Heating, Air Conditioning, Fridge, HVAC/heat pump

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inside terminal board
inside terminal board  
outside defrost board
outside defrost board  
QUESTION: This is my mothers home and I'm determined to get her heat pump running before I depart in ~10 days.

The AC has not worked for years, now it seams the heat isn't either, luckily this is Texas, but a very rural area and there is no help for hundreds of miles so I was extremely happy to find this site. Our internet is very slow and I have limited tools...

The reversing valve seams to have a good click/snap when activated in AC cycle, I do not have magnets to test it.

Just looking it over, I suspect it might not have worked since the thermostat was replaced several years ago and even so, there could still be something else malfunctioning.
Pictures are available here:
http://s1099.beta.photobucket.com/user/hlndrmt/library/heatpump

A few observations:
- the 7.5 amp fuse on the control module looks good.
- there is a very faint hum from the top of the blower unit where the electric heat coils are.  
- the outside fan does not operate in AC or heat mode, but the inside blower does go on.

Thermostat = Robertshaw model # 8425
Inside upflow blower (ignition control) = Bryant model # FK4CNB006000AEAA
Outside (defrost board) = Payne model # 812AN060-B

Using the inside ignition control module as baseline, here are all the pegs listed in order as follows:

thermostat – inside control module– outside defrost board
(where “x” is an open unused connecter peg)

x-DW-x
R-R-R
x-W1-x
x-W2- white wire *see below*
x-Y1-x
Y-Y/Y2- blue wire *see below*
G-G-x
O-O-O
C-C-C

*the white and blue wires* run to the outside unit but are not connected to the defrost board, they are jumped together with a dark blue wire that bypasses the defrost board and goes straight to a sensor located on the large copper tube running to the house, it then continues to the LINE side of a transformer, then a yellow wire departs the LOAD side of that transformer and runs to a second sensor on the small copper tube running to the house then from that sensor to the 120 volt power supply in the outside unit.

On the inside control module, there are 2 extra wires (white, tan) entering from the thermostat and 3 extra wires (yellow, green, brown) entering from the defrost board. All of those are open and not connected to anything at either end.

Here are the open not used connections on the thermostat.
W1
RC
WZE
and the 2 extra wires, white, tan

And obviously there are many open not used connections on the outside defrost board and the 3 extra wires (yellow, green, brown). As, you can see in the photo, the yellow wire has been cut and bypassed on the defrost board peg. I’m guessing this is bypassed by the *the white and blue wires*  mentioned above.

Thank you for any help!
Mat

ANSWER: Matt,
I can't diagnose your units on line and without a wiring schematic?
The R post wire on your thermostat is the hot power wire, when you set the thermostat to heat the power from the R post jumps to the W post wire, and you should get heat.
Take the R wire and the W wire off the thermostat and touch them together, see if anything happens?

Matt, check the thermostat wires from the thermostat to the outside units contactor,'It sounds like your contactor is not pulling in?

---------- FOLLOW-UP ----------

QUESTION: "Matt, check the thermostat wires from the thermostat to the outside units contactor,'It sounds like your contactor is not pulling in?"

Exactly. When I set the thermostat to heat or cool, the blower starts up but there is no change in air temp because the outside unit does not start up. When I go outside and physically press the contactor to start the outside unit, within seconds, the air temp drops/raises as per the demand from the thermostat. Everything works!! it is just not starting the outside unit.  I need to know which wire is set to call for the outside unit to start up?? My guess is that it is the strange wiring configuration I mentioned earlier, perhaps something in the defrost board failed, and it was bypassed as follows??

thermostat – inside control module– outside defrost board
> x-W2- white wire *see below*
> Y-Y/Y2- blue wire *see below*
*the white and blue wires* run to the outside unit but are not connected to the defrost board, they are jumped together with a dark blue wire that bypasses the defrost board and goes straight to a sensor located on the large copper tube running to the house, it then continues to the LINE side of a transformer, then a yellow wire departs the LOAD side of that transformer and runs to a second sensor on the small copper tube running to the house then from that sensor to the 120 volt power supply in the outside unit.
So I think we have it nailed down to 3 possibilities:
One of the two sensors has failed.
The transformer has failed.

My next step is to bypass each of the two sensors. I don't know how to test the transformer, any suggestions?
I wish I had a mutimeter! I've checked the stores within 30 miles.

Answer
Matt,
Wire colors don't mean anything other then a way to identify the wire on each end.
The low voltage thermostat type wires 24 volt that run from the inside unit to the outside unit usually along with the refrigerent lines are what actavates the contactor in the condensing unit, when the thermostat calls for heat or cooling one of the wires should be hot 24 volts.
when the thermostat isen't calling none of the wires are hot,
you can take the low voltage wires off at the contactor and touch them togeather with the thermostat calling and you should get a spark, if you get a spark the contactor is getting power, if no spark theres a break in the wire.

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Jim Barnhart

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Answer questions about , residential and commercial. Answer questions about sheet metal fabrication. Fifty years plus experience. No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances, I don't specialize in one particular area of the HVAC area, I'm more of a General Practitioner, Limited in refrigeration/

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