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

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.

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.

Had a HVAC inspection set up through a company that had a rep at Lowe’s. He came out and said this may be a crack in the heat exchanger. The entire scenario was very high pressure and the reviews on the company are mostly fake 5 star reviews or 1 star reviews that the company engages in scammy practices. As far as I know he didn’t do any other pressure tests to determine leakage. Quoted me 4K to replace the heat exchanger (which may be under warranty - XV80 Trane from 2012 - and a failing leaky capacitor (which seemed legit).

Curious whether this is the right test and trying to get a second opinion about whether this could be legit.

Thanks in advance!!

Folks,

From an experienced residential, commercial, and industrial heating, ventilation, air conditioning, and refrigeration mechanic with multiple trade designations and credentials that allow for national and international mobility... quit asking about the safety of cracked heat exchangers. Most furnaces have negatively pressured heat exchangers, but we won't tell you to run it with a crack or a hole. It's a liability. Most furnaces have 25 year warranties on the heat exchangers. Call a reputable dealer. Get a second opinion.

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

I have a relatively new house, only about 4 years old, with a 4-ton Rheem single stage unit currently installed. The house is insulated with spray foam and has an outside air return on the system, but there's no damper installed. I live in central Texas, where the humidity is quite high. About two months ago, while inspecting the attic, I removed the panel from my unit and was shocked to find standing water inside and mold growing in the supply plenum.

I suspect the unit installed by the home builder wasn't set up properly. For some reason, it doesn't drain correctly. Although the condensate line isn't clogged and water does drain out, it seems like the cooling coil is leaking into the unit, and not all the water makes it to the drain. It even looks like water is splashing inside, and the cooling coil is already corroding.

I've had several AC companies inspect the system, and at this point, I just want to replace it with either a 2-stage unit or a variable capacity unit. My main concern is reducing the humidity in the house. Do you think the extra cost for the variable capacity unit would be worth it control the humidity?

I received two quotes—one for a Lennox Elite Series variable-speed unit and another for a two-stage Lennox Merit system. The company also plans to replace the supply and return plenum and install a humidity sensor and damper for the outside air.

Do these quotes seem reasonable?

Recently bought a two-story house with an HVAC system that’s approximately 20 years old. I’m really hoping I don’t have to replace the whole thing just yet. 😭

My thermostat is downstairs and set to 70°F.

Downstairs cools just fine, but upstairs feels closer to 80°F, especially in the master bedroom. You can just feel the difference in temp when walking downstairs from upstairs.

Here’s what I’ve noticed:
The entire upstairs is warmer than downstairs, but the master bedroom is by far the worst.

The master is huge, roughly the size of the other upstairs rooms combined.

There are two small vents high on the same wall in the master. Both blow air, but the airflow feels weak and not particularly cold.

I have a third vent near the floor that blows noticeably colder air than the wall vents but it’s not enough to cool the room.

The other upstairs bedrooms have their own vents and don’t get nearly as hot.

There’s a return vent near the upstairs staircase, and I recently changed the filter.

I also hear what sounds like a motor humming above my master bedroom ceiling, sometimes even when the AC doesn’t seem to be running.

I’ve tried switching the thermostat fan from AUTO to ON, but it didn’t seem to improve the upstairs airflow.

I’m wondering whether this could be a ductwork issue, airflow imbalance, or something else.

Before I call an HVAC company and potentially get told I need a whole new system, what should I check?

Is there anything I can reasonably troubleshoot myself?

I’m attaching pictures of the vents. Any advice is appreciated!

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.

Had my usual HVAC guys come out and look at our heater. Just tried turning it on for the first time and thermostat says it's on but no heat or even air is coming out. Keep in mind this unit is around 4 years old, purchased and installed by same company. Was told the board and heat sensor are out, and it's almost $2k for the labor to replace the parts, which are under warranty. How long does it take to replace these pieces? Does the quote seem excessive?

We missed having them come out to service/clean the unit 1 time since installation, and he indicated that was why it failed... though the unit is so new, I wonder if that's true.

It's in a scuttle attic, Lennox brand, and uses natural gas.

Can someone explain what these readings mean?

So, our maintenance is supposed to replace filters each year (?), but they’ve decided to never return again. I’m facing my fear of hvacs, because I know it needs to be changed (going on 1.5 years). We’ve already had people in our apartment building pass out from gas leaks due to the shabby installations during building renovation. They had to redo an entire 4 floors of duct work on one side of the building. I just need expert opinion and maybe some reassurance. Apparently, renovation was in 2021.

TLDR: It appears the filter is located on the bottom right side. It needs to be changed. I’m concerned about the quality of install and want to make sure I’m replacing/maintaining correctly.

Edit: I suppose I’m also asking how this install looks. Specifically the gas line and the space it is in.

Is ALL water supposed to flow through the PVC pipe and be shot out through the pump?

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 went to turn on my furnace for the first time since last winter and it's doing absolutely nothing. I have verified everything has power and have tried resetting it. Verified it has gas and the blower motor works. There's no error codes showing. But I did notice this brown part on one of the capacitors on the control board. Im pretty positive it's a bad control board but just wanted to get some more opinions before I order one. Model of the furnace is af80mpa125b5a

Thanks!

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

I wanted to have a spare capacitor ready for a Trane air conditioner. The label shows 45+5 uF +10/-5%. I see a lot of capacitors online with +/-5% or +/-6%.

How important is the +10% and can can I get by with +5%?

My wife and I just found out our baby has a low allergy with pet dander and was told to get an increased UV filtration system to add to our current HVAC system. I’m not sure what that means or even what to look at. Is there something we can do to our current HAVC that would help decrease our pet hair/dander? It’s not a severe allergy but does irritate a little bit so we wanna try everything we can before thinking of re homing our dog.

Curious of everyone’s thoughts here - I had a E298 error (no power) show up on my main floor thermostat with the AC not functioning.

Checked the feeder breaker - all good.
Checked the outside condenser wiring - seems good
Checked the condensate line and noticed water was dripping - seems good.

Opened the furnace panel and checked the control board 3A fuse and that was good. What I noticed was when reinserting the fuse the unit started back up then turned off. I looked and there was a bunch of tape on the panel switch holding it closed.

I pulled the tape off then pressed the button and the unit started working as expected. I didn’t want to touch anything until I removed feeder power so I put the panel back on and let it go overnight and it has been working ever since. Just now i received another E298 error for about 30 min then it recovered shortly after. I don’t see any error codes on the control board and am suspecting an intermittent access pane switch. Curious of everyone’s thoughts.

I help manage a small, older motel, and we’re trying to replace the loud wall units in a handful of rooms. I expected it to be a pretty straightforward swap, but the quote I got has me second-guessing the whole thing. The contractor walked me through a few packaged terminal heat pump options, which was helpful. The part I’m unsure about is the wall sleeves. He said some of the less expensive PTHP units might not fit the existing sleeves cleanly, so there could be extra labor in each room for sleeve modifications, sheet metal work, sealing, and drywall cleanup. I understand that not every unit will be a perfect slide-in replacement, and I’m not trying to cut corners if it could lead to water leaks or airflow problems later. At the same time, I don’t want to save a little on the equipment only to spend more cutting into walls, disturbing old finishes, and turning this into a much bigger project.

I live in a one-bedroom apartment with fairly high ceilings. There's a small hallway with a lower, drop-tile ceiling consisting of about 3–4 acoustic ceiling tiles and a return-air grille with a filter (pictured).

Directly above the ceiling is the AC unit, with roughly 1–2 feet of open space between the return grille and the unit. There's no visible ductwork connecting them, so I assume the ceiling cavity itself serves as the return-air plenum.

The system is incredibly loud when running. It's not so much the sound of rushing air, but a consistent, rhythmic "chug-chug-chug" or drumming sound that seems to come from the machinery.

Maintenance has inspected the unit for unrelated issues before, but I haven't specifically had the noise investigated.

I'm wondering whether there's a safe and effective way to reduce the noise without making major modifications, since I'm renting.

Specifically, could I place some kind of acoustic insulation or sound-dampening material above the surrounding ceiling tiles, without obstructing the return grille, filter, or airflow? Or would that be ineffective or unsafe given that the cavity is used for return air?

I'm also curious whether this kind of rhythmic noise is typical of an air handler or might indicate a vibration/mechanical issue worth having maintenance investigate.

Any advice appreciated!

My mothers house often loses power in the winter, and I noticed that her propane furnace just plugs into a 120v socket, presumably to light the gas and run the fan.

I thought about getting one of those portable lithium ion batteries to plug her furnace into when her power goes out, but it occurs to me that if the thermostat is off, the furnace wouldn’t kick on would it?

So, do thermostats usually connect to the furnace and fan directly, or are they just wired on the circuit in the room they are in with a separate wire to communicate to the furnace?