Troubleshooting A Goodman Furnace - HVAC - Contractor Talk

Troubleshooting A Goodman Furnace

 
Thread Tools Search this Thread Display Modes
Old 11-09-2010, 05:30 PM   #1
Registered User
 
azfats's Avatar
 
Trade: Refrigeration
Join Date: Nov 2010
Posts: 3
Rewards Points: 10

Troubleshooting A Goodman Furnace


New guy around here, looking for a little help.

I'm a pro reefer tech/food equipment tech struggling to get my mother's furnace going. It's a fairly new Goodman GKS9090.

It locks out on a single flash error code, no ignition. The blower comes on, the igniter lights up but I get no ignition. I have verified that there is gas to the unit and I see 27v at the gas valve but no flame.

I don't know much about domestic HVAC so I'm wondering if the sequence is correct. the blower comes on for about 15~20 secs, then the igniter lights up but the the gas valve only gets juice about 5 seconds later, and only for about 2 or 3 secs, then it shuts down. I don't know if this is correct, it doesn't seem like that is long enough to fire up and prove a flame to the sensor. There is no port upstream of the valve to hook up my manometer so I'm not sure if the valve is actually opening for the breif time it gets juice.

Trying to figure out if I have a bad board, a bad GV, or something else. Would like to find a link to Goodman technical info.
azfats is offline  

Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ContractorTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

   

Advertisement

 

Old 11-09-2010, 06:45 PM   #2
Pro
 
Electric_Light's Avatar
 
Trade: student again
Join Date: Nov 2007
Location: helicopter
Posts: 853
Rewards Points: 500

Re: Troubleshooting A Goodman Furnace


The board usually won't even allow the igniter to fire up until draft induction is proven (pneumatic or centrifugal switch). It sounds like you are past that point. The blower you're talking about is probably the combustion blower, and 15-20 seconds is not unusual.
You said igniter lights up and voltage is applied to gas, but no flame... but you haven't said if gas is flowing.

If you're not getting flame at all and there is voltage at the gas valve, do you smell gas at the furnace? If there is gas at appliance(input side), and gas isn't flowing, its the gas valve, or clogged orifices.

Sounds like you're dealing with a hot surface direct ignition. An electrode in a flame acts like a diode and when an A/C voltage is applied, it is rectified. The control unit senses the rectified current to prove flame and gives a limited time frame before flame is proven or it shuts down, but if its not lighting up at all, this probably isn't it.

If you've got plugged orifice preventing the sensor from touching the flame, or the rod is dirty, it won't see the current. You should see a sensing electrode somewhere in the flame. Clean it with a wire brush. If the ceramic insulation is damaged, it needs to be replaced.

You will always smell gas from failed ignition attempt.

Advertisement


Last edited by Electric_Light; 11-09-2010 at 06:57 PM.
Electric_Light is offline  
Old 11-09-2010, 07:25 PM   #3
Pro
 
beenthere's Avatar
 
Trade: HVAC
Join Date: Mar 2009
Posts: 2,440
Rewards Points: 1,186

Re: Troubleshooting A Goodman Furnace


Isn't that a Gemini gas valve?

look for a small hex screw on a raised port. You only turn the hex loose, you don't remove it. You put your hose over the port with the hex screw loose.
beenthere is offline  


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Goodman Gas furnace propertyone HVAC 3 02-22-2009 07:36 AM
Goodman 80% furnace brand new won't start Hguy HVAC 21 03-28-2008 11:05 PM
Goodman Furnace stopped running ColdInCO HVAC 1 01-22-2008 10:36 PM
Goodman 80% furnace won't start with side cover on rlelliott HVAC 7 12-09-2007 12:42 AM
Goodman furnace rservices HVAC 3 10-26-2007 09:26 PM

Join Now... It's Fast and FREE!

I am a professional contractor
I am a DIY Homeowner
Drywall Talk is for
PROFESSIONAL CONTRACTORS ONLY!

At DrywallTalk.com we cater exlusivly to professional contractors who make their living as a contractor. Knowing that many homeowners and DIYers are looking for a community to call home, we've created www.DIYChatroom.com DIY Chatroom is full of helpful advices and perfect for DIY homeowners.

Redirecing in 10 seconds
No Thanks
terms of service

Already Have an Account?