My new incorrectly wired heat pump

[eetommyj]

I just moved into a brand new 2 story 1680 sq. foot house with an unfinished/unconditioned 840 sq. foot basement. It has an open concept down stairs and three bedrooms upstairs. The house is being heated and cooled with a Goodman heat pump with an aux electric heat coil.

When I first moved in, I noticed the thermostat was in cooling mode set at 68 and the humidity was at like 64%. It was pretty cold. I put a dehumidifer in the basement and it was reading about 85% humidity. The builder also said to expect the humidity to be high since the house was new.

Another thing I noticed was that when the heat pump cycled, it sounded like a hurricane. The vent noise was loud enough to make me think it was raining outside.

I checked the stickers on both the outside unit and the air handler. The builder left all the manuals for the equipment so I was able to check the size ratings. The builder installed a 16 SEER Goodman SSZ160361 (3 ton model) with a Goodman AEPF426016 Air handler, which supports heat pumps from 2.5 to 5 tons. They also threw in a nice fancy Climatouch thermostat.

The AEPF air handler documentation states that its factory default DIP switches set cooling/heat pump heating modes for 2000 CFM/5 ton. I would expect that this setting was set for 1200 CFM/3 ton to match my outdoor unit.

Out of fear and curiosity, I thought that maybe this setting was overlooked so I shutoff all the breakers and pulled the cover from the unit and looked at the DIP switches. The DIP switches were at factory default :eek:!

Fearing that the 2000 CFM would ruin my duct work, I changed the appropriate DIP switches to the 3 ton (1200CFM) setting. I also took a quick look at the air handler/thermostat wiring and I found that the installer never removed the factory jumper between O and Y1. The documentation states that the jumper is only needed when the air handler is used with A/C-only condenser.

This jumper would explain why my heat pump outside unit would kick on and cold air would come out of the vents the moment I turned on the thermostat's heat mode despite the temperature being more than 10 degrees about the heat set point. The installer apparently set the Climatouch thermostat was set to energize the O relay when it is in heat mode to compensate for the incorrect wiring.

I made the changes on Saturday. The humidity now is around 58% and I'm trying to keep the temperature at a more comfortable 74F. The basement is now around 65% humidity as well.

Well, needless to say I have little confidence that the heat pump is installed correctly. The house is still under warranty and I know I should report this to the builder. However, since they did such a terrible job with the air handler wiring would it be better to have an independent HVAC installer look at it first? If I do call them, should I put the wiring and DIP switches back to their incorrect settings?

[BaldLoonie]

Typical workmanship in new construction. Sad that the HO is smarter than the installers (or maybe just cares about the result) but at least you have a functional system now. I would leave the stuff where you have it set correctly but certainly tell the builder (not sure he cares either) about the incorrect settings.

The biggest drawback to excess air is noise and lousy dehumidification. 3 tons for 1680 sq ft seems a lot. Are you in a hot climate? Lots of windows?

[forcryinoutloud]

You can get the installing contractor back out and explain to them your concerns, or if you don't trust them you could get a different contractor out to check over the system for you.

If you choose a contractor other than the original installing contractor to check over the system the installing contractor may void their labor warranty with your system.

Either way I would definately have somebody other than the builder (General Contractor) look at it. Most don't know what they are looking at any more than you do.

[Airmechanical]

with that fan adjustment you made, surely the refrigerant charge will need

to be adjusted to accomodate the new fan speed

the way that you say things were done

the refrigerant charge was probably not correct to start with anyway

good luck



.

[Freezeking2000]

with that fan adjustment you made, surely the refrigerant charge will need

to be adjusted to accomodate the new fan speed

the way that you say things were done

the refrigerant charge was probably not correct to start with anyway

good luck



.

If the installers cant set a dip switch, you know they do not know sub-cool or superheat. Call the owner of the install company and tell him you need a service tech to come over. Tell him what you found.

[eetommyj]

It's my understanding that the unit was sized for heat load rather than cooling load. I live in Northeast PA, in the Poconos area so winter and cold weather dominate the year, though I live in the valley so I don't get get the terrible winter weather that the higher elevations (like Mt. Pocono or Gouldsboro) do.

I did not want any combustion heaters, so I had them install electric auxillary heat. They stuck in an HKR-15C* 14.2 kW heat kit, which I think runs around 48,600 BTU. The documentation says to set the aux/emergency heat DIP setting for 1600 CFM when using this heat kit. Guess what! It was set at the factory default of 2000 CFM.

Well, I'll contact the home builder and see what they say. From what I can tell, they subcontracted the install of the mechanical portion to one company and the electrical portion to another.

[edit] Oh and to answer BaldLoonie, yeah we have quite a few windows in the front (south end) of the house. Six 3' x 5' windows on the south of the house, a window seat in the front dining room (3 smaller windows) plus a large picture window above the front door with twin side windows beside the front door.

The back of the house has a sliding door plus four 3' x 5' windows.

The left side of the house has one lone small octogon window, and the other side has an insulated 2 car garage.

The exterior walls are 2x6 filled with an insulation called GreenFiber Cocoon. It's recycled newspaper with fire retardant or something like that. It's supposed to fill in the gaps better.

[RoBoTeq]

Over sizing for heat was a bad idea, but with the system you have it can be dealt with.

That air handler blower can have the airflow reduced 15% with the dip switch settings. That will help with the lack of dehumidification due to the oversized capacity. Also, a standard humidistat can be mounted to the return duct and wired in so that the blower will decrease even more if humidity is high.

I would also check to make sure the wire connected to the Y1 terminal on the air handler board (usually purple) is not connected to anything outside of the air handler.

Did you request this upgrade? Sounds like the installers may be used to builder model systems which don't have any of the things you are finding wrong. Having contractors install what they are not used to, unfortunately, can result in these sort of issues.

It's a good thing you found problems. It may be best to have the installing contractor send out a qualified technician to fine tune your system.

[eetommyj]

I originally wanted to install a geothermal system, but they were so expensive that the bank would not give me a loan to build the home with such a system. Economically, geothermal seems to be more appropriate for 10,000 sq. foot McMansions with vaulted ceilings or for large commercial office buildings where you can recoup the cost of the system quickly. So, an air source heat pump was the next best thing.

I asked the builder about the Hallowell Acadia 2-stage heatpumps. The home builder's HVAC contractor said that the Goodman was theoretically just as efficient but the equipment cost was much more reasonable. The Goodman SSZ16 spec sheet claims that the 3-ton heat pump and the model airhandler I have can get an HSPF as high as 9.75, provided (of course) it is installed and sized correctly :rolleyes:.

With my system I got a Climatouch thermostat that has a humidistat built into it. I was going to ask the builder to come back and hook that up so that when the humidity is above the setpoint (say 45%), the airhandler will slow down to 85% CFM (so about 1020 CFM).

[eetommyj]

I talked with the installer today and it turns out that his company is actually a plumbing/heating business. He had Goodman specify the required parts and he installed based on their recommendations. He's having Goodman mail him some documentation. Sometime next week, he said, he'll stop by and help me figure all this out.

I have a bad feeling about whether the system has been charged properly. Depending on how the visit goes, I'm thinking of hiring a proper HVAC company and to have a real HVAC tech come out to check out my system and tell me if my system is properly balanced and charged.

This is what I get for wanting a high-tech non-fossil fuel HVAC system in semi-rural Pennsylvania...

[flange]

In that part of NE pa, it has been customary for years to only install electric baseboard heat with no ac. Lately they have been installing a lot of different systems with the influx of people and the new development occurring. A lot of homes are now using radiant infloor heat, and some have central ac. The guys that were hired for this project may be a bit behind the curve, but at least give them a chance, most are honest and willing to help out. Ask them what method of charging they use for your system, and to explain to you why and how it occurs.

[eetommyj]

Yep, a lot of houses have resistive electric baseboard heat because the system is one of the least expensive in terms of inital equipment cost. Many of those same people have found that the cost of heating their homes is insanely expensive. It's also popular for such homeowners to have unvented kerosene heaters and they crack a window for the heater. Their air quality has to be terrible if not lethal. I'm surprised more people don't die from CO poisoning.

I am giving the installing contractor a second chance, but if these guys turn out to be absolutely clueless what other choice do I have but to seek a proper HVAC company? I see this as a learning opportunity for them, but hopefully it doesn't end up costing me money in terms of higher energy bills and maintenance costs due to flawed installation. I hope I can catch and correct all the problems early enough so that all I have to do for maintenance is change the filter once a month, have the coils cleaned once a year (or however often they should be cleaned).

[mark beiser]

Just a WAG, but I'm guessing that they didn't run the system in first stage and adjust the TXV to the required superheat, and charge to the required subcooling, as specified in the instructions.

[beenthere]

Just a WAG, but I'm guessing that they didn't run the system in first stage and adjust the TXV to the required superheat, and charge to the required subcooling, as specified in the instructions.
I don't think that 3 ton is 2 stage.
I thought it was only the 5 ton in Goodman that was 2 stage.

[mark beiser]

I don't think that 3 ton is 2 stage.
I thought it was only the 5 ton in Goodman that was 2 stage.

Hey, you're right!
We've installed several of the Amana ASX16 and ASZ16 systems, and I thought the Goodman SSX16 and SSZ16 were the same, except for the top and badge. Turns out they are not.

Thanks for the correction.:o


I still feel safe in my guess that the TXV was never adjusted though.;)

[beenthere]

I still feel safe in my guess that the TXV was never adjusted though.;)

Thats a definite possibility.

[eetommyj]

I will make a note to have the TXV valve checked. I'm perfectly comfortable with checking the control wiring and DIP switch settings, but plumbing, refrigerant charges, superheat temperature, sub cooling temperature, is way beyond me.

I don't want any work to be performed while I'm not there so I'm having the installer come out next week. I'm stuck at work this week and most of next week. I'll keep the thread posted as to what I find.

One further observation I have is that in the air-handler there is what looks like a large gray plastic drain pan on the right hand side of the unit. It interferes with me putting the cover back on the front of the unit. I would suspect that the pan is supposed to be there if unit is mounted side ways, but mine is mounted upright. Is that pan supposed to be there? The airflows out the top of the unit and the return duct is at the bottom of the unit. It has a 16"x20" filter in the return duct. When I get a chance I'll take and post some pictures for clarity.

[jumpit]

Kudo's to the homeowner, great effort. You actually read the install instructions. I do not know why more people don't. I guess they use them to put their knees on while working. :rolleyes:

[57Oaks]

I just have this system installed for my new house but I am not sure if it is working correctly (as far as wiring)! the system has a heat strip backup. How do I know when the backup heat strip is activated?

[RoBoTeq]

I just have this system installed for my new house but I am not sure if it is working correctly (as far as wiring)! the system has a heat strip backup. How do I know when the backup heat strip is activated?
You get warm:D

In a way, that smarta$$ answer is correct. When the auxilliary electric heat strips are activated, the temperature of the air from the vents will increase. You should also have an indicator on the thermostat indicating that the auxilliary heat is activated.

[jpb2]

It's a frickin Goodman it probably will not work for long anyway :)













jk

[RoBoTeq]

It's a frickin Goodman it probably will not work for long anyway :)
jk
I once saw a 15 year old Goodman using a Ruud that died in two years as a pump up base. Maybe that's the key:p

[jpb2]

Not often lol :) have a good week