As teammates huddle in front of the engineering closet, veteran Jeff Lyng hovers over their shoulder. "You have to be inspected at 7 a.m. tomorrow?" he asks Spencer, who isn't sure. "Will you be penalized for installing the hot water tank?" Spencer isn't sure about that, either.
To fix whatever's wrong, they need to access hard-to-reach wires and pipes inside the closet, and they can't get the side wall to slide out even after they take down a ceiling panel to make room. "This competition's worth more than a piece of wood," Lyng says. "Just cut it out of there."
Baum does just that, grabbing a power saw and slicing a big, crooked corner that will later make architects cringe. "That's what I'm talking about," Lyng says.
While one student rewires the heat pump, McNeill's father, who's dropped by to visit, takes a wrench to the pipes, trying to stop any leaks. The incorrect piping has somehow affected the heating and cooling. The team should still be able to make hot water by having the heat pump send water directly to the hot water tank, but it's not working and McNeill can't figure out why.
Corbin calls out a warning: They have to be out of the house in thirty minutes.
Brandemuehl appears for an update.
The heat pump's shorting, Spencer tells him.
The students fill their advisor in on the possibility of a backup electric water heater, and he shakes his head: "I would prefer to get the heat pump working."
What was supposed to be an elaborate control system is now just a couple of guys standing by the fat wall flipping switches. Spencer remembers two wires he had disconnected, and reconnects them.
"Okay. Ready? Give it a shot. Turn on 6."
"It's not on, turn on 22."
"Can you turn on 6 again?"
No, because a fuse has blown.
They scramble to find a volt meter that will tell them which wire has too high a voltage and is causing the short. But it's too late.
One minute, Corbin calls out.
"Everybody out!" Brandemuehl says. "Let's go. We're done."
Outside the house, most of the team members stand in a circle in the dark and discuss strategy. If they decide on a hot-water backup, Brandemuehl will go to Home Depot — though he clearly wants the students to get the system they designed working. And that's what they decide to do. They'll meet tonight to go over drawings and come up with a plan. Baum sits away from the rest, hanging his head. He has to return to Colorado, and he hasn't accomplished what he came to do. The house hasn't yet passed electrical inspections.
The next morning, students are back at both the fat wall, trying to determine why fuses keep blowing, and the mechanical closet, trying to figure out why water won't heat. McNeill thinks there's too much air in the pipes and is using a hose to add water to push air out. But because the controls aren't working, the only way he can determine the temperature of the water and the amount of the flow is to feel the pipes. "We're getting some air venting," he says.
"Okay, there's heat."
Spencer is smiling and giving a thumbs-up sign, like they've finally figured it out — and then he looks over at the hot tank: "Hey, how come there's water droplets here?"
Just as he asks that, water pours over the top of the hot tank and into the kitchen. McNeill has added a little too much water to the system.
While they dry the spill, McNeill fiddles with valves, determining which he must turn to stop water from flowing to the hot tank. He picks two, but doesn't seem that confident in his choice.
Corbin is standing on the ladder with his hand in the tank so he can feel if the water rises again. He marvels at how his hand is in water but not wet because of the tank's nanogel insulation.
Tom Meyers, the contest superintendent, is due any minute for their inspection.
"Is this going to be enough?" McNeill asks. "We got a guy with his hand in the tank, and we might be spilling water that's 150 to 200 degrees on people."
There's a crackling sound as the heat pump is turned on again.
"Something doesn't seem right here. Can we shut it off?" McNeill calls out.
A middle-school class shows up with a camera crew at their scheduled time to tour the house, and Corbin decides to turn them away.
They flip on the heat pump again. More crackling.
"What is that?" McNeill wonders aloud.
"Are we there yet? Are we there yet? Are we there yet?" Brandemuehl asks, bouncing like a child.
They decide to adjust the flow rate, then turn the heat pump on and off again, and again. Everyone is touching pipes to try to guess their temperature and flow. McNeill realizes that the pipes on the cold side of the system are "cold cold" — but not in the right places.