Rheem heat pump defrost cycle question

[showalter.bruce.a]

My question is about the sequence of operation during the defrost cycle.

I am an electronics technician with an engineering background.

The air handler is an RH1T4821STANJA, outdoor cube is an RP1548AJ1NA, therm ostat is a Honeywell TH8000 series.

Installed April of 2015, AC works fine, cycles normally.

I am OCD about observing home appliances and equipment, and do [most of] my own repairs, which drives my wife crazy, but I digress.

I have observed at least a half dozen defrost cycles, if I am there to do s o, and I notice first of all that the RV is noisy, making a large "grunt" w hen switching. The outdoor fan also stops, which I know is normal. What I am concerned about is that the compressor also stops (nothing running outs ide), at which time I can hear the refrigerant flowing until pressure is eq ualized, then the compressor starts again in defrost (AC) mode. It does ru n until ice is melted (usually around 3 min.), then stops again. All this time, the air handler is running normally, and aux-heat is working to compe nsate vent temp. Then after not quite a minute, the compressor and outdoor fan come back on, and we're back to normal operation.

I previously had a Bryant heat pump, and during defrost, the compressor nev er cycled off during defrost operation like this one does.

My question is whether this is normal, or if this is indicative of an impro per charge (call service) or a wiring issue (which I can fix)?

[dieselolds]

rmostat is a Honeywell TH8000 series.

my own repairs, which drives my wife crazy, but I digress.

so, and I notice first of all that the RV is noisy, making a large "grunt" when switching. The outdoor fan also stops, which I know is normal. What I am concerned about is that the compressor also stops (nothing running ou tside), at which time I can hear the refrigerant flowing until pressure is equalized, then the compressor starts again in defrost (AC) mode. It does run until ice is melted (usually around 3 min.), then stops again. All thi s time, the air handler is running normally, and aux-heat is working to com pensate vent temp. Then after not quite a minute, the compressor and outdo or fan come back on, and we're back to normal operation.

ever cycled off during defrost operation like this one does.

roper charge (call service) or a wiring issue (which I can fix)?

I am not sure about Rheem/Ruud but Trane do that. I think it is mainly for noise reduction. some of those scrolls can make a godawful racket when the valve switches over.

[Bruce Showalter]

hermostat is a Honeywell TH8000 series.

] my own repairs, which drives my wife crazy, but I digress.

do so, and I notice first of all that the RV is noisy, making a large "grun t" when switching. The outdoor fan also stops, which I know is normal. Wh at I am concerned about is that the compressor also stops (nothing running outside), at which time I can hear the refrigerant flowing until pressure i s equalized, then the compressor starts again in defrost (AC) mode. It doe s run until ice is melted (usually around 3 min.), then stops again. All t his time, the air handler is running normally, and aux-heat is working to c ompensate vent temp. Then after not quite a minute, the compressor and out door fan come back on, and we're back to normal operation.

never cycled off during defrost operation like this one does.

mproper charge (call service) or a wiring issue (which I can fix)?

r noise reduction. some of those scrolls can make a godawful racket when th e valve switches over.

Thank you for the reply. The "groan" noise I hear when the RV switches I c an live with, but it still kind of bothers me that the compressor cycles of f, instead of just reversing flow like the old Bryant did. Old school thou ght still has me believing that short-cycling a compressor is bad. I guess at least it does wait for the pressure to equalize, so it's not like it is starting against pressure.