Heat pump question

[fordfitz]

I have a goodman 3 ton 16 seer heat pump system. It works good in cooling. But when I select heat on the thermostat the condensing unit never comes on. The only way to get heat is with the heat strips. Anybody got any pointers?

[jimbo]

A heat pump, especially and upgraded 16 SEER model, is complex, and not an amateur DIY project. You have obvious things like the T-stat or a bad reversing valve, or reversing valve coil. But then it gets complicated. You probably should find a good service company to work on this for you.

[fordfitz]

I dont understand why it would be that complicated. I took off the outside cover on the condensor and broke out my multimeter. Looking at the relay that gives the 240v to compressor. It does not appear to get a signal from anywhere to trip the relay in heat. I took a jumper wire and jumped from the w2 24v terminal to the relay. Guess what it started up. Now I am wondering about the circuit board that all the wires plug into. The only wire that goes down to the relay from there is the yellow Y wire. That is for cooling and it works. Does anybody have a wiring diagram of a SSZ condensor unit? Or how I can get one? I would like to see where it is supposed to get its 24v from?

[jadnashua]

Yellow is the normal control wire to turn on the a/c unit.

Red is the normal control wire to turn on a heating unit. Follow the red wire from the termostat. It will probably cause numerous things to switch so that the thing can run in a reverse cycle. There should be a wiring diagram that came with it. If it gets too cold, then it won't try to run the compressor, it will trip the resistance heat instead. That thermostat could be bad along with numerous other parts. That thermostat would go to either control the compressor or the resistance heat controls.

[jimbo]

I have access to installation instruction, parts list, and service manual. I think the installation, and service manual, have wiring info. I can't link them because they are on a secure website, but I could print it out and scan it in at home and post a pdf with photobucket. Give me the complete model number, just in case, although I think these pubs are blanket for all BTU.

[fordfitz]

I measured the R wire. It is 24V in cool and heat and off. Only when heat is selected then W2 the white wire gets 24V also. The exact model number is Goodman SSZ160361. THe inside is a AEPF426016 and the thermostat is a honeywell T8611G. I think that the problem is outside.

[jimbo]

http://img.photobucket.com/albums/v5...9/Mail0051.jpg

http://img.photobucket.com/albums/v5...9/Mail0052.jpg

http://img.photobucket.com/albums/v5...9/Mail0053.jpg


I hope the wiring diagram (051) is some help. I don't know which type of indoor system you are working with. The diagram of the all-fuel control board (053) and the general trouble shooting chart (052) should give you some idea why I referred to this as a complex system.

The service manual is 78 pages, so I can't really post the whole thing!


By the way, if you need a complete wiring diagram for connecting to a specific Goodman indoor unit, they are all in the service manual. There were just too many pages to post, but if you have something specific, I could dig it out. I also looked through the Goodman service bulletin index, and did not see anything pertinent.

I would suspect the compressor for this puppy is north of $650, so that is another reason to be very careful about "poking around" in a system like this.

Most Goodman stuff has a least a 5 year warranty, and your upgraded system may be as much as 10 years. If you might still be in warranty, why would you even mess around???

[fordfitz]

The reason is I dont have a warranty. I bought the house with this in it. I am afraid of being charged an arm and a leg for sombody to come out. I understand wiring diagrams. I am a aircraft mechanic and have to look at them all the time and shoot wires. Those first two pics I found in the manuals that were with it. I was just really looking for the condensor wiring diagram. I dont think anything is wrong with the indoor stuff. How would one go about getting a service manual? Can I buy one anywhere?

[fordfitz]

Well after going out there with paper and pen and drawing up a wiring diagram of that unit. The only way to trip the contactor is thru the yellow wire Y. So I got to surfing the internet and came across another forum with a different heat pump system but the same thermostat having identical problems. Turns out his was the thermostat. There has to be a jumper wire installed between E and Y1 from the factory. After almost breaking the thermostat trying to take it off the wall I open it up and find I dont have that jumper wire. I made one up and now it works great. Thanks for the help guys.

[jimbo]

Congrats for getting this figured out. You threw me for a loop, because I thought something died, and it turns out, apparently, that the heat function must never have worked, or strip heat only?

[hj]

Don't you love it when we get all the information except what we need to diagnose the problem.