This may belong in wall of shame. Installed a furnace yesterday and got a recall today, it was shutting off on the high limit. Duct work was fine supply and return 100 cfm short both sides not enough to poppin limit in under 2mins, even opening electronic air cleaner and pulling coil panel off.
Should have figured it out here, but was fixated on over sized flue. I do that a lot get something in my head and fixate? not word I'm looking for...
Anyways, after wasting a bunch of time and having to call my boss to help me. He had to call Trane soon as he gave them model/serial they knew what it was.
For some reason they put baffles across the entire heat exchanger!!! Boss noticed that after looking at it but they have DO NOT REMOVE stamped on them.
Had to take pics of it and removing/moving baffles unit tag don't have those my coworker's phone takes much better pics then mine. But thought I'd post this cause it certainly caused me a headache and maybe will save someone else one. Never had this problem before, looking back I should've figured it out quicker but I didin't. Maybe just 100k units I don't know.
And a side note...probably get flamed for this. The limit was 120 thought that was to small didn't have any at shop and parts house only had 160 and up so put that in. Not quite the same as Trane's limits. Should've looked at that Trane's are a little narrower. Didn't touch the edges of the insertion hole but close enough to arc which popped the fuse and caused more frustration.
Hope you had a better day than me:-)
Hate when things like that happen. Simple things always looking right at you
At least you confront the problem directly and wear it. Thats true wisdom.
Did Trane say to remove the baffles?
If more government is the answer, then it's a really stupid question.
What's the full model #? Never seen a limit as low as 120.
Yes, Trane sometimes has baffles. I'd look at gas pressure and check static. Odds are it is airflow.
Yes, Trane did say to remove one of the baffles and move the other to the third chamber. I did check gas pressure.
I'll have to get the model and serial today.
manufacture date 6/20/12
Are you sure about the 120 degree limit? supply air temp should be that high. How would that work?
Originally Posted by brian.cornell
Exactly, I thought the same thing, after opening return and coil and the limit still popped. Looked a little closer at high limit and thought wtf 120 that can't be right so swapped it for a 160 still popped it. Asked my boss about that later and he looked it up on Trane's website said 120 was right. He explained it as the lower temp limit makes the heat exchanger last longer...
I don't know, seems like that is cutting it really close with a temp rise of 30-60 degrees.
I left the 160 in there.
After that limit popped put a temp probe in limit slot and furnace was hittin 132 in about 5 secs before changing baffles.