electric heat pump


  #1  
Old 12-09-00, 01:44 AM
db43
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Unhappy

my heat pump is not defrosting coils completely. when it goes into the defrost mode it will defrost down to about 3-4 inches from bottom of coils. the coils at bottom build up with ice causing the unit to run constantly and the green light for the heat strips come on trying to make up for temp difference in the house. tstat set on 74 and temp in house registering at 68 degrees.tstat was off 2 degrees anyway. once ice has built up unit blows cooler air. when temp outside is above freezing heat pump works fine. i have a 1985 whirlpool.(not real sure about the year).
 
  #2  
Old 12-09-00, 01:59 AM
PDF
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Possible drainage problem

Does your outdoor unit sit close to the ground on a slab?It is possible the drain holes on the bottom are plugged.When this happens,as the coil defrosts,below 32 degrees the water can not drain out.It freezes and begins building up on the lower coils.When you get a day above 32,turn power off and use a garden hose to flush the openings untilthe water runs clear.Before you do this look down to the inside of the unit to see how much debris is inside.Other possibilty is the unit may be short on gas.PDF
 
  #3  
Old 12-09-00, 04:23 AM
fjrachel
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Definitely try PDF's suggestion, you may luck out. You will probably have to call a tech though. The old whirlpool's are critically charge with freon and you may have a small leak. Also they use the old mechanical defrost timer and defrost t'stat and have been known to shorten defrost time when they get older.
 
  #4  
Old 12-19-00, 06:31 PM
db43
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Question heat pump

CLEANED DRAIN HOLES IN BOTTOM OF UNIT. DIDN'T HELP.
CALLED TECH CAME OUT CHECKED GAS OK. HE MOVED CENSORS ON PIPE. HASN'T HELPED. COULD THE DEFROST TIMER AND T'STAT BE BAD? UNIT DOES GOE INTO DEFROST. STILL HAVE THE BUILD UP OF ICE ON COILS AT BOTTOM INSIDE AND OUT. WITH ICE ON THE COILS UNIT IS RUNNING CONSTANTLY IS THIS NORMAL? THANKS FOR YOUR RESPONSE.
 
  #5  
Old 12-19-00, 07:43 PM
fjrachel
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Does not sound normal. If the tech checked your unit correctly he should have found the problem, if there was one. Where you there to observe the technician? How long have you know this particular heat pump system? When the temp goes below freezing is it wet outside?
 
  #6  
Old 12-20-00, 04:35 AM
db43
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Question heat pump

YES I WAS OUTSIDE WITH THE TECH THE WHOLE TIME. HE CHECKED PRESSURE READING AND GAS, HE DID ADD A LITTLE GAS THINKING THAT MIGHT HELP BUT HE SAID GAS REALLY WASNT THAT LOW. EVEN WENT UNDER HOUSE TO THAT UNIT CHECKED. I HAVE KNOWN THIS HEAT PUMP SINCE 1995 AND I DO KNOW IT IS NOT WORKING RIGHT. YES, SOMETIMES IT IS WET OUTSIDE WHEN TEMP GOES BELOW FREEZING. ARE THESE TYPE PROBLEMS HARD TO DETECT?
 
  #7  
Old 12-20-00, 05:32 AM
R-12guy
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That Ice damn at the bottom of your coil is not good...what i think has happened is, the ice has built up, the unit went into Defrost, and the lower tube in the coil has collipased ( pinched itself off). I've seen this a few times, and the unit will show near correct pressures but the coil will have this restriction causing poor preformance...you might have to bite the bullet and best thing to do would be to replace the unit. you will have to remove outside case and make a close inspection of the lower coil to confirm this.
 
  #8  
Old 12-20-00, 04:12 PM
PDF
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R-12 guy

Yes,the pinched tube,good possibilty.Worked on some CARRIER units a bunch of years ago.Because drain holes were plugged the tubing did collapse.Collapsed to the point,and so neat that it looked like it was actually done by a mechanical tool.PDF
 
  #9  
Old 12-20-00, 05:01 PM
fjrachel
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R-12 and PDF have a point. Yet, I do believe you have a freon problem in the system that either has not been addressed or has been missed. You may have a leaky reversing valve, a restricted metering device in the outdoor or indoor unit. Checking freon pressure alone, will not detect these problems, especially in the heating mode. Both freon temperatures, at key points in the system, and freon pressures must be used to make an educated diagnosis.
 
 

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