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.

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.

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.

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.

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 (now dead) used R-22. It 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 (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

Just had to share the rabbit hole I traveled down to install an Amazon (Honeywell) thermostat. I had a weird setup for my old thermostat, see below. I also had only four wires going to and from the AC unit to the thermostat. So I bought a C-wire adapter to go with my amazon thermostat and connected things according to the basic configuration. Unfortunately, my weird setup with a basic configuration produced hot air instead of cold. The AC unit pumped heat out and made it even hotter--in Florida, that is "no bueno!"

In desperation, I googled and gemini-ed and perplexity-ed like crazy. In the end one of the links I clicked on led me to JustAnswer (https://www.justanswer.com/) where I was connected to an actual person: Andre HVAC Tech. He was patient, calm and walked me through the multiple screens and checkboxes to connect my AC unit to the Amazon Thermostat.

In the end, I just needed to swap a couple of wires and then reset the unit as if I was installing it for the first time. The key was pretending I was going through the whole system setup (wire, installing the wall plate, etc) so that I was able to change the wiring to what Andre diagnosed as correct for my system. Note, you CANNOT change this wiring unless you start from the beginning and go through all the steps. Obviously other systems will be different, but here are the pics of my situation and final functioning arrangement.

I hope my troubles will help you get to a quick solution for your problem if you're experiencing similar frustrations. Stay Cool!!!

Have a C9MPD100J20A2 that always gives me problems. Yes I know it’s time to replace but I like to keep the guy running!

Usually it’s a lockout due to a flame roll out. Then it’s an inducer motor. This year it’s something else.

I found the unit locked out. Reset everything, unit fires up but noticed the blower motor didn’t seem to be working.

The motor spins easily, the capacitor isn’t bulging, etc. took it out and cleaned it. Put it back in and got it to go with a little fooling around.

Today it’s not working again. So I think it’s the capacitor, try a new one. Nothing. Think it’s the motor, replace with a Climatetec (think I have it wired right) nothing.

I hear the relay click and it seems like it’s going to turn but doesn’t.

Could it be the transformer? I know everyone is going to say hook up a meter and see if I’m getting 24V from it, just seems weird.

Pictures attached. Any ideas?

I have an older Rheem NG furnace. In 2021 I went through it and replaced and saved several working parts for preventative maintenance. In doing so I saw that a tech had installed a silicone nitride universal Glowfly Q4200U igniter se real years prior. I replaced it with a Honeywell silicon carbide igniter that was a direct replacement for the original.

In reading about igniters recently, I now understand that the silicone nitride last much longer than the original silicon carbide.

The Glowfly is shorter than the factory model and but was working fine when I removed it several years ago. Looking at the specs it replaces lots of igniters but only one Rheem which is not my model.

If the Glowfly was working fine should I buy a new one and just use that? There are less common universal igniters like the Supco SSN 3000 that are also silicon nitrite that I could also get.

The igniter mounts so it’s above the burner pointed toward the flame tip at a 45 degree angle. The Glowfly is about 3/8” shorter than the factory.

What’s folks experience with the Glowfly?

I have a 1980s built bungalow in Ontario Canada. My furnace is 15 years old and the ac is built in 1990. I haven’t had any issue with the ac but spent about 1500 on the furnace in the last 4 years. I got quoted 125 a month total for a 7 year rental term for both units. This is a rental property and at my own property i bought out my units. Im leaning towards renting just so theres no head ache. The rental does cost about 2,000 more over the 7 years. Im a little confused and wanted to hear some more opinions. Thanks for any replies!

I'm a very skilled tradesman in industrial maintenance and am good with tools.

My biggest concern is dealing with the ac coils. I have the coils in the AC unit replaced 5 years ago. The furnace is 25 years old

System not cooling.

Airflow is good with a clean filter, strong airflow coming out of the vents. Small copper line isn't warm like it's supposed to be. Large copper line isn't cold like it's supposed to be. Fan on condenser unit is running.

I'm guessing something is up with the compressor. Either that or the capacitor is shot. They have one capacitor for the fan and one for the compressor. And of course it happens just as the system no longer has it's 10 year warranty.

I tried turning everything off for about an hour because I had a similar situation in the past where the power randomly fluctuated and the AC stopped cooling I guess because the compressor overheated or some odd stuff like that?

Edit: And the moment I posted this and turned the system back on, it randomly started cooling again. Any ideas why it did this? Is this a sign that my compressor is on its way out?

Edit 2: And it stopped cooling again.

Can someone tell me if this is normal? The unit is unusually loud and seems unstable.

https://www.youtube.com/shorts/sqXAJxxkB3w