Amana pilot lights, then goes out


  #1  
Old 02-09-07, 12:51 AM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Amana pilot lights, then goes out

I live in Summerland BC, it is currently around freezing, the furnace is in the unheated attic of a one story detached home with a full basement (it supplies heat to only the first floor), and has heat tape on the water drain lines.

I have a 1990 Amana model GSCO75A30A natural gas furnace. It won't start. The exhaust blower starts, the electric pilot starts clicking, and the pilot lights. The gas valve thens gives a click, and the pilot light goes out after being lit for only a few seconds. Then the process starts over, with the clicking of the igniter, then pilot lighting, then going out again...

I have the manual and tried some of their troubleshooting tips. I disconnected the MV wire from the electronic control, that should have let the pilot burn, but not the main burner - same problem as noted above. I also checked that the drain was not blocked, as it has a safety switch on it. I made sure the blower vent was not blocked as this can stop the main burner from operating. I pulled the burner assembly out to make sure the pilot was hitting the flame sensor, that looks lined up and fine.

When the pilot lights for the few seconds it works, the flame looks good, blue and covering the flame sensor completely. I was hoping to avoid a service call on this, but am not sure what else to check! Luckily I have a natural gas space heater in the basement, so I put a fan at the bottom of the stairs to fire some heat to the first floor.

Any help would be greatly appreciated.

Lindsey
 

Last edited by LindseyP; 02-09-07 at 12:58 AM. Reason: added more detail
  #2  
Old 02-09-07, 06:21 AM
HVACGuy's Avatar
Member
Join Date: Jan 2007
Location: Upstate New York
Posts: 134
Likes: 0
Received 0 Likes on 0 Posts
It sounds as if the flame sensor is failing to sense flame, or the ignition control is faulty. Unless you want to replace both, I'd call someone in. If they decide that it's the ignition control, spring for a flame sensor anyway...It's just good prevention.

The flame sensor can be tested by hooking up a multimeter to sense flame current, which usually runs between 0.9 and 2,0 microamps DC.
 
  #3  
Old 02-09-07, 01:28 PM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Thanks, I've put in a service call, after reading what I could find here and other Internet sites, I've run out of ideas! I did try cleaning the flame sensor with a bit of emery paper, but still the same problem - some things are best left to the experts!

Thanks for the advice.
 
  #4  
Old 02-09-07, 04:03 PM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
OK, so the service guy came, then the service guy went - still not working. He was confused because I don't seem to have a flame sensor..... So, what does the Amana (it has a honeywell control mudule) use to sense the flame? Is it built into the igniter? The igniter runs to the control module with only one wire/connection. He wants to replace the control module (doesn't have one on hand, will return with it tomorrow), and sounds like he wants to add a standard flame sensor to it. I don't like the idea because it sounds jury-rigged to me, It has operated the way it is for like 15 years, why change it, especially if it was not designed to run with a standard flame sensor.

Any suggestions or explanations of how Amana detects whether or not there is a flame? You mentioned checking the igniter with a multimeter - can I have more specific detailed instructions on how to do that?

Thanks again.
 
  #5  
Old 02-10-07, 06:48 AM
joeinbarrie's Avatar
Member
Join Date: Feb 2007
Location: Barrie
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
integrated spark/sensor

Sounds like the pilot assembly and ign.control module use the same lead for both

If you put your meter in series with the ground wire (that should be connected to the pilot assembly) the readings posted earlier of .9 to 2 should be present

what model honeywell board? s86??
 
  #6  
Old 02-10-07, 10:06 AM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Yes they use one lead that connects to the top terminal on the control module. I'll try checking the reading on it.

The Honeywell is a S8600M.
 
  #7  
Old 02-10-07, 02:48 PM
joeinbarrie's Avatar
Member
Join Date: Feb 2007
Location: Barrie
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
sorry replacing fan on car today..just read your post.
The pilot assembly should have a wire connected to it under one of the mounting screws and it should come back to the honeywell module. if you disconnect it from the module..set the meter for dc microamps and run it in series(one lead of meter to wire and one lead to module) and start the heat it should give you a reading when pilot is established. The pilot assembly will have a hood on it which carries the current through the flame to ground..try also cleaning the hood.
 
  #8  
Old 02-11-07, 02:24 PM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
That's interesting, but I have only one wire going to the burner area, its the thick one that looks just like a sparkplug wire. I haven't heard of cleaning the hood before, I'll give that a try. Could the current path just go to ground? And the control module senses the current flow through the igniter wire?

If I was to replace the module and igniter wire, any idea how I would find out what the replacements are? I tried the Honeywell site, looks like the 8610U would work, but I could not find anything on the combination igniter/flame sensor.

Thanks for helping me diagnose this!
 
  #9  
Old 02-12-07, 04:06 AM
joeinbarrie's Avatar
Member
Join Date: Feb 2007
Location: Barrie
Posts: 8
Likes: 0
Received 0 Likes on 0 Posts
Sorry it took so long to get back to you. You said that there was only the spark/sensor wire connected. The link below is the installation manual for the S8610U it has a picture of the 8600M with wiring arrangements. There's a burner(GND) terminal on the 8600M which usually goes to the pilot mounting screw. if it's not there try adding it. And the 8610U is a suitable replacement.

Hope this helps. let us know how it works out.

Please exhaust all these suggestions before replacing the control, as new one might do the same.



http://customer.honeywell.com/download/70-6910.pdf
 
  #10  
Old 02-13-07, 11:15 PM
L
Member
Thread Starter
Join Date: Feb 2007
Posts: 6
Likes: 0
Received 0 Likes on 0 Posts
Fixed!

Thanks for the info, I wish it was summer and I had more time to figure this out on my own! I made a few phone calls, and couldn't find anyone who would sell me parts.... they wanted to come and do the install, no surprise. In the end I had a repair company come in and diagnose (they found the control module at fault) and replace it. I was working when they came today, so haven't verified what they replaced it with, but I'm sure it will be a 8610. (Not looking forward to seeing the bill).

Thanks for all the help and input. I will be more prepared next time!

Lindsey
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: