Hello there. I am currently struggling with a new home builder’s HVAC contractor to fix some brand new ductwork and I am looking just for a second opinion to spot check them. My issue is:

1. I have repetitive clicking/popping in my HVAC whenever the heat is running. The popping occurs roughly every 5-15 seconds and never stops.
2. After removing the drywall in my basement’s floor, the sound seems to be coming from the joint in the main long register, about halfway down the register.
3. The grey mastic/pookie surrounding the joint is already 33% of the way cracked after less than 3 months of real use.
4. The HVAC company remarked that the metal in the register/joint might just be defective and that “Some just show up from the factory like that”. Rather than replacing said metal, they are repeatedly trying to brace the register in 2 different rooms with horizontal metal bracers.

I am starting have incredible apprehension that the HVAC company is going to take the cheap route out, finish bracing the metal enough to not bother us (since its starting spring warm up) and then vanish until after my warranty is over.

My question to you is “Is it unusual that mastic/pookie is already cracked after 3 months? Will this provide a poor seal for air loss once the drywall is replaced? Finally- if you were in my shoes, would you personally mandate that the register be replaced or would you trust in the HVAC company’s expertise?”

THANK You so much in advance for your help.

You can find this problem with undersized returns and insufficient air flow. Negative pressure sucks the duct down and it "oil cans". Bracing can stiffen the duct. Have them do a water column test across the plenum. Have them put more mastic on.

For one, they screwed you because it isn't even insulated. They screwed you buddy, you always insulate duct if AC is on the system whether it's in a basement or attic, no matter finished or unfinished. So you will get a line of from this company no matter what. Something may have fallen down into the boot or line when they installed it. We covered our floor registers after we cut them in to make sure debris didn't get into it. Sounds like if it's coming from a run, something fell into the run. Take the floor register out and see if it still does it. Then take the line loose from the trunkline (if you have no tools, duct tape will put it back) and see if the noise is still there. You got screwed my friend. ALWAYS insulate if air conditioning is on the system. Heat won't sweat the trunk, it'll just lose heat.

And yea, the return will pop if they didn't break the duct. If it's popping you can fix it by getting some cheap small gauge angle iron and screwing the angle in the middle of the duct from one side to the other. It's easy if that's the case, go to Home Depot and ask them if they have some light gauge angle iron. Go to the middle of each joint, screw the angle iron across it on each side. That'll keep the middle of the duct from "sucking in" and popping. If it's sucking in and popping, they undersized the return. Also, if you don't see slight bends in an "x" pattern across the duct, retards put your system in because you always break return duct from one corner to the other to keep it from popping. You don't know, guys start their own HVAC companies because they think it's easy and they can make tens of thousands in a month. They can. They don't know all the tricks. Angle iron, thin gauge, go to a sheetmetal shop and tell them your return duct is poppin in so you need some 90 degree pieces of metal to screw on each side of the duct in the middle of each piece. Ask them, they'[ll help you out and tell you. Sheetmetal guys take pride in what they do. Guys who buy ductwork and slap it in don't give a feck.

I forgot, pop 2 screws towards the middle of each piece of angle iron. A sheetmetal shop'll bend you some up for 20 or 30 bucks. They'll help you if you tell them your ducts poppin and you need to stop it from popping. You screw the angles to the duct and it keeps the middle from snapping in. If it's the top sucking in, you'll have a time getting it right. You may have to cut a hole in the bottom, screw the angle on the inside, then screw a patch covering your hole. I'd do that before I dropped the duct. That company doesn't want to go through the work of doing that. You break your returns from corner to corner.