I don't know, jrbenny seems to think the same thing and he would know better than I would. I haven't touched a residential unit in 8 years and the last residential heat pump I installed shut down the outdoor unit below 20º. The residential equipemnt has canged so much sense I've worked on it, I don't have enough knowledge on it to make anymore comments on the subject.
I must have missed something!
Jumpering W2 and E together only helps you when you tie all heat strips in together. Some air handlers like Rheem and Ruud actually have the purple wire to energize a set of heat strips. If the heaters are big enough then they also have white black stripe and white blue stripe. If you only make w2 the blue and black striped white wires then you will have all the heat strips on (the purple ties in with one of the striped wires on the sequencer.) If you go to Emergency... then only one sequencer gets energized and typically you loose half your electric heat. Thats why we almost always tie all heaters in to W2 and E. E doesnt kill the heatpump. Its just that E doesnt have a y signal out to start the heat pump.
Why would you not use the heat pump for as much of the efficient heat as you can get instead of using the costly electric heat? Add the 2 together when its really cold (like its designed) and you will stay toasty warm.
if you have a problem with your heat pump.... (call your contractor) like a bad compressor.... no refrigerant etc etc... then by all means bypass the heat pump and allow the Tstat to control the electric heat like it should. If you dont and run in normal with a bad heat pump you will typically only get to withing 2 degrees of the thermostat setpoint and the elctric heat will cut off and the ahu will blow room air around.
We only install lockouts on the heat pumps if the are part of a dual fuel package.
Silent Service........ Death From Below!
Somewhere in Kansas, a town found a village idiot!