Forums | Home Repair | Home Improvement | Painting | Interior Decorating | Remodeling | Landscaping


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 10-28-2012, 03:47 AM   #1
Newbie
 
Join Date: Oct 2012
Posts: 2
Share |
Default

Warm air Furnace


With new gas valve and thermocouple the furnace maintains pilot and when thermostat calls for heat furnace goes to main flame and keeps going for hours but when it has reached temperature main flam closes down and extinguishes pilot as well. Any ideas what is wrong?
sidb is offline   Reply With Quote
Old 10-28-2012, 05:37 AM   #2
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 23,477
Default

Warm air Furnace


Moved to HVAC forum.
beenthere is online now   Reply With Quote
Old 10-28-2012, 06:14 AM   #3
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Default

Warm air Furnace


Could be a crack in the heat exchanger opening up. Anytime a problem could be a heat exchanger breach it's time to put the tools down and call a pro.
Marty S. is offline   Reply With Quote
Old 10-28-2012, 06:45 AM   #4
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,574
Default

Warm air Furnace


sitting in front of the furnace looking into the main burner section restart it ...with the main burner lighting up then note the supply fan coming on.if you see the slightest wave in the burner flames the heat exchangers is cracked...the pressure of that fan is leaking into the burner section and in turn the fle gases leak ino the supply air
biggles is offline   Reply With Quote
Old 10-28-2012, 07:52 AM   #5
Member
 
Join Date: Oct 2011
Location: pa
Posts: 4,002
Default

Warm air Furnace


after checking what the others said....if valve is new was manifold pressure set right. could be comming on hard and going off hard blowing pilot out.. is pilot strong enough...ben sr
ben's plumbing is offline   Reply With Quote
Old 10-28-2012, 12:47 PM   #6
how
Member
 
Join Date: Feb 2011
Location: Vancouver BC
Posts: 1,473
Default

Warm air Furnace


Have someone turn the furnace on for 10 minutes and then off while you are watching the pilot flame through the entire heating cycle..

As others have said..does the pilot flame differ between when the blower is working and not.

Does the pilot flame lift off the thermocouple from the exchanger heat drawing air with a natural draft furnace when the main burners turn off.
(or at anytime through the heating cycle.)

Is there a small explosive popping when the main gas goes off that is extingushing the pilot.

Is the thermocouple presently fully enveloped by the pilot flame.

Send a photo of the new gas valve directed at the side that the pilot thermocouple attaches to. Some have eco connections that allow the metering of the thermocouple output while its still attached to the gas valve. This would tell you what the real pilot output is and whether the new pilot solinoid is actually strong enough.

Report back what you see as they all have different solutions.
how is offline   Reply With Quote
The Following User Says Thank You to how For This Useful Post:
ben's plumbing (10-28-2012)
Old 10-29-2012, 08:41 AM   #7
Newbie
 
Join Date: Oct 2012
Posts: 2
Default

Warm air Furnace


Problem has changed, now main flame won't ignite, pilot still going but blew 500mlamp fuse, replaced but still won't go.
sidb 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
Moving furnace & redoing ducting cbrc5eric HVAC 0 02-09-2012 08:13 AM
Propane Furnace - Diminishing Gas Supply After Ignition edro HVAC 9 01-13-2012 04:24 PM
Furnace Turns on when it gets too warm wmsward HVAC 7 06-08-2009 11:22 PM
Problems with new furnace..Overheating, having to reset. Furnace too big? Tommy2 HVAC 41 12-01-2008 01:55 PM




Top of Page | View New Posts

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