Trane- very little heat


  #1  
Old 12-22-03, 02:44 PM
davidvn
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Trane- very little heat

Hello all:

I am newbie to this forum and here is my question regarding to Trane central heat pump unit.
Last couple day when weather is cold 20F degree and turn on heater and very little heat came out of the vent.
1. It is Trane central H/P was installed in 9/1987 new house
2. New air filter
3. Replaced fan motor (OD unit) start up cap.
4. System have not recharge freon yet for 16 years of services.

The indoor and outdoor motor working great. However, I noticed the compressor kind of humming, whinning noise. Like I mentioned before there was very little heat sense at the outlet vent.
Could I possibly have low freon?
Have service call for the tech to come out and recharge system tommorrow. Any help is appreciated and thanks for letting me sharing.
 
  #2  
Old 12-22-03, 04:07 PM
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how hot is the big freon line at the outdoor unit? 115 to 135 degrees over outdoor temp is good. your strips may not be wired correctly.
 
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Old 12-22-03, 08:04 PM
davidvn
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Hello
Hvac4u, thanks you for a quick and expert advice. I touch and felt hot on the big copper line. I do not have any equipment to measured this temp, and for the strips, not sure what is it, but I don't thinks it has been removed for any reason. I am the orginal owner and have not removed or attemped to fix it yet. Can you please clarify what is exactly the strip and its functionality?
Please advice.
Regards
David
 
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Old 12-23-03, 03:24 PM
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strips are the electric heaters in the air handler that provide supplemental heat and come on during defrost. put it in emergency heat, do you get any heat?
 
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Old 12-28-03, 05:13 PM
davidvn
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Hello all:

hvac4u, thanks for the explanation of the heater stripe. The service tech came out and recharged system with 2 lbs of R22.
Check entire unit and measure the outside line temperature was 115 F, then measured temp. in handler unit was also indicated 114F. However, I need to replace compressor coil contactor 24 VAC was locked up.
Questions: I noticed when tech recharge freon with pressure gauge.
1. What is the normal operating pressure on the low side?
2. High side?
3. How do you know when units have enough freon? not overcharge? Trane spec. called out 5 lbs of R22
4. What is the tip of looking for when replaced 24VAC coil contactor? I maked a freehand sketch of the contactor before attempted to change it out.
BTW, heating strip still in good working condition.
Thanks
David
 
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Old 12-29-03, 08:16 AM
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Did he find a leak?

Just take the old contactor with you. They are pretty standard and an easy replace.
 
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Old 12-29-03, 05:44 PM
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gotta find that leak, or he will be back out. did he look for it? how old is that unit? did he access the contactor from the top or side? if side, the contactor should be no problem, if top, those contactors wire up differently, jumper wire may throw you off. if it cooled ok, and you have never put freon in it, leak may be on high side, indoor coil/piston, service valve, etc.
 
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Old 01-06-04, 02:04 PM
davidvn
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Hello all:

The unit is 16 years old Trane mod# BWD730A100B1. Fortunately there was no freon leaked and last year 8/02, I replaced a fan motor run capacitor rated 5uf, 370VAC and the outdoor unit worked beautiful until later this year. Hvac4u, The contactor is located at the top side position. Bought a 2 poles 24VAC contactor and you are right, the wires connection is throwing me off too. Question?
1. It is possible to obtained an OEM contactor, I think p/n is WW24X138 according to the schematic diagram?
2. If not, an universal contactor will work right?
3. On the oem contactor relay there was a jumper wire(brown/red marker) across one of the contact point.
4. However, the universal one have two contact point.
Please advice
David
 
  #9  
Old 01-06-04, 06:59 PM
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Can you imagine...

What would you think of a plumber if when you complained of a loss of water pressure because of a leaking pipe...he turned up the pressure??? Thats eccentially what he did. The only exception is if is a real slow leaker. With R22, a cheap gas, it's feasible in some instances, but a leak check with the electronic detector may find it without a hole lot of trouble....lets say 20 minutes.....and date the unit with a sharpie of the amount added.
This way if a different tech comes out, he'll know to look deeper.
Teenagers and huffing has become a problem now days too!
as for the contactor, like mentioned ....bring it with you...It most likely has a 24V coil. Use the same jumper as on the old one...


 
  #10  
Old 01-13-04, 05:52 AM
davidvn
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Hello everyone:

As for the relay contactor problem is solved. I was fortunate to located an exact replacement part for Trane H/P system. Wires in is very simple and straight forward.
Just for other information, the replacement P/N is 3ARR8 MARS is manufactured by GE. Very high quality built made in the US .

Again, thank you all for great advice
Regards
David
 
  #11  
Old 01-13-04, 03:15 PM
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glad to hear problem solved. that is a unit that you should start consider replacing before it forces you to, especially if it was low on refrigerant, this causes a lot of wear on the compressor
 
 

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