Trane XL90 Highlimit Switch Open - HVAC - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 01-18-2013, 07:21 AM   #1
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


Two Trane 90XL installed 2000 run off one thermostat. One runs great now. Second furnace blows cold air and burners have no flame.

First service tech said problem was drain tube loose and pressure set too high.
Adjusted pressure and cleaned drain tube and reservoir. Same thing happened again in 3 days.

Second tech says that the main board is shot because the 4 light pulses indicate the high limit switch is malfunctioning. He jumped the high limit and the furnace started normally then quit.

He says the board is shot and needs replaced.

Can any one confirm his diagnosis?

Advertisement

burger19 is offline   Reply With Quote
Old 01-18-2013, 07:32 AM   #2
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,365
Rewards Points: 1,094
Blog Entries: 1
Default

Trane XL90 Highlimit Switch Open


No, board is not shot. You have an airflow issue. (blocked supply vents, blocked returns, plugged filter, plugged evap orator coil, plugged secondary heat exchanger coil, weak blower motor, inoperative blower motor, or weak blower motor capacitor) First thing to do is identify why the main limit is tripping, then if the limit is sticking closed you should replace the limit.

Advertisement

__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 01-18-2013, 11:20 AM   #3
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


Thanks for your response.

I took off the cover to expose burners but did not pull them and to access the high limit switch in the ex changer chamber.

The wire were in a connector. I put a small wire into the connector and turned the furnace back on. There was a zap noise and I had to reset the breaker.

After resetting the breaker the furnace came back on and the error code blinked 9 times. I checked the on the door of the furnace 9 blinks check ignition.

I checked several times and confirmed there are now 9 blinks instead of the 4 blinks.

The furnace still blows cold air. I checked and there are blocked supply or returns.

What do you think?
burger19 is offline   Reply With Quote
Old 01-18-2013, 12:29 PM   #4
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,365
Rewards Points: 1,094
Blog Entries: 1
Default

Trane XL90 Highlimit Switch Open


You have likely ruined your control board by shorting it out
__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 01-19-2013, 07:38 PM   #5
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


The furnace i now running I must have some how reset the high liit switch. I laso mad e sure there was nothing blocking supply and returns.

However, the flame is not bue like the first furnace it is amber yellow.

What is missing, thanks.
burger19 is offline   Reply With Quote
Old 01-19-2013, 09:05 PM   #6
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,436
Rewards Points: 4,518
Default

Trane XL90 Highlimit Switch Open


Is the inducer running.
beenthere is online now   Reply With Quote
Old 01-19-2013, 09:18 PM   #7
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


The inducer was running previously .When I returned to the property I really only felt the heat and looked in the heat exchanger through the see through window to see the amber fame. I initially thought the board was blown so seeing it working was a relief.

Things seem to be normal but there was not a strong air low at the affected vents.

Is there a serious problem if the inducer is not running?

Will the furnace be destroyed?

Thanks
burger19 is offline   Reply With Quote
Old 01-19-2013, 09:27 PM   #8
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,436
Rewards Points: 4,518
Default

Trane XL90 Highlimit Switch Open


Shouldn't even be able to light the gas without the inducer running. but you shorted something out. So no telling what may happen. It need attention.
beenthere is online now   Reply With Quote
Old 01-19-2013, 09:31 PM   #9
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


How serious is this? Can it wait until tomorrow? What do you suggest?
burger19 is offline   Reply With Quote
Old 01-19-2013, 09:33 PM   #10
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,436
Rewards Points: 4,518
Default

Trane XL90 Highlimit Switch Open


I'd shut it off. You could be sooting up he secondary heat exchange. No telling if the safeties work now.
beenthere is online now   Reply With Quote
The Following User Says Thank You to beenthere For This Useful Post:
burger19 (01-19-2013)
Old 01-19-2013, 11:12 PM   #11
Newbie
 
Join Date: Jan 2013
Posts: 6
Rewards Points: 10
Default

Trane XL90 Highlimit Switch Open


Okay I shut it down. I'll get serviceman tomorrow or Monday. Other furnace running well.

Thanks for the info. safety First Always.
burger19 is offline   Reply With Quote
Old 01-19-2013, 11:28 PM   #12
An old Tradesmen
 
Join Date: Oct 2008
Location: PA
Posts: 26,436
Rewards Points: 4,518
Default

Trane XL90 Highlimit Switch Open


Good decision.

Advertisement

beenthere is online now   Reply With Quote
Reply


Thread Tools
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
Diagram for 3 way ceiling fan light switch Aurora65 Electrical 22 11-27-2012 10:11 AM
3 way switch layout has me confused crescere Electrical 5 09-08-2012 11:26 AM
safety overflow switch trane xl14i jeffrey sehl HVAC 2 08-10-2012 11:15 AM
can switch work for two different outlets? jlmran Electrical 8 02-10-2011 01:31 PM
Basic Switch wiring question; Dimmer to Toggle switch (Pictures included) inspectator Electrical 8 08-07-2007 02:19 AM




Top of Page | View New Posts