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Bill P.
Bill P., HVAC Mechanic
Category: HVAC
Satisfied Customers: 338
Experience:  Oil / Gas / A/C / Hydronics
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light on my lennox elite series furnace flashing green -- says

Resolved Question:

light on my lennox elite series furnace flashing green -- says "flame low" and furnace won't kick in.

I accidentally said i would take a text message to my phone.   please ignore that -- i don't have texting!

Submitted: 6 years ago.
Category: HVAC
Expert:  Bill P. replied 6 years ago.

Bill P. :

Hi there

Customer :

hi

Bill P. :

sounds like your flame sensor may need cleaning

Customer :

where is it located?

Bill P. :

it is a steel rod stuck in the flame on the end of one of the burners, mounted with porcelain

Bill P. :

it will have ONE wire going to it

Bill P. :

not to be confused with the igniter, which has 2 wires going to it, steer clear of it, its quite brittle

Bill P. :

It can be cleaned with steel wool or scotchbrite

Customer :

my brother in law is helping me-- he located it -- now he is removing it

Bill P. :

usually held on by one screw..

Bill P. :

some models of lennox are quite hard to get at, but i think yours may be easy enough

Bill P. :

does it look oxidized? white crusty etc..

Customer :

he went to look for a socket so he can remove it

Bill P. :

hmm socket? maybe hard to reach, it may be a 1/4 inch socket

Customer :

that's what it looks like -- he's getting close

Bill P. :

no hurry..

Customer :

he's getting a couple other screws off to get to the part

Customer :

we cleaned an l shaped metal rod -- is that the correct part?

Customer :

L shaped, not I shaped

Bill P. :

http://midwestapplianceparts.com/images/B1172606.jpg

Customer :

it didn't look white or crusty

Bill P. :

something like that but it could be in a L shape

Customer :

ours looks just like that but the rod is an L shape -- he's putting it back in now

Bill P. :

ok, sometimes they dont look all that dirty but its enough to through it off..

Bill P. :

also make sure any grounds (green wires) are screwed on securely and no corrosion, there might be one near or mounted on the burner assembly itself

Customer :

everything back where it was and still flashing green

Customer :

sounds like it is starting and then stops in a couple seconds

Bill P. :

turn the power off to the unit for 15 seconds and back on

Customer :

tried that -- same thing with flashing green

Bill P. :

can you get me the model number of the furnace? should be inside somwhere..

Customer :

looking..... what kind of number is XXXXX?

Bill P. :

turn your thermostat down or off, then turn power off, leave off for 1 minute, power it back up then turn the thermostat back up to try and bring it on

Bill P. :

it should be inside on the walls somwhere, on a big white sticker

Bill P. :

usually near the top of that sticker

Customer :

97L4801 -- is that it?

Bill P. :

dont think so, that could be a serial number or something..

Bill P. :

it may start with a G.. not not for sure

Customer :

G23Q3-50-6

Bill P. :

thats it thanks

Customer :

flame on!!!!!!!!!!!!!!!!!!!!!!1

Bill P. :

and staying on?

Customer :

so far so good

Bill P. :

what will happen if it doesnt sense the flame right, is, it will try 3 times, each time lighting for a few seconds, but then it goes off on safety, thinking that there is no flame

Customer :

we're listening and watching to see if it will stay .... give us a minute, please

Bill P. :

yep..

Customer :

now it appears to be blowing but no flame -- it went out and it's not re-firing

Bill P. :

and what is the code flashing?

Bill P. :

the diagnostic code?

Bill P. :

how hot are the ducts?

Customer :

double green

Customer :

ducts are not hot, flame was on for about 60 seconds

Customer :

thermostate showed increase of 1 degree when it was briefly on

Bill P. :

double green flashing?

Customer :

yes

Bill P. :

give me a sec

Customer :

ok

Customer :

bob hit reset on the thermostat and the flame ignited, we'll wait and see again

Bill P. :

hows the batterys in the stat? changed lately?

Customer :

yes, from a brand new package. good question, tho. my thermo doesn't show low battery -- the only way i can tell is that the numbers for the temp setting don't show. but in general, low battery can cause odd problems?

Bill P. :

yes it can, not the low flame signal one though

Bill P. :

be sure to use good alkaline batteries

Customer :

it's still running

Bill P. :

is your air filter clean?

Customer :

bob wants me to ask if he should replace that part or was cleaning it sufficient?

Bill P. :

cleaning is generally sufficient, as long as the porcelain was intact, no cracks etc..

Bill P. :

it should be cleaned once a year

Bill P. :

is your air filter clean?

Customer :

air filter is clean

Customer :

i love you

Customer :

i will give you $10 tip -- so $25, okay?

Customer :

brother in law wants to know if you're married :-)

Bill P. :

haha yes I am married lol

Customer :

damn it! LOL

Bill P. :

funny the thermostat went out there..maybe a fluke, put fresh batteries in anyway to be sure

Bill P. :

Let me know if it acts up any more

Customer :

OK

Bill P. :

http://www.cozyparts.com/Lennox-Parts/forum/Lennox_service_manual/Furnaces/G23_G23X_08-01-2001.pdf

Customer :

now do i hit Reply to "pay" you?

Bill P. :

that is the link to your manual, it has a good troubleshooting list of diagnostic codes etc..might come in handy

Bill P. :

I guess thats how it works yep

Customer :

Thank you from the bottom of my heart -- we were freezing!!!

Bill P. :

Glad to help :)

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