I got snookered big time...
Hey all, first post.
I recently bought a house (8 months ago). It has a Nordyne 5 Ton split system heat pump with 30kW of backup heat (all electric). The home is newer, well insulated, with Insulated Concrete Form walls. Single story with finished/heated basement. I have about 1900 square feet upstairs and a little less (1700) downstairs all heated and cooled by this system. I also have a 30,000 BTU ventless propane fireplace in the living room upstairs.
Oh, and the house is located in the mountainous region of western/central Pennsylvania. I think we have something like 7000 heating/degree days. It's a colder climate, but not like Minnesota cold. My heat bills were pretty high this winter, even though we posted the mildest winter on record. I mean it was like spring temps all the way back in mid January. Crazy. When I bought the house, I was quoted an average electric bill of $150-175. Well, the cheapest summer bill we had was $160 which was in September and the highest about $214. Then fall/winter hit. $250, 300, 300, 350, 400, 200. That's Oct-Mar bills. Now if we would have had a *real* central PA winter I would have been thrilled with those prices. However, it was very, very, mild and I expected to do better (at least as good as that 150-175 average they gave me).
So I did a little troubleshooting, and quickly found out that no matter what I did, the compressor/fan in the outdoor heat pump would not turn on. I waited for the reset time, reset the power, and the thermostat had no emergency heat setting so I knew it couldn't be that.
So I removed the cover on the electrical disconnect on the heat pump to see if the fuse had blown or breaker had tripped. It measured OK… but I noticed low voltage wiring in that box with e-tape on the wires and no wire nuts. At that point, my instincts said call a professional, so I did.
A few days later HVAC tech from a local reputable installer/repair place shows up (not the original installer). I show him what I found and he makes some concerning sounds "hmmm, oh boy, eeks." He says, let me look at this and I'll see what I can do. About an hour goes by and I hear two voices in the basement. Well, turns out he calls his service manager to show him just how bad it is. I talk to the service manager, and he says, "Ryan, you might want to sit down for this."
First we talk about the wiring to the outdoor heat pump. Five splices, thermostat wire run in same conduit as 240V, heat pump not even wired to turn on! It was hardwired for cooling ONLY! Some of the wiring was just wrapped around the metal terminals (no wire terminators, crimped connectors or anything).
Next he showed me the return duct trunk. There was only one trunk, a 20x8 duct for the whole house. Based on what he calculated, it was 50-60% too small.
The new contractor I called in ended up fixing the thermostat wiring and adding additional 18x18 return ducting in the basement. They also replaced the indoor thermostat because it was the wrong kind. This increased the airflow through the unit, and enabled the outdoor unit to actually function as a heat pump.
Later I went over the installation manual like a hawk. According to the system spec from Nordyne, the three supply circuits should have a minimum ampacity of 59A, 50A, and 25A respectively. The installer used two runs of 8/3 (wg) for this. Red and black of run #1 fed circuit A, red and black of run #2 fed circuit B and the white wires from both runs fed circuit B. The outdoor unit was piggy backed off of circuit C inside of the air handler, by just wiring the 8/3 run from outside to the supply side of the circuit C breaker.
The new contractor didn't catch the #8 supply wiring, not that I blame them with everything else so out of wack. I'm not sure if it's up to code or not or even acceptable. The one table in the older Nordyne manual states #6, #8 and #10 for the three circuits if 75C rated wire is used. I believe at a minimum I should upgrade circuit A to #6 and wire the outdoor unit on its own circuit.
Also, the original installer blocked access to the filter door with the way he routed the return ducting, so he just cut a new hole in the back of the air handler for access to the filter. Boy is it a pain to remove that filter because of that.
Lastly, no outdoor thermostat was installed to force the unit to switch over in extreme temperatures so that needs added too.
Basically I think it was a total hack job of an install. I'm also looking into whether it needs a crankcase heater or other options that were probably not even thought about.
Thanks for sharing.Let us know how it goes.
Wow! that's a lot of typing, should have uploaded a YouTube audio/video.
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Sorry for the lengthy post. Pictures would have told the story better, but I didn't take any. The HVAC tech that fixed it took some but i forgot to get them from him before he left. Maybe they'll show up on this forum LOL.
I wish there was a way to find out who did the original install.
Local Nordyne distributor could probably tell you if you gave then the serial number of the unit.
Usually, 30kw needs 3 60 amp supply circuits, #6 romex each. That's just for the heat banks, the outdoor unit should go to its own breaker in the panel. The equipment sounds way oversized if the lower level is basement. Usually you size the outdoor unit for cooling and heat strips for heating. Here, where we size to -10 out, we'd likely have 2.5 ton for 1900 sq ft well built on a basement. 15kw would likely do the backup but 20kw wouldn't hurt. Most people don't use an outdoor stat to lock out the heat pump in the cold but with that monster backup, I'd lock out most of the strips until the most bitter weather.
We are not supposed to give definitive DIY advise on this forum, however I can say from reading your post... you are on the right track.
Couple of comments:
Your contractor seemed to understand what to do... might build relationship with him if your gut says you trust him.
I would have the contractor address the electrical first... then
One cannot have too much return air, nor too large an air filter (within reason of course). Might address both of those when some extra $$$ is available for your contractor to do so.
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Quality work at a fair price with excellent customer service.
An ICF house should not need that much heating capacity! The return air addition was a great investment, sounds like the guy you found knows his stuff.
On a side note, I don't see why ICF house builders put in such large systems, it's like they don't trust their own materials. I just picked up a guy that does ICF homes and required a Manual J and manual D then I show him it's a 2.5 ton size and guess what, he tells me no put in a 4 ton that's what my last guy used. I refused the work saying its sized based on what you asked for. Fortunately for both of us we still ended up doing the work last week.
Moral of the story, just because high efficiency methods are used does not mean the builder will know how to use them/size them right.
Sorry, I meant 25 kW... I checked it, again, and the install manual says one #6, one #8 and one #10 for a 60/50/30 but it specifies a 75C rating for the wiring. If it's 60C then it specifies #4 #6 and #10.
Originally Posted by BaldLoonie
I also have 1700 sqft of finished and heated space in the basement if that matters WRT equipment sizing.
so why did you choose the second guy over the first?
not confident in their ability, cost too much compared to the second?
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Not sure what you mean... there was no "second guy" to choose.
Originally Posted by pacnw
I called XYZ heating to come and take a look at the system. Their tech called in his service manager because it was so bad. I have no idea who originally installed the system. They left no sign of their work. For instance, my parents furnace has a sticker on it "installed by yadda yadda yadda..." To be honest, given what I've learned reading about the system, proper duct work, electrical and otherwise, and from talking to my HVAC contractor, I'm glad I didn't call the original installer. They probably would have continued to overlook the issues while I flushed money down the drain.
I was pleased with the new contractors work, other than missing the wrong size conductors on the air handler heating element circuits, which I can't blame them for really. It wasn't dead obvious, I only noticed because I decided to read the entire installation manual front to back and make sure the thing wasn't going to burn down my house. It's been here for ~6 years so it's probably not going anywhere. That said, the #8 conductors could possibly suffer damage over time I'd imagine.