Hey Folks,
I have a Trane 1200XL heat pump and every once in a while when the unit cycles on, the condenser fan and compressor won't go on but I hear the unit humming. After 30 to 90 seconds later, the condenser fan and compressor kick on and everything is OK. I tried replacing the contact switch in the condenser unit thinking that the contacts may be burnt out but that didn't work. The circuit board in the condenser unit outside has an LEN that flasshes once every second but that is all I see. Any ideas as to why the unit will delay start-up? Again, it will happen maybe one out of 20 times that it cycles. Thanks for the time. It is truly appreciated!! Chris

The delay could be built into the thermostat you have or the outside unit. Many times the factory will have a built in delay or it was added during the install. Let it run as long as everything else is working OK.

Thanks for the quick reply. The one thinbg I forgot to mention is that the furnace blower comes on and it blows cold air into the house until the condenser unit kicks in that 30 to 90 seconds later. So, even though things work themselves out in that 30 to 90 seconds, there is cold air blowing and the wife is not happy. Any ideas? Thanks!

Then it is time to call a professional and see what is causing the problem. There are many different items it could be and I am sure you want to keep her happy. The more you dilly and dally around the more unhappy she is going to get. I do not have a reset or a push button cure for this problem. The controls and electronics will have to be looked into and that is a nice unit you have so I would not want any damage to happen to it while we try and find the problem.

Also according to your post this is a intermittent problem and I suggest you get a person who has experience with that unit or they may never find the problem since it may not act up when they are there. If your unit does it there is a good possibility other units like yours have done it also. That is why you need a experienced on site service professional that knows that unit. If you get lucky with the right person they might be able to go right to the problem.

Good advice! Thanks.