Heat Pumps and Electric Heating - Defrost delay

I would like to know if the period of time can be delayed when my Heat Pump switches over to defrost....as you can read from my other posts I am having periodic issues with the compressor struggling to run when the pump switches over for defrost....not all the time just sometimes...does the compressor have to immediatly switch over to defrost or can it wait 2-5 mins...I have a 2003 Armstrong Air(Allied) Heat Pump model # SHP10E24-A and the last time the Tech came he installed on of those "Talking" t-stats....also what is the best location for a Heat Pump....mine was here when I bought the house..its on the "North" side of my House..right out in the open....I`m on the north shore of Lake Ontario an hour and a half east of Toronto. any input is appreciated.:coffee:

I ran into a similar sounding situation recently but it was a Commercial lennox heat pump. There was a bad check valve in the system, you might have your tech check on that. I am not sure how Armstrong sets up there heat pump piping. It does sound like something in the system is causing excessive head pressure. It is kinda hard for a tech to find the problem if it is intermittent so you may have to pay for his time for several hours until the unit malfunctions and he can get the readings needed for a proper diagnosis. Note: the unit that we were working with was also intermittent so we installed electronic data gathering devices that recorded the pressures/amp draws over a 2 day period but I doubt that ANY residential type techs would even have access to that type of equipment. Most good techs will figure it out without all the fancy gadgets anyway. Good Luck