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 12-23-2009, 02:00 PM   #1
Newbie
 
Join Date: Dec 2009
Posts: 4
Share |
Question

Bryant Gas Furnace - blower sarts and stops


We have a Bryant gas furnace (model 394GAD I think). When the thermostat calls for heat, the burners start up, then after 45 seconds or so, the main blower. After about 3 minute, the blower stops, but the burners remain on. Then 30 seconds or so later, the blower starts up again. Three minutes or so later, blower stops, burners continue, then after 30 seconds, blower starts up again. Keeps repeating this cycle until temperature on thermostat reached - then whole furnace shuts off (blower and burners). Any ideas?

montepix is offline   Reply With Quote
Old 12-23-2009, 02:08 PM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 24,741
Default

Bryant Gas Furnace - blower sarts and stops


Blower could be moving too much air.
Or burners could be underfired.

beenthere is offline   Reply With Quote
Old 12-23-2009, 02:15 PM   #3
Newbie
 
Join Date: Dec 2009
Posts: 4
Default

Bryant Gas Furnace - blower sarts and stops


Furnace has been in place for 18 years - worked fine until about 2 months ago. Changed out thermostat to see if that helped - it didn't. There doesn't seem to be any thermal limit switch that determines if main burners are hot enough before starting blower - just a time delay circuit - although, I agree, the system is acting as if there is one.
montepix is offline   Reply With Quote
Old 12-23-2009, 03:04 PM   #4
MXer
 
3 legged dog's Avatar
 
Join Date: Dec 2009
Location: South West Coast
Posts: 128
Default

Bryant Gas Furnace - blower sarts and stops


Post a picture of the time delay if you can.
3 legged dog is offline   Reply With Quote
Old 12-24-2009, 10:29 AM   #5
Newbie
 
Join Date: Dec 2009
Posts: 4
Default

Bryant Gas Furnace - blower sarts and stops


Timer circuit is located on the main control board. It is apparently solid state (according to the circuit diagram). I have ordered a replacement board and will try that. However, I was wondering if there really is an "air low temperature" limit in this furnace or not.
montepix is offline   Reply With Quote
Old 12-24-2009, 11:10 AM   #6
HVAC Tech/ Browns Fan
 
Join Date: Dec 2009
Location: Dayton, ohio
Posts: 541
Default

Bryant Gas Furnace - blower sarts and stops


U can hear if the relay is cutting in or out. You may need to check and see if one of the wires is coming off the blower motor
Tator1076 is offline   Reply With Quote
Old 12-24-2009, 12:22 PM   #7
Newbie
 
Join Date: Dec 2009
Posts: 4
Default

Bryant Gas Furnace - blower sarts and stops


Yes, the relay is opening and closing.
montepix is offline   Reply With Quote
Old 12-24-2009, 04:11 PM   #8
HVAC Tech/ Browns Fan
 
Join Date: Dec 2009
Location: Dayton, ohio
Posts: 541
Default

Bryant Gas Furnace - blower sarts and stops


Its maybe lose wire or worst bad motor. You need to check to see if getting the right volts to motor then ohm the motor out.

Tator1076 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





Top of Page | View New Posts

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