I have a PTC153 A50AC that the heat will not kick in

no info generic answer check and test thermostat and wiring circuit fan & heat should not be coming on when in a/c mode

The emergency heat likely randomly kicks on when your heat pump enters defrost mode.

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How do you get it to kick in ?.Fid you spin it by hand ,if that's what you did and fan runs then you have a bad capicator. If fan runs fine in cooling and not in heat then you have a bad board

check thermostat setting. make sure unit is on! when u say "air will not kick on"? are you saying the heated air is not blowing out? if no hot air, there is no heat to blow out! fix furnace!

have controller checked

have the controller checked

Heat pumps defrost which is the AC mode, if the heat strip isnt working during a defrost, the air will be cold, A heat pump only feels warm if the heat strips are on too! the refrigeration cycles heat output is much less sensible to our 98F skin. heat pumps that satisfy a room setpoint are working at least, all heat pumps feel drafty to most.

Try replacing the barrery.

these are heat cycles,
the click you are hearing is the thermostat turning the element on or off, most dryers try to acheive a temp of 160 - 180 degrees, when reached the element shuts off for a bit to cool down and not scorch your clothes
you do not have to worry about this