Ask Experts Questions for FREE Help !
Ask
    ObscureUser's Avatar
    ObscureUser Posts: 1, Reputation: 1
    New Member
    		  
    #1

    Aug 2, 2007, 09:43 AM
    AC cycles on/purge repeatedly for 1/2 an hour
    Just replaced old condenser (unit kept drawing too much power and tripping breaker, continuously getting worse) with Lennox AC13 and matching line set and evaporator coil.

    New AC unit cooling house and breaker does not trip, but one problem still exists with the new unit that we had with the old unit - sometimes the AC gets into a pattern where the condenser and fan are on for 20-60 seconds, the condenser and fan turn off then the fan immediately turns on again for 20-60 seconds (purge cycle), then they both come on again and the cycle repeats. This pattern can last for more than 30 minutes.

    The house has 3 zones, each with a thermostat. This pattern usually happens when one zone is close to or at the set temperature, but the AC is still commanded to run (based on the snowflake symbol on the thermostat). The other zones are usually not active when the pattern occurs.

    Any ideas of what may be wrong? Thanks in advance.
    acetc's Avatar
    acetc Posts: 1,004, Reputation: 79
    Ultra Member
    		  
    #2

    Aug 2, 2007, 03:22 PM
    If you have a low pressure control in the outdoor unit it may be kicking off on this switch , this can happen due to low on refrigerant . Lack of air flow will cause the system to run at a lower pressure. Need to watch it with a set of guages on the system to varify.
    joeygeorge's Avatar
    joeygeorge Posts: 2, Reputation: 1
    New Member
    		  
    #3

    Oct 7, 2012, 11:46 AM
    It is a low ambient out door temp switch. The fan will not com on until the head pressure in the condenser hits a certain level and then turns the fan off when the pressure is too low etc. when it cycles on and off again, block condenser airflow with cardboard and see if the fan stays on continuously. Only do this when the outdoor temp is below 70 degrees or you have gauges on to monitor the head pressure.
    joeygeorge's Avatar
    joeygeorge Posts: 2, Reputation: 1
    New Member
    		  
    #4

    Oct 7, 2012, 11:48 AM
    Quote Originally Posted by joeygeorge View Post
    it is a low ambient out door temp switch. the fan will not com on until the head pressure in the condenser hits a certain level and then turns the fan off when the pressure is too low etc. when it cycles on and off again, block condenser airflow with cardboard and see if the fan stays on continuously. only do this when the outdoor temp is below 70 degrees or you have gauges on to monitor the head pressure.
    Look for a green module with two blue wires coming out of it on the smaller liquid line. This is the low ambient kit installed to let customers run ac when it is too cool outside.
Not your question? Ask your question View similar questions
 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Purge control Valve [ 1 Answers ]

I have a 1998 nissan Altima and I'm trying to located where it is because I went to a mechanic yesterday and He didn't know where it was. I'm trying to do it myself. If anybody knows I need some help thanks

Faulty evep purge [ 1 Answers ]

I'm aware of some issues with a faulty evap purge solenoid but my question is to what extent would you get poor idling and surging because of it? I've read about it but not everything is as clear as books try to sound

Washer shuts off repeatedly. [ 3 Answers ]

I have a washer and dryer set we bought in 2003, when we moved into our new home. Everything was fine with the washer in the start, but now, when I put a load of laundry in, the washer quits, at least 3 times, always in the middle of the rinse cycle. I have to go and turn the knob slightly to get...

Is it right to kill someone if they are repeatedly abusing you? [ 10 Answers ]

What do you think? Should it be legal or illegal? When I say someone, I mean for example, boyfriend, girlfriend, husband, wife, close famil members.

Thermostat Cycles Per Hour [ 3 Answers ]

I have a multi-zone (5) HWBB heating system attached to programmable thermostats. The thermostat has a "cycles per hour" setting. What does this do, and what should I set it to? It's currently set to "3" on all thermostats.

View more questions Search