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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Trane Heat Pump M/N XP19-048-230-05, S/N 5808B28331. Unit runs

Customer Question

Trane Heat Pump M/N XP19-048-230-05, S/N 5808B28331. Unit runs fine, when running. It will run and bring home down to set cooling temp. Unit appears to run for too long a time before cycling off. Then, when it kicks off, it will not restart on it's own. I pulled the condenser panel and found the motherboard red and green LED's flashing on and off together. I cannot find the code to diagnose.
At first, I suspected the contactor, so I manually pressed the contactor bar to activate unit. Compressor kicked on, so I released the contactor, compressor kicked off. I shut off power to unit, waited a bit, then powered back on. After about 3 minutes, unit comes back on, and cools as normal.
Is this a welded contactor or something else?
Submitted: 2 years ago.
Category: HVAC
Expert:  Phil replied 2 years ago.
Hello,Tell me please about how hot outside it is when this happens as a rule... for instance, only on very hot days for example. Tell me how old the outside unit is, and if you have cleaned the condenser coil or not.We can go from there.
Customer: replied 2 years ago.
Typical Florida weather, averaging high 70's at night and getting to approximately 91-95 or so during the day. Unit appears to cool fine, but seems to run constantly during night and early morning. Seems to stop around 11 am or so. This just started about 4 days ago, so no difference in weather pattern other than stated here. We also have rain off and on most days.Unit was new about 8 years ago. I have not cleaned the condenser coils.
Expert:  Phil replied 2 years ago.
Hello again, thanks for the data. So far it sounds like the system may have developed a slow refrigerant leak, and is going off on its low pressure cut out switch occasionally and that you are resetting it by cycling the thermostat on and off. The fact that it seems to be running longer than it should supports that. It is also possible that unit is going off on its high pressure safety cut out switch.... clean the condenser coil and let me know how it goes from there, You can buy 2 or 3 cans of the spray foam cleaner at Home Depot or Lowes or any larger hardware store. can go from there.
Customer: replied 2 years ago.
Okay, will do with the coil cleaning. And with my limited knowledge base on a/c systems, I was thinking refrigerant may be the cause of unit running so much. I will tell you, this is about 3200 heated area home, that had some lack of maintenance over the last recent years during a divorce. I have been here only 2 years, trying to bring it up, but with 20 acres and all, I'm stretched pretty thin, physically and financially. So much for retirement! Anyway, I see all kinds of 'problems' including air leaks from bad door astragals. I have not been in the attic to check insulation or ductwork/leaks. And, there is a second separate a/c for the master bedroom/bath area that is currently out of order. Overall, I know all of these situations are overworking this one unit and wearing it down prematurely. In the winter, it doesn't bring it up much over about 69-70, and just runs and runs and runs.I just thought it fair to give a complete overview on what's going on here. But, aside from this problem that I originally addressed with you, the unit has been cooling and running okay.I won't be able to check/clean the coils until Wednesday, so I'll get back to you with an update once I complete that task.Thanks so much for your input so far.John
Customer: replied 2 years ago.
P.S. I guess it could be a combination of low refrigerant activating the low pressure cut out switch, AND the high pressure cut out switch due to dirty coils/can't breath/overheat?? Or not? Is it typically just one or the other?
Expert:  Phil replied 2 years ago.
Hello again, there are dozens of possibilities, but a refrigerant leak is entirely common, and the condenser after 8 years is in serious need of cleaning. so we will look at those two first. On the 20 acres issue, you could sell all that ahead of our nations next financial fiasco and live in a country at a quarter to an eighth the cost, and plenty of free time. I am on Lago Atitlan right now. very nice. heat or AC required its at 5,000 ft in the tropics, about 65 to 75F 98% of the time.Home repairs are $1 an hour.