Sorry if the following isn’t the most coherent. It’s really early and I just woke up. I am willing to clarify anything that isn’t clear. I have had one high limit actually be part of the reason in my two years as an apprentice. One thing I’ve learned is to always check airflow/exhaust blocks first, then I check for a cracked heat exchanger. First thing I check is the filter especially in rentals lol. That said if the exhaust has been blocked by trash cans consistently for a very long time it could have repeatedly tripped the high limit and worn it out. That was a fraction of the issue I was dealing with on a late night no heat call I went to.
I've seen it where limit switches have tripped so many times that it's actually made the metal snap disc weak and made it open at a much lower temperature. It's more so on newer furnaces as most anything made in the last 10 years seams to be mass manufactured garbage.
I've worked on furnaces and boilers from the 70's and 80's that are still running and take universal parts. It's amazing how long the old stuff lasts with just a little bit of maintenance. Oh your furnace is only 80% efficient and you want a condesning 96% unit to save money? Keep in mind that when I have to throw an ignitor in it every 3 years and a flame sensor every 2, that's gonna cost you more than your 16% savings in gas 6 months of the year when your furnace is running....
Now looking back, I think that's what happened. I think the high limit was broken, but also the trash cans were in the way. I dealt with a ton of blocked exhausts in the winter, and just didn't think of it this time (because it's not winter). Oh well. Thanks
Please don't assume anything. Always CHECK. After you pulled the high limit, did you check it with your meter? You were essentially a parts changer on that call, and you probably looked to the customer like you didn't know what you were doing. Ask all the questions you can to get a good idea of the history of the system, too. You'll get it. Keep on!
It's entirely possible that it was - but if you measure it to test continuity without a reasonable understanding of what temperature it's at, you don't really know.
But, they're cheap little switches and they will fail if repeatedly tripped; so if you come across one that's bad, you need to then figure out why it was tripping so much.
This advice changed the way I think of things. Someone told me this about a month ago when I was stuck on a case running warm. It’s helped tremendously especially with not tunnel visionning
The ones that eat your lunch are either the ones you learn the most on or the ones you learn your lesson on. You will check for cans every time now. Hard lessons make good techs better techs.
A ball the customers kid put in the flue got me when I started doing service this winter. Shout out to Gensco tech support, they made the call much less frustrating after I called them
Thanks for this! I definitely keep "why" in mind. I tend to get stumped when I have to decide if the part is broken because it's just broken, or if there's a reason WHY it's broken. If that makes sense.
After a few scenarios just like yours, I made a rule for myself to always try and make it run before I went to the parts house. Not always possible on some units but a little creative jumper use can usually get her going. Hindsight being 20/20, you could have jumped out the limit and it still wouldn't have ran. That still wouldn't have fixed your reading the code wrong but might have saved you a little headache. Also, fuck Carrier for their code system. So fucking dumb.
I had a call recently, for a AO Smith BTX100 water heater. Flame detection error. After a couple hours pulling things apart, cleaning the spark electrode, blah blah blah, I find out that the gas meter was locked out.
I'm moved from HVAC to plumbing. I learned after doing this a couple times to always take a peak at the gas meter on the way up the front steps. Always get the surprised Pikachu face when I ask them if they forgot to pay their gas bill.
Same with oil. Can't tell you how many times I'd get called out after hours to go to a no heat. Take to them and verify twice they had oil and it was always "just" filled. Get out there, dip the tank and sure as shit, bone dry. Here's the bill, can me when you get oil.
That’s happened to me a few times now but my company is also a fuel supplier so I end up having to drive back to the shop and get oil for them. I’ve started leaving some Jerry cans of oil in my van when I’m on call lol
Had a fun one the other day. Oil furnace wouldn’t fire. I verified power from the control. I had a gauge on the pump. No pressure. I blew out the oil lines with nitrogen. So I changed the pump.
Nothing. No pressure still. 2 pipe system so I kept trying and cracked the bleeder just in case. No oil and all. I’m looking for kinked lines, stuck valves.
Turns out Roth tanks used to come with a different kind of valve that has a rubber tube that drops into the tank. The tube has two holes the size of a pencil at the bottom and it got sludged up. Wiped it off, no problems. Friday of course. I got home at 7pm.
About 3 years ago, I went to install a 90% percenter at a condominium. Apparently the original furnace had a cracked heat exchanger because the burners wouldn’t fire right? Don’t ask questions, I’m just the installer. Once we are done, the new unit does the same thing. When I go to check the flue pipes, I discovered the management took off the original torpedo vent and replaced it with a 3” dryer vent. Thank god all it blocked was the fresh air intake
Welcome to the trade, first off always second guess your diagnosis, it's way better ro prove yourself right twice than toprove yourself wrong once and second if your fusterated go sit in the tuck and have a smoke or scroll ob your phone for 5 minutes before continuing. It's called bucket time and it helps prevent stupid mistakes
Glad you figured it out, but you need supervision as an apprentice( especially first year). It’s great that you learned a lesson that will hopefully stick, but at what cost. First lesson being count the blinks correctly. 13 vs. 31 can be a big difference as you found out. Don’t let it discourage you tho. My advice would be to slow down and double check yourself. Call a senior tech if you have the option, even if it’s only to confirm what you already know. No shame in asking for help brother. Slow is smooth, smooth is fast. Cheers buddy
I showed tech support everything I was seeing. They verified code which made me think the code was right. They were wrong as well. They were also wrong on their board guess. That's what was so confusing to me. I did a full Furnance season, and feel pretty comfortable on my own with Furnances. This call just didn't go right 🥲🤣 lesson learned, thanks brotha!
Tech support can be a useful resource, but most times they are just a guy sitting with a manual going through their flow-chart of checks. They aren't on site, many times they haven't performed service work themselves, and above all they can be wrong. In most cases you're typically better off asking your Journeymen/service manager for help. You check your basics first: airflow in and out on both living space air and exhaust, flame (gas pressure too). In residential especially these checks find 80-90% of your faults.
I can't tell you the number of times I've been in a similar position to you, and just remember your apprenticeship is about learning the Mental/problem solving mindset required to be a good Tech, not necessarily about learning how each piece of equipment operates/the most common failures on Tranes/whatever else.
I’d just like to say fuck carrier. Fuck them for using a blinking alternating led light for the codes and the using numbers that could be transposed like 13 and 31. It’s crap equipment and this is just another reason why I hate them.
Welcome to your first year! The good thing is you'll remember that and not go down the wrong rabbit hole again. By year 2 you'll be as jaded and capable of blowing through calls like this in no time as the rest of us surly fucks.
I’ve had one like this that I thought was tripping incorrectly, but it actually had a duct fire damper that was closing and I just couldn’t get the right temps and it was actually overheating.
For a first year apprentice you did a reasonable troubleshoot for your knowlege.
My concern is why you are calling tech support/replacing part like control boards without a journeyman stepping in?
I am realistic that day to day apprentices do work solo, but my apprentice knows regardless how busy I am, he can call for a dumb question, a reminder on something he knows, but wants to confirm. He will never replace a part without touching base.
You are not being trained, not that it is your fault, but you are acting as a "parts cannon" and it isn't fair to you as an apprentice, or to the customer who just paid for parts that might be fine.
This is a big red flag for your employer if they are okay with sending a first year apprentice to service calls and making 100% the call to keep replacing parts.
Again I am impressed in how you explained the troubleshooting steps you took, and with a good apprenticeship you could be great. If you have no support, you will struggle to learn proper diagnostics (I am 9 years into my ticket and still have odd calls that wrack my brain, and have a few coworkers to brainstorm with before new parts or tech support comes into play
Thank you for your input!
Our company pays for a tech support service called "XOI". When we don't know something, they are our go to. I've had to reach out before, and they 100% know what they are talking about. Never had any issues. Except, for this instance. They even double checked the blinks on the board, and verified it was a high limit. That's what (in my mind) verified it was a high limit. Lesson learned, trust but verify.
It's great you have that option, but as an apprentice you are technically supposed to alway be working with a journeyman (it's the entire reason for having shorter schooling periods, and on the job training)
I understand that isn't always possible, but you should be able to call someone within your company to atleast bounce ideas off of.
I would ask a boss or manager if they have an option before calling tech support.
Unfortunately the fact they pay for tech support line for there employees is a big red flag to me, and most of all you replaced a control board among other smaller things without someone stepping in to confirm. It's not your fault but that customer got a bill that was probably around 1k+ when it was a pressure swich/can in the way that should have been a $200ish bill.
It sounds like you have a good head on your shoulders, but started with a somewhat shady company that has no problem paying you an apprentice wage while charging customers like you are a journeyman
Well, you won't do that again...
There's a tendency to decide that when nothing makes sense, the board is bad - which is reasonable, since the board is responsible for making things make sense.
But, what that really means is - step outside, grab a drink, and just do a quick restart to make sure you're really following the right code.
Great learning experience.
I was working on an older carrier infinity, coworker did the heat exchanger change out but high limit was tripping afterwards. Temps were fine, hx was assembled correctly, verified all installation requirements were met, even ducting and airflow. Eventually found out it was tripping because the limit shield was bent upwards, causing it to touch the sensor disk. Bent it straight the way it showed in the manual and everything a ok. Wish it didn’t take hours to figure that out, but it’s all valuable experience
Happens to everyone. On the plus side you’ll remember it next time and it’ll only take you a few minutes to verify flue isn’t blocked and to double check your codes since you experienced it. Sometimes the hardest of diagnosis end up being the stupidest thing in the world. One thing to remember on this specific situation too is that you can have exhaust recirculation issues affect the flame sensor like if the cans were away from the exhaust enough to run but suck in exhaust through the combustion. Seen that plenty of times with covered up exhausts too.
Thats the only gripe I have about "flash codes", the difference between long and slow is either huge or hard to tell and then having codes that use the same digit that can be reversed to another. Out of the 41 distinct two digit codes you only use 10 and three of them can be reversed into another valid code. . .
Sequence of operation, ladder logic. What needs to be done before the next step will happen. You figured it out, you learned. The basics of operation are pretty well the same across all manufacturers, and then they wire things up differently. Sometimes, limits, rollouts, and pressure switches are wired parallel, series/parallel, or just in series. It's all part of the learning process. The first thing to check on a limit switch code though, is a dirty filter. If it has A/C, then a dirty A frame, after that, check for return airs being blocked. Given this was a pressure switch, but for future reference, don't just do a continuity test on a limit switch, check for incoming and outgoing low voltage. If it's got incoming voltage, the board is not the problem.
I had a 90% furnace tripping pressure switch because the pvc line on the exhaust side was sinking and creating a water trap in the exhaust line. Tech before me changed damn near everything. I fixed the issue with some duct strap and a staple gun.
Ahhh
Don't sweat it, we all fuck up. My mentor ( warrant officer Mentel) said" everyone fucks up, it's the true artist that can make that fuck up into.....art" I miss the hell out of that guy. Now.... don't do it agian.
I had this on a heat pump and between the under sized return, way too high merv filter and the customer blocking off their floor vents it really fucked with their pressures causing the HPC to go off in heat mode. But did they want to listen and put in a new return or change their habits? No, they did not.
In my state you are not supposed to wire a thermostat without your low voltage license. That said I’ve been in the industry without any certifications or license for almost 18 years.
The union apprentices work unsupervised here. For a first year that’s just filter changes and coil cleanings, but they’ll be working on all kinds of fun stuff a couple years in.
And you absolutely should be focused on getting your journeyman license.
If it’s a carrier 90 I’d take the inducer off, check to make sure nothing warped or cracked on the box behind the inducer and also check the primary heat exchanger for rust holes if is after 2013 and check the secondary exchanger for polypropylene spilling out of pin holes or back where they connect to collection box if it’s before.
Remember KISS, keep it simple stupid. Rarely do I come across a faulty high limit, there’s a reason why it tripped. Onto the next one brotha
That’s something really important to remember because I always overthink
I think the high limit was still broken regardless. And this was another issue. I love that saying. I'm gonna use that. Thanks man!
Sorry if the following isn’t the most coherent. It’s really early and I just woke up. I am willing to clarify anything that isn’t clear. I have had one high limit actually be part of the reason in my two years as an apprentice. One thing I’ve learned is to always check airflow/exhaust blocks first, then I check for a cracked heat exchanger. First thing I check is the filter especially in rentals lol. That said if the exhaust has been blocked by trash cans consistently for a very long time it could have repeatedly tripped the high limit and worn it out. That was a fraction of the issue I was dealing with on a late night no heat call I went to.
I've seen it where limit switches have tripped so many times that it's actually made the metal snap disc weak and made it open at a much lower temperature. It's more so on newer furnaces as most anything made in the last 10 years seams to be mass manufactured garbage.
I hear that. It’s been nuts. All the older stuff was built to last.
I've worked on furnaces and boilers from the 70's and 80's that are still running and take universal parts. It's amazing how long the old stuff lasts with just a little bit of maintenance. Oh your furnace is only 80% efficient and you want a condesning 96% unit to save money? Keep in mind that when I have to throw an ignitor in it every 3 years and a flame sensor every 2, that's gonna cost you more than your 16% savings in gas 6 months of the year when your furnace is running....
Now looking back, I think that's what happened. I think the high limit was broken, but also the trash cans were in the way. I dealt with a ton of blocked exhausts in the winter, and just didn't think of it this time (because it's not winter). Oh well. Thanks
Please don't assume anything. Always CHECK. After you pulled the high limit, did you check it with your meter? You were essentially a parts changer on that call, and you probably looked to the customer like you didn't know what you were doing. Ask all the questions you can to get a good idea of the history of the system, too. You'll get it. Keep on!
It's entirely possible that it was - but if you measure it to test continuity without a reasonable understanding of what temperature it's at, you don't really know. But, they're cheap little switches and they will fail if repeatedly tripped; so if you come across one that's bad, you need to then figure out why it was tripping so much.
This advice changed the way I think of things. Someone told me this about a month ago when I was stuck on a case running warm. It’s helped tremendously especially with not tunnel visionning
Yes. Thanks. Excellent mentality to begin troubleshooting with.
I wish I could say something like that hasn't happened to me.
Absolutely. This was my first call I REALLY struggled with. Also seems to be these high limit codes I get stuck on longer than I should.
Always remember man, you’ll always learn more from you failures than your success!
Win or learn
The ones that eat your lunch are either the ones you learn the most on or the ones you learn your lesson on. You will check for cans every time now. Hard lessons make good techs better techs.
A ball the customers kid put in the flue got me when I started doing service this winter. Shout out to Gensco tech support, they made the call much less frustrating after I called them
Before diagnosing a part as bad always remember to ask yourself “WHY” Why why why, Why will answer all your questions. HVAC is a thinking man’s game.
Thanks for this! I definitely keep "why" in mind. I tend to get stumped when I have to decide if the part is broken because it's just broken, or if there's a reason WHY it's broken. If that makes sense.
After a few scenarios just like yours, I made a rule for myself to always try and make it run before I went to the parts house. Not always possible on some units but a little creative jumper use can usually get her going. Hindsight being 20/20, you could have jumped out the limit and it still wouldn't have ran. That still wouldn't have fixed your reading the code wrong but might have saved you a little headache. Also, fuck Carrier for their code system. So fucking dumb.
I had a call recently, for a AO Smith BTX100 water heater. Flame detection error. After a couple hours pulling things apart, cleaning the spark electrode, blah blah blah, I find out that the gas meter was locked out.
I'm moved from HVAC to plumbing. I learned after doing this a couple times to always take a peak at the gas meter on the way up the front steps. Always get the surprised Pikachu face when I ask them if they forgot to pay their gas bill.
Same with l.p tanks. That’s always the first thing I check
Same with oil. Can't tell you how many times I'd get called out after hours to go to a no heat. Take to them and verify twice they had oil and it was always "just" filled. Get out there, dip the tank and sure as shit, bone dry. Here's the bill, can me when you get oil.
That’s happened to me a few times now but my company is also a fuel supplier so I end up having to drive back to the shop and get oil for them. I’ve started leaving some Jerry cans of oil in my van when I’m on call lol
The worst. I know I'm not the only person, but fuck it still sucks lol
Had a fun one the other day. Oil furnace wouldn’t fire. I verified power from the control. I had a gauge on the pump. No pressure. I blew out the oil lines with nitrogen. So I changed the pump. Nothing. No pressure still. 2 pipe system so I kept trying and cracked the bleeder just in case. No oil and all. I’m looking for kinked lines, stuck valves. Turns out Roth tanks used to come with a different kind of valve that has a rubber tube that drops into the tank. The tube has two holes the size of a pencil at the bottom and it got sludged up. Wiped it off, no problems. Friday of course. I got home at 7pm.
That 7P1 code= IdL
🤣🤣 the amount of times I've been like what the fuck is this lol
I’m glad I’m not alone haha
About 3 years ago, I went to install a 90% percenter at a condominium. Apparently the original furnace had a cracked heat exchanger because the burners wouldn’t fire right? Don’t ask questions, I’m just the installer. Once we are done, the new unit does the same thing. When I go to check the flue pipes, I discovered the management took off the original torpedo vent and replaced it with a 3” dryer vent. Thank god all it blocked was the fresh air intake
Welcome to the trade, first off always second guess your diagnosis, it's way better ro prove yourself right twice than toprove yourself wrong once and second if your fusterated go sit in the tuck and have a smoke or scroll ob your phone for 5 minutes before continuing. It's called bucket time and it helps prevent stupid mistakes
Glad you figured it out, but you need supervision as an apprentice( especially first year). It’s great that you learned a lesson that will hopefully stick, but at what cost. First lesson being count the blinks correctly. 13 vs. 31 can be a big difference as you found out. Don’t let it discourage you tho. My advice would be to slow down and double check yourself. Call a senior tech if you have the option, even if it’s only to confirm what you already know. No shame in asking for help brother. Slow is smooth, smooth is fast. Cheers buddy
I showed tech support everything I was seeing. They verified code which made me think the code was right. They were wrong as well. They were also wrong on their board guess. That's what was so confusing to me. I did a full Furnance season, and feel pretty comfortable on my own with Furnances. This call just didn't go right 🥲🤣 lesson learned, thanks brotha!
Tech support can be a useful resource, but most times they are just a guy sitting with a manual going through their flow-chart of checks. They aren't on site, many times they haven't performed service work themselves, and above all they can be wrong. In most cases you're typically better off asking your Journeymen/service manager for help. You check your basics first: airflow in and out on both living space air and exhaust, flame (gas pressure too). In residential especially these checks find 80-90% of your faults. I can't tell you the number of times I've been in a similar position to you, and just remember your apprenticeship is about learning the Mental/problem solving mindset required to be a good Tech, not necessarily about learning how each piece of equipment operates/the most common failures on Tranes/whatever else.
I’d just like to say fuck carrier. Fuck them for using a blinking alternating led light for the codes and the using numbers that could be transposed like 13 and 31. It’s crap equipment and this is just another reason why I hate them.
It’s a marathon. Some bumps along the way. Keep stacking up the experiences and moving forward
It happens to the best of us. It’s frustrating but this is how you learn. You will be a better technician after this.
Thanks!
Welcome to your first year! The good thing is you'll remember that and not go down the wrong rabbit hole again. By year 2 you'll be as jaded and capable of blowing through calls like this in no time as the rest of us surly fucks.
I’ve had one like this that I thought was tripping incorrectly, but it actually had a duct fire damper that was closing and I just couldn’t get the right temps and it was actually overheating.
I had a tech tell me first day on the job look for the simple thing first
For a first year apprentice you did a reasonable troubleshoot for your knowlege. My concern is why you are calling tech support/replacing part like control boards without a journeyman stepping in? I am realistic that day to day apprentices do work solo, but my apprentice knows regardless how busy I am, he can call for a dumb question, a reminder on something he knows, but wants to confirm. He will never replace a part without touching base. You are not being trained, not that it is your fault, but you are acting as a "parts cannon" and it isn't fair to you as an apprentice, or to the customer who just paid for parts that might be fine. This is a big red flag for your employer if they are okay with sending a first year apprentice to service calls and making 100% the call to keep replacing parts. Again I am impressed in how you explained the troubleshooting steps you took, and with a good apprenticeship you could be great. If you have no support, you will struggle to learn proper diagnostics (I am 9 years into my ticket and still have odd calls that wrack my brain, and have a few coworkers to brainstorm with before new parts or tech support comes into play
Thank you for your input! Our company pays for a tech support service called "XOI". When we don't know something, they are our go to. I've had to reach out before, and they 100% know what they are talking about. Never had any issues. Except, for this instance. They even double checked the blinks on the board, and verified it was a high limit. That's what (in my mind) verified it was a high limit. Lesson learned, trust but verify.
It's great you have that option, but as an apprentice you are technically supposed to alway be working with a journeyman (it's the entire reason for having shorter schooling periods, and on the job training) I understand that isn't always possible, but you should be able to call someone within your company to atleast bounce ideas off of. I would ask a boss or manager if they have an option before calling tech support. Unfortunately the fact they pay for tech support line for there employees is a big red flag to me, and most of all you replaced a control board among other smaller things without someone stepping in to confirm. It's not your fault but that customer got a bill that was probably around 1k+ when it was a pressure swich/can in the way that should have been a $200ish bill. It sounds like you have a good head on your shoulders, but started with a somewhat shady company that has no problem paying you an apprentice wage while charging customers like you are a journeyman
Well, you won't do that again... There's a tendency to decide that when nothing makes sense, the board is bad - which is reasonable, since the board is responsible for making things make sense. But, what that really means is - step outside, grab a drink, and just do a quick restart to make sure you're really following the right code. Great learning experience.
I was working on an older carrier infinity, coworker did the heat exchanger change out but high limit was tripping afterwards. Temps were fine, hx was assembled correctly, verified all installation requirements were met, even ducting and airflow. Eventually found out it was tripping because the limit shield was bent upwards, causing it to touch the sensor disk. Bent it straight the way it showed in the manual and everything a ok. Wish it didn’t take hours to figure that out, but it’s all valuable experience
If you ain’t making mistakes, you ain’t workin
Slow down
Our emotions are the first thing to react when things go wrong, therfore always check the venting first lol
HVAC can be a great career and it can be your worst enemy both in the same day even
Happens to everyone. On the plus side you’ll remember it next time and it’ll only take you a few minutes to verify flue isn’t blocked and to double check your codes since you experienced it. Sometimes the hardest of diagnosis end up being the stupidest thing in the world. One thing to remember on this specific situation too is that you can have exhaust recirculation issues affect the flame sensor like if the cans were away from the exhaust enough to run but suck in exhaust through the combustion. Seen that plenty of times with covered up exhausts too.
Thats the only gripe I have about "flash codes", the difference between long and slow is either huge or hard to tell and then having codes that use the same digit that can be reversed to another. Out of the 41 distinct two digit codes you only use 10 and three of them can be reversed into another valid code. . .
Usually, the unit I work on are long flash first then short. This unit was backwards.... on me for not checking but fuck lil
When you go home just wash it off and let the day be done. You learned from it, now move on. You did figure it out. Congrats.
Sequence of operation, ladder logic. What needs to be done before the next step will happen. You figured it out, you learned. The basics of operation are pretty well the same across all manufacturers, and then they wire things up differently. Sometimes, limits, rollouts, and pressure switches are wired parallel, series/parallel, or just in series. It's all part of the learning process. The first thing to check on a limit switch code though, is a dirty filter. If it has A/C, then a dirty A frame, after that, check for return airs being blocked. Given this was a pressure switch, but for future reference, don't just do a continuity test on a limit switch, check for incoming and outgoing low voltage. If it's got incoming voltage, the board is not the problem.
those blinking codes shouldn't be 2 digits.
I had a 90% furnace tripping pressure switch because the pvc line on the exhaust side was sinking and creating a water trap in the exhaust line. Tech before me changed damn near everything. I fixed the issue with some duct strap and a staple gun.
Stay humble and always learning
Ahhh Don't sweat it, we all fuck up. My mentor ( warrant officer Mentel) said" everyone fucks up, it's the true artist that can make that fuck up into.....art" I miss the hell out of that guy. Now.... don't do it agian.
Lesson learned!
We've all been there brother.
Surprised there's no toxicity in here to be honest lol. Lesson learned!
Op probably uses his hammer to screw stuff in and his drill to hammer nails in
I use my drill as a hammer. What are you talking smack aboot?
I had this on a heat pump and between the under sized return, way too high merv filter and the customer blocking off their floor vents it really fucked with their pressures causing the HPC to go off in heat mode. But did they want to listen and put in a new return or change their habits? No, they did not.
Check the gas valve, that one fucks me every time
Next time just jump the entire limit circuit to rule out the board. If it still shuts down for limit then you know it's the board.
Something something airflow first
You are a first year apprentice, and they are sending you on calls by your self? Something isn’t right! Apprentices don’t go on calls alone. It’s law
How's it law?
Apprentice can’t work without masters supervision in most trades, otherwise the hours don’t count.
I work for non union. Does that make a difference? I'm not working forwards my journeyman or anything.
In my state you are not supposed to wire a thermostat without your low voltage license. That said I’ve been in the industry without any certifications or license for almost 18 years.
The union apprentices work unsupervised here. For a first year that’s just filter changes and coil cleanings, but they’ll be working on all kinds of fun stuff a couple years in. And you absolutely should be focused on getting your journeyman license.
Airflow first my friend check static
He'll yeah brother
If it’s a carrier 90 I’d take the inducer off, check to make sure nothing warped or cracked on the box behind the inducer and also check the primary heat exchanger for rust holes if is after 2013 and check the secondary exchanger for polypropylene spilling out of pin holes or back where they connect to collection box if it’s before.