Trane Question

May 24, 2008 11 Replies

Hi all-



I have a question concerning my old (1993)Trane 1400XL. As it's gotten hotter out it seems to be running longer, and not blowing quite as cool as I remember it being this time last year. It normally has a duct temp of 55-58, but it will now rise up to 61-63 during the peak of the day (about 95 outside). Being I was in the trade eons ago,and still having some of my equipment, I decided to hook my gauges to it and see where it was at. The high side was around 225, the low around 80, and the superheat fell right in the middle of the chart for the unit (10 degrees). Just as I went to remove the gauges I heard a buzzing that sounded like a relay. The moment the buzzing started the superheat reading fell to within 2 degrees which is obviously outside the acceptable range. After a few minutes the buzzing stops and the superheat reading goes back to normal. It seems to repeat this cycle every 5-10 min day or night. My question is- is this normal for this unit or may I have a problem?



PS- Before you guys hammer me for being a DIY'er, I have no intentions of doing anything further myself. If this operation is not normal I will be calling Trane out next week.



TIA,



Jon


Its probably undercharged.... look for 10 - 14 degrees SC... if thats the case, then you have a leak somewhere.

The one time I worked on a Trane heat pump, it looked clean as can be. Just for good measure, I gave it some alki foam on the condensor coils. Wait a while, rinse it off. Repeat to see if anything visible happened. I didn't get the good white foam I usually get with window AC. Fired up the unit, and the amperage had dropped about an amp.

This was about a year ago, don't have all the numbers, pressures, and so on. But, cleaning the condensor never hurts.

Buzzing. Well, could be main contactor. Makes me wonder if the reversing valve is operating, to throw the unit into defrost? Just don't know, not there to see.

Rising indoor temps while under load sounds like either low charge, or a dirty coil. Indoors or out. More likely outdoors.

Please let us know how things work out.

By chance, did the 'buzzing' you're hearing come from the compressor? And is the compressor a recip or a scroll? With a higher suction reading, there may be a relief valve in the compressor open or slightly open causing a bypass condition and resulting in a drop in performance [less cfm pumping.]

Stormy has only ever worked on ONE TRANE HEAT PUMP??? Oh, that's right, I forgot he was a lock picker.

Hvacmam

I live in New York. We don't have many heat pumps, here.

He didn't actually *work* on the unit, his boss did, he was just the gopher.

Actually, I was at a different location than the boss, and I was the only tech on the job.

So, it was a PM job...

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