Originally Posted by
Saturatedpsi
I disagree. The indoor TXV is at the outlet of the coil in heat mode, so it would be a liquid restriction. But based on the given information,
..there is no restriction, or very little, since the suction pressure is somewhere near normal for the OD temp.
I agree, but disagree. It the indoor TXV is not bypassing, partially or fully, it will back the liquid refrigerant into the indoor coil. As the liquid stacks in the coil there is less area for the discharge gas to condense. This will cause the head pressure to spike.
It takes less refrigerant in heat mode than cool mode. The excess refrigerant is usually stored in the accumulator in most units, or the properly sized indoor coil in a Lennox. Now the coil essentially smaller and hot gas is being continually add until the HPS opens.
Beware of advice given by some guy on the Internet.