Heat Pumps and Electric Heating - Some Questions About A New York System

A couple of questions about my 7 month old York YZB02411 with the MV12BN21 air handler, MC30B3XH1 coil and Braeburn 5200 thermostat. I would like a second opinion vs my installer. 1. First, for this configuration, would you please indicate all of the correct low voltage wiring connections between all units. 2. Secondly, what does it mean when the large pipe from condenser entering the air handler is too hot to touch but the air flowing from the registers is not that warm. 3. Next, I am not sure my electric heat is coming on during the defrost cycle, ie, high fan, compressor running (cool?) large pipe is cold, condenser fan off, cold air from register. 4. And finally, at 10 degrees F outside temperature, is it normal for the room temperature to be 2 degrees below tstat setting and then cycle up when the aux heat kicks in and then start the cycle over again? Thanks, Mike

Ok, This how I see it should be wired up. FIY, I had a hard time finding the wire diagram for the unit outside. So, let me know if I am missing something or you don't have it.

T-stat-----AH-----HP
R-----------R------R
Y1---------Y1-----Y1
Y2-----Y2out
W2----------------W
E-----------W1----W1out
W2----W2out
Y2-----Y2out
G-----------G
O-----------O-------O
L-----------X/L------X/L
C----------Com------C


As for the t-stat settings.

1- up to you.
2-recON
3-22HP
4- skips
5-2HE
6- auHE
7- fan0
8- sspON
9- comON
10- AcON
11- F or C?

The heating coil should come on when the outdoor unit is in defrost.

Anything else, please let me know.

Jay,
Thanks for the response. You had listed W2 twice? Currently, my hookup is as follows:

T-stat-----AH-----HP
R-----------R------R
Y1---------Y1-----Y1
Y2--------no connection
W2----linked to E on T stat
E-----------W2----W2out
W1 no connection
Y2-----no connection
G-----------G
O-----------O-------O
L---- no connection L-- no connection
C----------Com------C

As a result, I am not sure if back up heat only comes on full or in stages. Any idea why the large pipe going into coil in AH would be very hot and air not so hot. Does seem to be working better today. Also, my unit is a single stage HP. Does that change your tstat setting #3?
Thanks,
Mike

You had listed W2 twice?
Looks like the page did not space it out. The are connected to the t-stat.

AH-----HP
Y2-----Y2out
W2----W2out
Y2-----Y2out

I would suggest to have it rewired up as I posted.


Any idea why the large pipe going into coil in AH would be very hot and air not so hot.
Blower speed may be set too high.

Also, my unit is a single stage HP. Does that change your tstat setting #3?
No, Stage 1 is your heat pump, and stage 2 is your electric heat.

Ron,
Thanks for the info. If I understand the impact of how my system is wired by my contractor, two things will happen:

1. No diagnostic light.

2. With the aux differential on tstat set at 2 degrees, whenever the tstat is greater than 2 degrees higher than the room temperature, the aux back electric heat (emergency heat) will come on regardless of the outside temperature. If it was wired correctly, the aux would not come on above the balance point.

Has it been proven that HP tstats should be kept at one temp all the time or atleast such that the aux back up does not come on to recover the room temp?
Thanks,
Mike

1. No diagnostic light.
L is your "Trouble" light, if something wrong outside, it will send power to L, and turn on back up heat.

2. With the aux differential on tstat set at 2 degrees, whenever the tstat is greater than 2 degrees higher than the room temperature, the aux back electric heat (emergency heat) will come on regardless of the outside temperature. If it was wired correctly, the aux would not come on above the balance point.
Correct.

Has it been proven that HP tstats should be kept at one temp all the time or atleast such that the aux back up does not come on to recover the room temp?
Thanks,
Correct.