEDs and codes on the door to show what the problem is?

[Tekkie®]

ChuckE posted for all of us...

Reading your post was draining to my soul.
--
Tekkie

[Bob]

replying to Stormin Mormon, Bob wrote:
I am having this same problem. Replaced the circuit board and wiring harness
to no avail. I was told by several HVAC techs that the circuit board receives
no feedback from the HSI. I changed out the HSI. The HSI does glow but will
not fire on the first attempt......sometimes it does. It is not the rollout
switches because I checked for voltage straight out of the board before the
switches. No 24vac until the second lighting attempt. Please help, this
problem is driving me crazy

[trader_4]

If the valve solenoid is shorting out, the board could be trying to put out 24v, but can't raise the voltage. Still you'd think you would see some voltage at the solenoid. Could also be a pressure switch, but then you wouldn't think the igniter would glow. What code is the board flashing when it fails?

[Tekkie®]

Bob posted for all of us...

Hey Bob, Stormy is in the great HVAC system in the sky.

--
Tekkie

[Old retired sparky local#176]

replying to Stormin Mormon, Old retired sparky local#176 wrote:
It' the pressure switch to secondary heat exchanger and drain. Changed one
yesterday, no flash codes, but try fused jumper on the two wire connectors .
Furnace was GMH950703BXAF. Won't hurt to blow into the rubber tube to try
first if secondary exchanger drain is blocked it will flood and not let it
open the gas valve. There is two, one is -0.95 W.C. for the ID blower, the
other one on left is for the secondary exchanger drain at-0.10W.C. It's
sometimes called the upper door switch! TRY IT.

[Old retired sparky local#176]

replying to Bob, Old retired sparky local#176 wrote:
The HSI have to fall with-in a certain ampere rating. Some get weak some have
very small cracks, but either way they do not get hot enough . They can't tell
the temp. with anything but how much current it's pulling.

[Old retired sparky local#176]

replying to trader_4, Old retired sparky local#176 wrote:
Pull the connector from the valve and try to read voltage during the cycle.
Lower blower door switch should be closed and upper door PS needs to be
jumped with a fused jumper. Is it direct vent to outside with both intake air
and exhaust. Not having the upper door on messes with the switch. It's only
-0.10 W.C. and the ID blower is only -0.95 W.C." that's not much!

[trader_4]

On Saturday, December 1, 2018 at 10:14:08 AM UTC-5, Old retired sparky local#176 wrote:
> replying to trader_4, Old retired sparky local#176 wrote:
> Pull the connector from the valve and try to read voltage during the cycle.
> Lower blower door switch should be closed and upper door PS needs to be
> jumped with a fused jumper.

That's a good point, if he's going to test for voltage at the gas valve
when it should be there, he needs to make sure the door safety switches
are closed or bypassed.

[Clare Snyder]

On Sat, 01 Dec 2018 15:14:05 GMT, Old retired sparky local#176
<caedfaa9ed1216d60ef...@example.com> wrote:

>replying to trader_4, Old retired sparky local#176 wrote:
>Pull the connector from the valve and try to read voltage during the cycle.
>Lower blower door switch should be closed and upper door PS needs to be
>jumped with a fused jumper. Is it direct vent to outside with both intake air
>and exhaust. Not having the upper door on messes with the switch. It's only
>-0.10 W.C. and the ID blower is only -0.95 W.C." that's not much!

Dead thread guys, Stormy's been pushing up daisies for about 2 years
already.

[trader_4]

I guess you missed the part from the guy who just posted:

"I'm having the same problem"


Not surprised though.

[Cameron]

replying to Old retired sparky local#176, Cameron wrote:
Hi, I really need some help! Having the same problem as described in the
thread. The furnace ignites but the burners will not work. Had the gas valve
replaced and it worked for a month. Then same issue. Replaced the gas valve
again and good for a month. Now again same issue. Tried to squeeze the black
hoses manually and no issues. I've had 2 very good techs come and they only
fixed temporarily. Please if anyone can help, I'd be very very thankful. This
is painfully frustrating!

Ps. It's a Goodman 95% gmh950703baxf.

[Cameron]

replying to Old retired sparky local#176, Cameron wrote:
Hi, I really need some help! Having the same problem as described in the
thread. The furnace ignites but the burners will not work. Had the gas valve
replaced and it worked for a month. Then same issue. Replaced the gas valve
again and good for a month. Now again same issue. Tried to squeeze the black
hoses manually and no issues. I've had 2 very good techs come and they only
fixed temporarily. Please if anyone can help, I'd be very very thankful. This
is painfully frustrating!

Ps. It's a Goodman 95% gmh950703baxf.

[trader_4]

Put a meter on the gas valve and verify that it has ~24V AC on it when
it's supposed to open. It it does and gas doesn't flow, then it's
either the valve or a problem with the gas supply. If there isn't 24V
there, then it's a problem with the control board, a sensor or wiring
and connection. Most likely not a sensor, because AFAIK furnaces won't
light up the igniter if a sensor is saying no-go. If the valve is kaput
again, has anyone investigated the failed ones to figure out why they
failed? Any chance there is debris in the gas lines? Does it have
a sediment trap near where it enters the furnace? A sediment trap is
a short piece of pipe with a capped end that goes down off a tee at the
appliance. It's there to catch any crap instead of it going into the
appliance.

[Ken]

I have a furnace with a two stage valve. At first it lights a small
flame and after the flame is detected, it opens the valve for full
ignition. Since there are only two contacts across the coil, does it
first apply something less than 24 volts in order to do the first stage
of ignition? Perhaps the OP has a failure of the full voltage being
applied to the coil? Knowing what the model of the valve being used
would be helpful.

[trader_4]

IDK how that type works, it's a good question. I would not call that a
two stage valve though. Two stage furnaces have a high and low heat
output capability and by calling it two stages it can confuse it with
that. What you're talking about is a type of intermittent
pilot light, where it lights a pilot light, then turns on the gas.
Mine I don't think does that, it has a hot surface igniter and I think
it just gets that hot, then turns on the burner gas.

[Ken]

"Slow opening" is probably the correct term rather than "Two stage." I
have a furnace that also uses an igniter rather than a pilot light. The
way it works is to first allow only a small amount of gas out of the
valve, and if the igniter is sensed to have started a flame under this
condition, then it opens the full amount of gas. (For what it is worth,
the ignition of the starting flame must do so within a designated time
frame. If it does not, the cycle starts over for up to three attempts.
If it fails after three attempts, it shuts the furnace down.) I am not
sure exactly how the valve achieves this since it only has two terminals
for the valve coil. Perhaps it applies a lessor voltage at first, say
12 volts. Then if it senses the flame present, the voltage applied
could be raised to 24 volts?

Like I said, I am not a HVAC person. I am just suggesting that if the
proper voltage is not consistently being applied, that could explain
what appears to be a failing gas valve. Below is a link for such a valve:

https://keithspecialty.com/k/Honeywell-VR8205H1003.htm

[agv...@gmail.com]

I had the same issue but the air hose coming out of the ducting in my furnace was clogged after blowing in it a few times the chunk finally came out, thanks to this post, was looking for hours thanks

[Richard Y]

On Friday, February 23, 2007 at 4:59:09 PM UTC-5, bubba...@yahoo.com wrote:

> On Feb 20, 2:18 pm, web...@hotmail.com wrote:
> > Need help troubleshooting a new installation of a Goodman 70K btu 95%
> > efficiency two stage gas furnace (Model GMH950703BXA). Brand new.
> > Replaced old furnace with new. Unit ran fine for about 30 minutes and
> > then cycled itself off. No flashing diagnostic light until tried three
> > times and then single diagnostic to indicate three failures and that
> > gas not being delivered to burners.
> >
> > Gas pressure fine.
> > Unit cycles on, blower runs, igniter heats up but after 15 seconds
> > igniter turns off because flame senses nothing. Not sure why it will
> > deliver gas to burners anymore. I checked the gas valve while running,
> > after igniter heats up, I can confirm valve does not open. I know
> > valve is not the broken because I took valve from another new unit and
> > still same results. In fact, tried replacing every part except the
> > combustion fan
> >
> > The only thing I can think of is that we did not do the direct
> > venting. While testing, left air inlet as is and combutsion out was
> > vented to existing flue from old furnace (4" flexible tube).
> >
> > If venting was the issue, wouldn't the unit at least burn for a time
> > and then cycle off ? Now cannot get any gas to be released by valve to
> > the burners. Tried turning off gas, shut off gas valve, shut off
> > electricity, and re-started everything again, but same results. Tried
> > 4 or five more times.
> >
> > Any suggestions would help.

Thank you to Bubba for this solution! Even the heating company tech couldn't solve the problem... Still solving the issue in 2020!!