Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 03-29-2009, 11:15 AM   #16
Newbie
 
Join Date: Mar 2009
Posts: 1
Share |
Default

Lennox Furnace problems


Hi all...I see all the posts to clean the flame sensor with steel wool or sandpaper, but how do I find it? Is it in the top or bottom panel? Is it exposed or do I need to remove something else to get to it? I looked at the user manual but it's not "called out" in the drawing...can someone please help? I am not that handy, but I can certainly clean something if I can find it.

I am new to this chat board so I'll look back later or if someone can email me at mattsiegel@yahoo.com?

msieg is offline   Reply With Quote
Old 03-29-2009, 11:46 AM   #17
Hvac Pro
 
Join Date: Nov 2008
Location: Winnipeg, Canada
Posts: 9,256
Default

Lennox Furnace problems


I am a Lennox tech and it is VERY difficult to get at that sensor. Very good chance you will break it. It is inside the burner box and is twisted in front of one of the burners. I would recommend you get a Lennox tech to do a PM on the furnace and watch him. Next time you may want to DIY. Very important that the drain hose from the exhaust pipe rubber boot be removed and cleaned/flushed with hot water.
yuri is offline   Reply With Quote
Old 03-28-2010, 11:10 AM   #18
Newbie
 
CutOnce's Avatar
 
Join Date: Mar 2010
Posts: 1
Default

Lennox Furnace problems


Quote:
Originally Posted by chrisbatto View Post
Hi All,

My Dad and I have the same G20 Whisper heat furnaces Both 15 yrs old.

His was really bad, failing to operate 2-3 times daily between Christmas and New Year. We had to turn off the power and restart again otherwise the fan would just run continuously with cold air.

Mine had worked with just a clean up of the flame sensor area last year (brass brush and steel wool) but it had still acted up once since then.

You can't rest at night with these things going on.

I replaced the Module with the Honeywell replacement ( From Amre Supply here in Canada). And a Flame Sensor too. (About $210 total)

I replaced both parts on my Dad's...now working like a Swiss clock and igniting very quickly.

To have peace of mind, I did mine too.

I would recommend this to anyone who has an older G20 furnace. My reviews of many websites tells me this is going to be a problem if it hasn't started already.

Yuri and Skip are right and thanks to you. as stated.... MAKE SURE you read the instructions very carefully and completely a few times before you start.... and then read again during the job.... If you don't... you will be in serious trouble.

To replace the flame sensor, you need to remove the cover panel above the damper flap (two small bolt) and you will need to disconnect the small aluminum? gas line from ahead of the Gas valve. I used a Brake line wrench to get even torque. (Shut of the gas at the valve!)

Then the two small bolts hold the whole thing onto a bracket inside the furnace. So remove these and fish the pipe out to replace the flame sensor in your lap or at a bench...just slides out and back in again.

Be careful of the wire routing and to not lose the grommets where the pipe and wires pass through the cover panel when you reassemble.

Test the gas fitting for leaks (twice if you are like me) by using soapy water and a kids paint brush.

Good luck

Chris
This was the best post i found on any site !! Great job and many thanks !! I am a carpenter and not so mech. inclined..... This whole operation took about 2 hours (for me ) , with cleanup and saftey checks ......... 3 days no Heat --- 2 hours and " WHISPER HEAT " !!!! Very happy and really wanted to say thanks ....Justin

Try out instructions by chrisbatto in this tread...
CutOnce is offline   Reply With Quote
Old 05-30-2010, 12:39 PM   #19
Newbie
 
Join Date: May 2010
Posts: 2
Default

Lennox Furnace problems


I purchased a 1993 home last year with the G20 furnace. It has the 30W33 igniter module installed (date unkown). For the past several months, the temperature is irratic. It will not come up to desired temperature. I have replaced the thermostat but this did not solve the issue.

The furnace ignites, blower starts, then the gas valve solenoid turns off. The blower continues to run, then the burners re-ignites. The furnace cycles through this until it stops all together. I am getting a 6+3 green flash and a 1 yellow flash.

I have cleaned the flame sensor as well as tested the microamp values. They both look good. Could it be that the 30W33 module is faulty?
jpryma is offline   Reply With Quote
Old 06-03-2010, 07:53 PM   #20
Newbie
 
Join Date: May 2010
Posts: 2
Thumbs up

Lennox Furnace problems


Quote:
Originally Posted by jpryma View Post
I purchased a 1993 home last year with the G20 furnace. It has the 30W33 igniter module installed (date unkown). For the past several months, the temperature is irratic. It will not come up to desired temperature. I have replaced the thermostat but this did not solve the issue.

The furnace ignites, blower starts, then the gas valve solenoid turns off. The blower continues to run, then the burners re-ignites. The furnace cycles through this until it stops all together. I am getting a 6+3 green flash and a 1 yellow flash.

I have cleaned the flame sensor as well as tested the microamp values. They both look good. Could it be that the 30W33 module is faulty?
Turns out that the jet orifice for the pilot light was getting plugged and not heating the sensor enough. I took the jet apart and gently opened the orifice. The sensor now glows red and furnace stays on. Hope this was it.
jpryma is offline   Reply With Quote
Old 11-19-2012, 05:41 PM   #21
Newbie
 
Join Date: Nov 2012
Posts: 1
Default

Lennox Furnace problems


After reading everyone's comments on the Lennox G20 Whisperheat ignition problems, here's my experience. My girlfriend's Whisperheat was going into fault mode about once a day with the start of the heating season last week. It had similar symptoms to those mentioned here: the furnace would stop igniting during a call for heat and would fault with the damper door open, sometimes not even lighting. Sometimes the main gas valve chattered as well when it did light. A reset of the system, by cycling the thermostat or flipping the furnace power switch off and on, would fix it for a while. The thermostat was giving the right signal to the terminal strip on the furnace circuit board. I did the following:

1) Snipped about 1/4" off the high voltage wire coming from the ignition control box to get a better connection on the spike and reinserted.

2) Cleaned flame sensor.

3) Checked to see that the pilot flame was touching the flame sensor.

The furnace was still not lighting reliably. A wiggle test of the spade terminals on the Johnson Controls g776rgd-11 box would consistently cause the main gas flow to cut out or prevent the unit from even lighting--sounded like bad connections in the ignition box, as others have mentioned.

With nothing to lose, I hacked into the Johnson Controls box to check out the solder connections. I drilled out the brass grommets to remove the back panel and removed the circuit board. Everything was covered in conformal coating, which came off with Goof Off and a toothbrush. I could then see the solder joints clearly. It looked like a few were cracked, particularly on the large leads on the two relays. I resoldered those joints, and all the others I felt safe soldering with a 35 W iron with a fairly large tip. I might touch up the surface mount components and microprocessor connections later with a smaller iron I have at home.

Anyway, I put the ignition box back together and in the furnace, and the furnace is working perfectly now. A wiggle test of the spade terminals has no effect on the furnace operating. I'll see how it goes in the next few days but it's looking good for the moment.
KeithG is offline   Reply With Quote
Old 11-19-2012, 06:45 PM   #22
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Default

Lennox Furnace problems


Folks looking this up later...most every G20 has developed cracks in the heat exchanger. They still run but should be red tagged at that point. The heat exchangers had a 20 year warranty,the date code is the third and fourth numbers in the serial number. If you have one it would be a good idea to get it inspected by a good hvac tech.

Marty S. is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Lennox Furnace G27M Series Unreliable operation: pressure switch or else? sheppard1977 HVAC 7 01-14-2013 05:42 PM
Problems with new furnace..Overheating, having to reset. Furnace too big? Tommy2 HVAC 41 12-01-2008 01:55 PM
New Cased Coil - Install to Furnace - PICTURES!! hartkem HVAC 39 11-18-2008 01:45 AM
furnace and or electrical problems tuasoi General DIY Discussions 4 11-29-2007 12:50 PM
Furnace Problems? Part 2 MCSE HVAC 9 11-30-2006 09:25 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.