Trane XE78 - No Gas


Old 10-21-03, 09:08 AM
Visiting Guest
Posts: n/a
Trane XE78 - No Gas

Hey All,
First time poster so please bear with me. I am an electronics technician so I should be able to follow most all of the conversation. I will go right down the list of 7 things you want to see so I dont miss anything:

1) Northern Alabama - current highs of 75, lows of 50
2) All brick, 2100sq ft, 1 level, furnace in attic, condenser outside
3) Trane, XE78, 11 years old, single stage
4) Natural Gas
5&6) N/A
7) Digital Thermostat
8) Over the past 2 years, I have replaced the glow type igniter and burnished the flame sensor. Thats it..(filter was clean)

Current intermittent problem - When the call for heat is requested, I hear a relay click and the igniter glows, but no Gas ignites.. After 8 seconds or so the igniter goes out. The igniter then comes back on and goes out 8 seconds later after no gas ignites. This is repeated 3 times and then the blower comes on blowing cold air through the house. This morning, after 10 minutes, I actually had to lower the thermostat, kick on the A/C, then turn it off to get the blower to stop.

I get the following flashes from the control module:

2 flashes/second continuous - this happened when the Call for Heat was initilized and continued until the blower came on.

2 flashes, then nothing, then 2 flashes, then nothing, repeating - this happened when the blower was on but there was no flame

1 flash/second continuous - Unit was off

A guy came and checked it on Friday, but, of course, the unit would not fail while he was there. It worked through the weekend and then failed last night. I called the heating company back out, but they cant come until tomorrow. I was just wondering if there was anything I could check in the meantime...

thx for the help
Sponsored Links
Old 10-21-03, 09:29 AM
KField's Avatar
Join Date: Dec 2002
Location: Easton, PA
Posts: 3,245
Received 0 Votes on 0 Posts
I would check gas pressure at the outlet of the gas valve on the furnace.
Old 10-21-03, 01:41 PM
Visiting Guest
Posts: n/a
I was hoping for an electronics solution as that is what I specialize in....I guess I will have to have a service guy look at it....



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

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