Original message
| Civickid
 |  "g14 wont start"
, posted Fri 25 Jan 00:56  
I have a G14 Lennox pulse furnace with Johnson controls ignition. The furnace wont start. The purge fan comes on, then after 35 seconds or so, there is a click and a electrical buzzing sound that lasts 8 seconds. Then nothing. Checked my basics, I have 24V at the W terminal when heat is requested. There is 24V to the gas valve for 8 seconds after the 35 second wait. Anything guys and girls?
little help here
|
|
Replies:
|
| 341
| "Re(1):g14 wont start" , posted Fri 25 Jan 18:59
Have you verified you have gas? Did you get a flame signal at all.
You may have a bad ignition module that isn't reading the flame signal and causing a lockout.
Dirty gas flapper, dirty flame rod.
I would start there.
www.hvactechgroup.com
|
| | civickid
| "Re(2):g14 wont start" , posted Fri 25 Jan 21:17
I had a licensed tech come out, he verified gas pressure. He believes its the ignition control not producing spark. My only problem is the electrical buzzing sound i hear sounds like spark rapidly firing. Dont think he did a spark test.
little help here
|
| | northernfitter
| "Re(3):g14 wont start" , posted Sat 26 Jan 20:43:
The problem with the pulse is a lot of techs have no experience with them so they make a guess then run for the hills. It sounds like you have spark and its possible your gas flapper could be blocked, the gas valve is not being energized by the module, or the gas valve not working. Best of luck to you and make sure if you do call a tech on it that they are a lennox dealer and state that you have a pulse so that they send someone experienced on them.
edit: I just recalled that I have seen that Johnson module lose the connection internally for the spark and make all kinds of spark noise but there was no spark due to the module fault.
14years as a service tech in Ottawa and the valley. www.reliableheating.ca. For furnace manufacturer ratings go to
http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/gas-furnaces/furnaces-repair-history-205/overview/index.htm?resultPageIndex=1&resultIndex=1&searchTerm=furnace
[this message was edited by northernfitter on Sat 26 Jan 20:46] |
| | marchvac
| "Re(4):g14 wont start" , posted Sun 27 Jan 11:41
Just replaced that Johnson module last week. That module cost a fortune might want to start thinking about a new furnace. Don't get me wrong that is an excellent furnace but if you don't get the rite tech to fix it, it is going to cost a you a fortune. Northern is correct I opened the plastic to check the board after I replaced it and there was one burnt spot inside.
Be careful sometimes you don't get a second chance
|
| | civickid
| "Re(5):g14 wont start" , posted Sun 27 Jan 20:39
I had another tech come out and take a look. I was with him this time. He verified gas pressure, gas valve be commanded by the module, purge blower, and spark. The flame signal was 0 micro amps, he checked continuity of the wire, checked out good. How many ohms should the actual flame sensor have. Does it need to ground thru the furnace.
little help here
|
| | marchvac
| "Re(6):g14 wont start" , posted Sun 27 Jan 21:18
The flame sensor measures microamps.
Watsco is 3 to 5 microamps
Gas energy control is 25 to 35 microamps
Lennox GC-1 is 18 to 35 microamps
Be careful sometimes you don't get a second chance
|
| | civickid
| "Re(7):g14 wont start" , posted Sun 27 Jan 21:46
and if I have a johnson control module?
little help here
|
| | marchvac
| "Re(8):g14 wont start" , posted Mon 28 Jan 05:39:
What is the model# of the board.
The Johnson GC3 should have between .6 and .9 when there is flame signal. If it is not lighting then it is a good possibility that it is that board.
Be careful sometimes you don't get a second chance
[this message was edited by marchvac on Mon 28 Jan 11:03] |
| | civickid
| "Re(9):g14 wont start" , posted Mon 28 Jan 13:54
Hey Marchvac, I sent you an email to your address you have in your profile.
little help here
|
| | northernfitter
| "Re(9):g14 wont start" , posted Mon 28 Jan 08:21
0mA means there is no ignition happening at all. A faulty flame sensor would still give some reading. It sounds like the original technician that diagnosed it may have been right. Did the technician that was there not make any recommendations?
14years as a service tech in Ottawa and the valley. www.reliableheating.ca. For furnace manufacturer ratings go to
http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/gas-furnaces/furnaces-repair-history-205/overview/index.htm?resultPageIndex=1&resultIndex=1&searchTerm=furnace
|
|
|
