It's time for our seasonal maintenance on our HVAC and the company we have been using recently got bought out. They sent out this kid who looks like he should be in home room right now but at first I'm not too concerned.

Then he opens the HVAC closet and yells "Ain't no frickin way dude!". We ask if everything's okay and he doesn't answer but a few minutes later it sounds like he's decided to deconstruct my home and says "what the heck is that?!". Uhh... You'd hopefully know better than I would... I am absolutely petrified and glad it's supposed to be cool tomorrow in case this child can't figure out how to put this thing back together. No questions, just amused/ terrified.

My hvac guy says my heat exchanger is cracked, I don’t believe him. Is he trying to scam me

Can this be salvaged? Yes all other RTUs were checked after finding this mess.

Following up on my original post. Really appreciated everyone’s advice and wanted to get your thoughts on the latest development.

Quick recap:
- ~10-year-old Goodman furnace (GMSS920803BNAA).

- During routine maintenance, exhaust CO climbed to approximately 110 ppm (140 ppm air-free) after 15–20 minutes.

- Contractor suspected a failing heat exchanger and recommended replacing the furnace for $4,900.

- No actual crack or damage to the exchanger was located.

- Follow-up testing also identified exhaust recirculation at the outdoor intake/exhaust pipes and possible airflow restrictions involving the zoning dampers.

- Furnace has remained off.

The update:

I contacted Goodman directly, and they confirmed that the heat exchanger’s parts warranty is still valid through 2036, even though I’m not the original homeowner.

The original contractor has now offered to replace the heat exchanger under warranty for $1,700 out of pocket, including labor, warranty processing, and corrections to accessible exhaust piping. Drywall work would be extra.

That seems like a much better option than replacing the entire furnace, assuming the heat exchanger is actually bad.

My hesitation:

They still haven’t identified a specific defect in the heat exchanger. I’m concerned about replacing it only to discover the elevated CO was caused by the venting, gas pressure, combustion setup, or airflow restrictions.

I’m trying to arrange an independent diagnostic before authorizing the repair.

Questions for the HVAC pros:

1. Would you authorize a warranty heat exchanger replacement based on these findings, without locating an actual defect?

2. What additional testing would you want to see before proceeding?

3. Assuming the exchanger really is bad, is $1,700 reasonable for the labor and accessible venting corrections?

4. Is there anything specific about this Goodman model that should influence the repair-vs-replace decision?

Updated combustion analyzer results and installation photos attached.

Thanks again for all the help!

I am renovating a property in SC. It’s down to studs, older house never had central before.

Would a mini split be able to heat and cool the house? Or should I just go central. It’s a rental property.

My fan is making noises and is a bit wobbly. Since last 3 years. Nothing has happened though but sometimes the noises increases and it's extremely annoying and scary what should I do. Will it fall?? I have developed a phobia and i wake up in middle of night sometimes to the noise

I'm not an HVAC professional but I am in the construction field specifically underground work. I've stayed in many many hotels and airbnbs over the last 20 years on the road. I just came upon something I haven't seen before. Its a shower vent with a hole cut in the top right corner. The fins wont move and it didn't have any screws holding it in place. I obviously took the vent out and it opened to a massive area behind the wall instead of any type of Duct.

What the Heck is that hole for and why isn't there a duct behind it? Pics included. Vent apprx 6.5' center.

Looking for a sanity check from anyone in HVAC. Im in a Pattaya condo, 7th floor, outdoor unit sits on the service balcony. Midea inverter, cooling only, installed 3 months ago by a local shop. Cooling is fine, electricity bill is fine, no visible issues.

The thing is at night when the room is quiet I can hear the outdoor unit go through what sounds like a brief cycle shift. Its a soft clunk followed by maybe 20 seconds of a slightly different compressor pitch, then back to normal. Happens roughly every 45 minutes to an hour on hot nights when its running continuously. During the day with ambient noise I probably wouldnt notice at all.

Nothing in the room suggests anything is wrong, vents still blow cold, no error codes on the display, drain runs clear. Install was clean, pipe insulation looks right.

Is this likely just normal low frequency inverter behavior at light load, or something I should actually get a tech out to look at before it becomes a real issue. Dont want to call out the install guy for nothing but also dont want to ignore something thats a 6-month precursor to a failure.

I have a Trane 80% efficient gas furnace, installed in 2013. Just this season, the gas will come on, then before anything else happens, it cuts off. But the problem is sporadic. At times everything works fine.

I'm using a current generation Nest. It's relatively new for me, so I swapped in my previous thermostat to see if the problem still happens and it does, so I don't think it's the thermostat. Even if I set the temp quite a bit above the current temp, the problem will happen.

There's also a musty smell coming from the vents, but I don't think it's related.

Before I make an appointment I want some opinions so I don't get scammed. I did email one company who said it might be a bad circuit board or failed igniter, but it seems odd that the problem would happen sporadically with a bad board or igniter - it seems like it would either work or not work.

I called out an hvac guy to the house to fix this heater in our back room. It was added from previous homeowners (I don’t know how old) when they turned the all season porch into a finished living room. There is no central air going here and it gets cold in the Midwest winter.

The unit stopped lighting, it had a gas line and small flame that kicks on blowing heat into the house. It tries to light but no flame kicks on.

What is this heater and is it fixable? It worked so well when it was working and don’t want to replace if I don’t have to.

I used to work around software startups, so moving into a local HVAC service business felt like a strange pivot at first. Earlier this year, I started helping modernize a small installation company that already had demand but was still running on very old-school operations. The biggest change came from tightening up quoting, scheduling, and financing options, and taking a closer look at which dealer programs actually helped us scale. One of the more useful moves was looking into a manufacturer’s comfort dealer program, since its 2026 pricing was competitive enough to change how we quoted higher-efficiency systems without turning every job into a hard upsell. The benefit wasn’t only the equipment cost. It also offered better availability, clearer warranty support, and a more consistent way to train the crews on what we were selling. It’s still a very unglamorous business compared with AI or SaaS, but the cash flow feels more real than it did at a lot of the startups I’ve seen. I still feel a little awkward explaining HVAC installs at networking events, which is probably just ego. Has anyone else left a cooler industry for a boring local service business and found that the economics were much better than expected?

Hi all,

Trying to find the furnace filter on this Goodman gas furnace(upflow install). Coil on top is a Goodman CAPF3030A6AA (mfg July 2007 per the serial). Can't spot an obvious filter slot. Photos attached,second one is a close-up of the top duct connection. Is the filter behindthe lower blower door on these, or should I be looking for a slot in thereturn duct?

https://imgur.com/a/Z9QV7UY

Thanks!

Hi everyone. Please bear with me on the amount of info but I feel I need to explain the circumstances of scenario happening.

So, I had a new York hvac system installed in late May of 2025. Air handler in attic with heat pump/condenser. I’m not knowledgeable enough to say more specifics. I have kept a yearly service care contract with the company that sold and installed it. I got a remainder to schedule my fall checkup which I did and got an appointment with a window of 8:00-10:00am. The morning of the appointment my daughter needed my wife’s car so I took my wife to work and was back home by 8:07am. The tech had been there for a couple minutes but he got out of van saying he was about to leave. I apologized and the appointment began.

When the guy came inside he wanted to go straight upstairs to the air handler. I thought that was odd because every tech I’ve ever had in my home has always lowered the temperature on thermostat before ever doing anything else. It was about 80+° already that morning if that helps explain what’s happening . Once he got up there, he didn’t come down for at least 25minutes and went straight out to his van and when he came back in I asked him what was happening. He said there was a bad heat strip and he needed a special tool to get to it, then he went back up for another 10-15minutes or so. Once he comes down he adjusts the thermostat and goes to the outside unit, checked and cleaned it. That was took about 30 or so minutes but that was the only normal part of the appointment. After that he comes back inside, reset the thermostat and said he would get the estimates for the heat strip and duct repair.

It took all I had not to get pissy about what he’s telling me since the system is under warranty and none of the other techs from the same company that were up there a few months prior or the year before has ever made any mention of something wrong with an air duct. Later that afternoon I get two estimates. The first is for $250 to replace the bad heat strip. The estimate acknowledges that the part is under warranty but $250 for labor. The 2nd estimate is to repair a damaged air duct for $500.

So this is where I’m out of my depth and I don’t know if I’m being irrational or if this guy was just pissed at me that he had to wait a few minutes. I went up in my attic that night and the only thing I see damaged on an air duct is one is pushed out of position by an inch or two and some of the insulation is freshly peeled away. No dust at the area and the edges where it’s torn are still shiny. This guy also never turned the heat on. Can you tell if a fairly new emergency heat strip is broken without turning on the heat? Why would he even go straight to that?

I don’t want to make an accusation if it is undeserved but my gut is telling me this is mostly BS. Could someone please tell me if I’m wrong about this? Should I call the office and ask for a different tech? Thank you to anyone that can share some insight with me.

Hi all, I was changing my filter today and found that the black cap fell out and as you can clearly see it was broken as if some pressure got released through that hole. There’s air coming out of it, (not high pressure ) whenever the AC turns on. Please help. Don’t know how long it has been running like that , I changed my filter 1 month ago and I believe it was fine then .

Thank you for your help in advance

We have a gas pack unit that is about 20 years old. Our regular HVAC company came by for the routine fall maintenance and the tech said this rusting meant the gas flame could no longer be contained, so he turned the gas off and recommended we replace the unit. As far as I know he didn't test the flame.

We have a home warranty (scam, I know) that I contact to see if they would cover any of the cost. The tech that came out said they don't service those kinds of units (always the case), but in his opinion the unit is fine. That the coils are all intact and that's what matters. That's such a different story than what I was expecting that I am questioning things now.

We'll end up getting a third opinion in a few days by default as the warranty company theoretically sends out a qualified tech to look at it seriously.

And so I turn to the internet for random opinions.

I am in a high rise condo with 3 identical minisplit air-conditioners. The bedroom AC (only) resonates when running and is making a a loud humming sound that makes sleep difficult. The noise disappears when I turn off the compressor.

i can feel the AC vibration at the compressor with my hand, but it is not noticeably different from the other two units that do not have this noise problem

Each AC compressor is sitting on two L shaped brackets with a 2x2x1/2 inch rubber pad as an isolator at each of the four mounting points. The L shaped brackets are attached to the exterior wall.

The 4 bolts that squeeze the mounting pads provide a direct mechanical connection between the AC mounting bracket and the L shaper bracket as the bolt head and nut are directly contacting the two metal frames. So I suspect the rubber pad is not effectively providing vibration isolation

How can I improve the noise situation from the bedroom AC? Each AC weighs 41 kg

There’s no compartment to take something out and dump it, just a bunch of water at the bottom of it and a little thing that water comes out of but it’s very slow, It’s an insignia portable ac.

Our home's 2005 single-stage Goodman heat pump had leaks in the air handler. Technician said it was the evaporation coil and some other part. He said vibration/rubbing caused the leaks. The system was old, so we just decided to buy a new one.

A local salesman gave us a quote for a single-stage American Standard Silver 14, which uses R-454B. Price is $8K installed.

The quote calls for re-using and flushing our existing refrigerant lines (pig/rubber bullet through the whole lineset) rather than replacing the lines. Salesman says that the 2005 copper lines have thicker walls than the 2026 lines. He says he can quote us new lines as an additional cost, but he claims the old lines are better. The company will do a nitrogen pressure test and deep vacuum test before charging the new system.

But my understanding is that R-454B operates at substantially higher pressures than the R-22 (true?). I also read that the old Goodman lines are a different width than the new American Standard.

Should I recycle the lines or should I get new lines?

We bought our new house in late spring and during the inspection there were a couple problems noted about the furnace vent. I honestly don’t know how they’re still alive because the vent through the attic was completely rusted to pieces. That portion was easy to fix, but I have questions about the portion in our crawl space. There is a single 4” pipe running roughly horizontal to a Y that splints one side vertically to the roof and another pipe that terminates with an open end a few feet away. I was planning on just replacing the Y with an elbow to the furnace. I have no clue what they were doing with the open pipe.

I’m having a new dual fuel heat pump + furnace system installed and want to have a fully modulating system for both the heat pump and the furnace. I was quoted the following Trane system:

- XC95m Furnace (TUHMC100ACV4VB)
- XV20i Heat Pump (5TWVOX4848A1000B)
- 5PXCC009AS3HAA Coil

They’re pairing this all up with a UX360/SC360 thermostat & controller.

My question is will this setup allow the furnace to be fully modulating with that thermostat pairing? They’re quoting a relay of some sort would need to pair with the furnace to allow it to communicate with that thermostat. Won’t that limit the furnace into 2 stage operation instead of modular? Are there any truly fully modulating dual fuel Trane systems if this one isn’t?

Thanks for your expertise!!

TLDR: we have a 20 year old electric furnace that struggles to heat a home. Looking for replacement recommendations and or how to avoid a $1,000 electric bill.

My husband and I bought a home in May 2026. Our home is equipped with a 20 something year old electric furnace and mini splits.

We have two vents that don’t blow any type of air, let alone warm air. We have a call into our home warranty and are expecting a technician early next week. When we moved into the home in spring, we did have our heat on and it ran for almost 2 days. It’s like it could never get up to the set temperature. We did figure out that the mini split that feeds into the ductwork/electric furnace is a “booster” unit. My husband did some type of balancing with setting the booster unit at one temp and the electric furnace at another but it still would struggle to hit 70.

We’re assuming that the technician is going to tell us a combination of: aged furnace, improper ductwork (our home was built by a contractor for him & his family) and dirty ductwork; we will have to get a new system…what do we replace it with? With the cost of electric only going to rise more with data centers and such, it seems wrong to put in an electric furnace.

The mini splits are: in our basement couch area and one in the basement that feeds into ductwork/electric furnace (if anyone knows that the hell kind of set up this is, please). We have 3 mini splits on our second floor in our primary bath, stairwell and 1 spare room. These have a date of install 2018 and do both aircon and heat.

Our home is rural and there is no gas line. We’d consider a pellet stove or alternative heating method recommendations. There is no wood burning fire place in the home or on the property. We had the mini splits mostly off this summer (horrible, hated it can’t wait until we can put central air back in) and our electric bill was around $250-$300 with a window unit running in our bedroom at night.

This is a replacement 80,000 btu Mr. Heater, with 4 inch metal pipe coming off the back. Previous heater had 8 inch pipe coming off it. Is it okay to run the new 4 inch straight into a cap on the 8 inch? The total length of the 8 inch pipe is about 4 feet from the roof to the end below the ceiling