[mrdan3000]

Problem: Trane XB LED blinks 5 times and blower won't stop running, but no heat.

Any ideas what the solution is? I am thinking some kind of fan control board. I can shut off power to the whole unit, but when I power back on I get the same problem. Blower runs with no heat. The thermostat can be set to "heat" or "off" but the blower still runs. The blower is in "auto." I tried resetting the ICM, but it did not fix it. This unit is only a few years old - maybe 2006. Please help! It's cold outside!

[hvac1000]

Look on the back side of the blower access door and post the answer to your 5 blink code. Then post the complete EXACT model number of your unit.

[mrdan3000]

Model: tuc1b060a9361ab

Error: flame sensed when no flame should be present

There is definitely no flame present. I reset the unit and the blower immediately comes on even though I turn it off at the thermostat (blower is set to auto). I inspected the flame sensor but it visually looks OK.

[mygirlsdad77]

OK, I've seen this code written on many diagnostic charts, but have never actually seen the coded blinked out on the control board. Im hoping hvac1000 can shed a little lite on this situation, as I've wondered what I would do if I came across it. The way I see it, this code would come in when the gas valve stuck open. But more likely your board has malfunctioned. I was thinking you had a tripped high limit, or rollout, but the flame sensed when no flame should be present is throwing me off. Can you clear this up for us hvac1000.

[hvac1000]

As per the factory (If all other components check out as OK then replace the circuit board).

Both Trane and there sister American Standard/others have this programed into there boards. It is somewhat of a catch all code. If something fails and the board cannot figure it out it dumps it on 5.

Now remember the magic words (If all other components check out). Make sure that all limits are reset or PROVEN good along with all other components. Check for the famous polarity problem also. In other words pull all the tricks out of the bag then if all is OK replace the circuit board.

[mygirlsdad77]

Hear you loud and clear. Thanks again. Never have been a big fan of replacing the board unless I can prove (beyond a reasonable doubt) that the board is the culprit. Can't always rely on the diagnostic code, that I've learned the hard way.
I really appreciate your feedback hvac1000.

PS. Nothing tickles me more than going on a furnace call, the homeowner tells me that he just replaced the board, but furnace still doenst work. Then I clean a flame senser, or clear a blockage in a vent,or condensate drain line, or etc etc etc. Always nice to see the look on the homeowners face after such an easy fix(for someone that nows what to look for and how to test the system correctly) Then they say, so I just waisted 100 bucks(or much more) on a board. And all I can say is, yep, but at least you have a spare board if the need ever arises, oh you threw it away and the garbage man came this morning, oh, I'm really sorry to hear that. Here's my card, I'm betting it will save you money in the long run. Have a nice day.

[hvac1000]

That is a good way to do the biz. My guys would get fired if they ever berated a customer in person and I found out about it. Now in the shop the next morning there were always good customer tails from the day before and some were so funny they bordered on the insane.

I can never blame a customer for trying to save some $$$ but most of the time they end up spending more than if they would just allow the pro to fix it to start with. It is like the thermostat tail which is true. As in all areas we have subdivisions where all houses are about the same and all furnaces etc are the same. One year a service Tec from my office had to install a new thermostat for a customer in one of the subdivisions. Now we all know that a thermostat that has been working all along is usually the last item you would ever replace since the dag gone thing last forever but this one needed to be replaced. Over the winter we had quite a few calls at different homes in the same subdivision and when our service Tec got there the first thing they were told is that the thermostat was replaced by the husband but the furnace still would not work. This led to the famous question of that year (Why did you replace the thermostat Mam. Our guys were instructed to use yes Mam and no Mam to be polite) and the answer was always Susie, Mary, and all the rest of the neighbors replace there thermostat whenever the furnace breaks since that is how Alice Johnson's husband fixed theirs. Rumors like this abound on the net and also in person to person communication and as we see every day all it does is cost the customer more money in the long run. I miss those stories at 6:30 AM contractor time every work day.

[mrdan3000]

I replaced the board. Problem solved! Thanks for your advice.

[hvac1000]

Glad you got it going.