Wiring messed up?

[karmana]

Quick & Dirty Summary:

Make: Coleman Furnace/HeatPump system (indoor/outdoor.) Model on indoor unit unknown- yellow sticker about 90% torn off. Outdoor unit shows: Model Series 3400.
Thermostat: 3AAT82B13E1
Identical t-stat pictured here:

http://forum.doityourself.com/showthread.php?t=323544

*EDIT* My t-stat has a slight difference from that pictured there. W2 has a grey wire, and A has a brown wire. I have blue, pink, & black wires that are not connected to anything at either end. Where the t-stat wires connect to furnace harness, they are all matched to identical colored (but larger guage) wires, which feed into a metal box mounted onto the blower unit. **End Edit**

Purchased used manuf. home. HVAC system was butchered... Electrician fiddled with wires at thermostat to "at least get the emergency heat working" for us (we live in NorthEastern WA.) MUCH later, get entire unit up, charged, running, no leaks, etc. Setting it to COOL/AUTO/NORM blows HOT air! (We have been running on EmHeat for 3yrs...)

I can see the R22 moving at the sightglass, and can feel its' heat at the indoor coil, so I know it is "running backwards." How should the thermostat be wired to correct this, if that is indeed where the problem lies? (I suspect it to be in the electrician's fiddling 3 yrs ago, to help us out THEN.)

ps- have not tried COOL/AUTO/EmHeat... didn't want to take chances and screw it up.

-Kar

pps- after frying my "lifeline plug," found replacement parts through you guys... Thanks! Now to get the air going right direction...

[karmana]

I am trying to track down the terminal codes for the thermostat, and have discovered 2 things- that they were standardized in 1972, yet this is a 1971 heat pump... So I have a "Terminal A," which is not listed ANYWHERE! Please help! I also do not have an O, B, etc... orange wire is connected to terminal "X," which is also not a standard terminal... I seem to have the right number of terminals, but am not sure what X or A is for...?

*Note, while HVAC tech fixed unit, charged, etc, I dripped water on "lifeline plug." The red 1 + orange wires shorted, causing constant power to switching clear electric box outside (constant clicking, HVAC guy identified for me.) Was not left doing this- killed breaker- fixed wires- no constant click, but now no apparent reversal either... help!

[karmana]

Looking at the back of the thermostat:

3 switches- H/O/C, A/O, N/E
H/O/C = 8 pole
A/O = 3 pole
N/E = 6 pole

H/O/C:
(from top left to right)
Pole(p)1: grn wire to 'blank' terminal
p2: connects to Terminal "Y1" & p2 on N/E
p3: connects to "W1"
p4: blank terminal
p5: con. to #1 on A/O
p6: con. to "V"
p7: con. to "W2"
p8: con. to blank term.

A/O:
p1: con. to #5 E/H & #5 H/O/C
p2: con. to "G"
p3: con. to #3 E/H

E/H:
p1: con to #1 A/O
p2: con to #2 H/O/C
p4: con to "A"
p5: con to #3 A/O & E/H red light

**NOTE: Terminal "X" connects ONLY to a small transister looking thing (like a mini cylinder with a pin sticking out of top & bottom), which is in turn solder-linked to the opposite pole of the E/H red light (see E/H "p5")

I am suspecting that my orange wire, which SHOULD connect to the reversing mechanism, is miswired, since it is connected to the "X" terminal- and appears to be in no way attached to the C/O/H switch...?

[Robert]

Hi,

It will run in reverse heating mode unless t-stat is set to Cool-Auto-Norm.

However, you would need an O or the reversing valve relay wire would need other designation to energize when cool mode is chosen.



Best advice here is to get a qualified HVAC Tech, not an electrician, to diagnose any problems and correct wiring as needed.



Take care and best wishes,
Robert

[karmana]

It will run in reverse heating mode unless t-stat is set to Cool-Auto-Norm.

Thanks, Robert. In the quote above, if you replace "unless" with "when", then you have exactly my situation... When it is in Cool-Auto-Norm, it blows heat, with the heat pump in operation. In Heat/Auto/Em it blows heat, w/o heat pump in operation. The Cool/Auto/Norm doesn't seem to be working.

I talked today to the HVAC tech that was here the other day, he suggested just disabling the orange wire TO the heat pump at the indoor furnace (wire-nutting it off) for now, saying that would force it to run in Cool mode, since the relay would not then get the call to reverse to heat. Does this sound correct?

[Robert]

Hi,

Depends on whether the default is set to heating or cooling mode.


Why did he leave a unit in an inoperable state ?



The norm is for the reversing valve solonoid to be energized when

t-stat is set to cooling/auto and it switches from heat to cool mode.



Thanks,
Robert

[karmana]

He'd left it inop because I myself fried the 15 circuit molex plug that sits below the drip tray... (when cleaning the indoor coils at his suggestion; didn't realize the drain was plugged!) When that happened, the red and orange wires on that plug shorted together, simultaneously causing a rapid click at the outdoor unit, at one of the relays- he said it was the reversing relay. Apparently none of the local hvac shops up here are aware they can buy (and then rebuild) their own molex plugs... instead, ordering "pre made" units for much more $$. I ordered the plug/pins through you, rebuilt plug (wires replaced in exact same positions as original.)

I am wondering if the short inside, may have damaged the reversal relay outside, OR- there was a moment where a pin he'd replaced shot out, the freon burned his hand, and some freon was lost- could that be the problem as well (too much lost?)

*Note, I did just try it with the orange disconnected at furnace; no change. NO setting blows cold air. Changing to Em. Heat DOES turn off the outdoor unit as it should. The thermostat is also reading temperature correctly- even though its not blowing cold, it will only come on when in cool mode, when I move the temp slider below the room temp.

[Robert]

Hi,

I'd say the short damaged the reversing valve solonoid relay.

That would be my first suspect.


Those molex plugs and wires are like vehicles. You can go to auto parts store and get wire and terminals and make wiring harness OR go to dealer and order wiring harness for excessive $$$$$$$$.



Take care and best wishes,
Robert

[karmana]

Thanks, Robert. My next question, is, any idea which replacement one I can use? Mine LOOKS exactly like your "1460-3771 Dual Fuel Control Relay" shown here: http://www.mobilehomerepair.com/media/i ... 0-3771.jpg and that is the only "relay" of that sort I see?

I am going to have them come out this week, and want to either use your price to keep them reasonable, or just get it from you and go from there (if they determine that IS the problem.) Don't want to .05 & .10 myself either!

*edit: The only model type number I could find on my relay (which has a tan/milky residue on the inside, 'top' of the plastic cover... unlike the other 4 or so in the outdoor unit,) is 74-303-737-45, with a red-stamped number below that of "8321".

[Robert]

Hi,

Will need complete model number of heat pump to give parts info.


What type furnace heat source do you have inside ?


Thanks,
Robert

[karmana]

Will post what I find in the morning. The entire system is Coleman; I haven't been able to find a model number for the indoor unit, though each component seems to have its own part number clearly labeled... (original door missing; the door included when received, obviously is not correct.)

Do those clear relays just pull straight off, or do I need to remove the circuit board first, then remove it? (would make reading the numbers on THAT much easier...)

(I repair PCs, not A/Cs... heh)

[Robert]

Hi,

That is a defrost relay and is part of a dual fuel system.

It is not the reversing valve solonoid relay, it is part of the reversing valve.


The relay you have could also be part or all of problem, depends on how circuit is run and what was damaged by shorted circuit.



Thanks,
Robert

[karmana]

Ok, here are the only solid numbers I could find (both found on a tin plate, stamped).

Heat Pump-
model: 3437A601
serial: 118308750

Heat Pump Coil:
model: 3440A830
serial: 028400083

The relay with the tanish-milky residue has these numbers:

Coil 24v 50/60hz
3230-386
Contact Rating:
125va/250v 60hz
5a 125v 3a 250v 60hz

[Robert]

Hi,

I checked on all relays and the reversing valve solenoid coil and none are available any more.

There was also no replacements that I could find.


All relays in that series timeline for similar units that were available were all $300+ so it would have been pricey.


Your best chance is to find a reputable and qualified HVAC Tech who can use universal relays and such to "possibly" get it going.


Now, with said, it will also be pricey for labor due to age of unit and problem finding parts to work.



At that age, best solution would be a replacement Heat Pump. The efficiency increase would pay for itself in a few years.


Lowest seer rating today is 13 seer, yours is a 8.5 seer .


That would be a 4.5 seer minimum increase.



Take care and best wishes,
Robert

[karmana]

Thanks, Robert. I am searching for matching replacements, and seeing a vast number of different names for the same part! Contactor, relay, "plug in, sealed," etc...

Found: "Coil: 24V 50/60Hz - Contact Rating: 1/10HP @ 125-250V 60Hz / 5A @ 125V / 3A @ 250V 60Hz"

With the omission of the "1/10HP" on mine, I'm not sure if these are the same or not?

(I realize pin/blade configuration must match up correctly.)

*EDIT*
Robert, if I take some pictures of several components, can you tell me what they are? I can follow simple wiring logic, as long as I know what each component IS.

I have so far identified:

What I have:
Terminal Wire Color Purpose
G Green Fan blower
Y1 Yellow Compressor (Cool)
V White UNKNOWN
W1 Yellow (from Y1) Compressor (Heat)
X Orange UNKNOWN- Common?
R Red HOT- 24v Power IN
W2 Grey Second Stage heat?
A Brown UNKNOWN

System uses same compressor for both heat/cool, so Y1 & W1 are connected via jumper wire to energize simultaneously. This also means YELLOW wire is designated COMPRESSOR and not H/C individually.

*Also- with Thermostat in Off/Auto/Norm, power ON at breaker, but nothing "running," there IS a buzzing noise at the square circuit board which holds 3 clear cover relays (defrost control board/ reverse relay area?)*