I learned from someone that pulling out outdoor fan during whole system is running, head pressure should go up , low pressure stays same level for awhile, Txv is good. If low pressure goes up at meantime, telling Txv is bad. Thank you for sharing your knowledge with us.
There must be a better way to check if the TXV is bad. The sub-cool was good telling that that the refrigerant is good. The airflow was good. Dirty condenser and filter would sometimes do that. But that I guess was good leaving the TXV faulty. It’s unable to let the proper amount of refrigerant into the evaporator. I am still in school for air conditioning and refrigeration so I am no means an expert but my job as a watch engineer is also plumbing and AC. When there is a low refrigerant or leak or bad TXV, I let my chief engineer whom has been doing that for 40 years take care of that. I take care of everything else so I am learning and watching those videos helps me a lot. Keep with the good work.
Low air flow would of made your super heat low,not high.It has the correct amount of refrigerant,look at that sub cool.Let’s see good on charge but superheat is off....What controls superheat?TXV check why it is underfeeding. Even more so low air flow would of made your delta t higher .
Hey man I appreciate how to really explain and how you explain in detail what you do. New tech here and actually learning about txv has been a bit challenging
Definitely TXV it’s slightly restricted, that’s why you have a high subcool when you started to add more refrigerant you have more liquid outside on the liquid line because it can’t get through that TXV kind of backed up. Suctions low like you said and your superheat is slightly high. It’s pretty much starving the evaporator and stimulating sort of like a low on charge that’s also why your delta T is low, not enough refrigerant going through the evaporator.
good video, there was a better way of testing for the txv being bad. without wasting refrigerant. block the condenser and the SH shouldnt change if it does, then you got yourself a bad txv. very informative video. im a new subscriber. keep the videos coming.
Awesome video! I know I’m super late to the party but I agree the TXV is out of range and should be replaced. The only extra step I would have added is shutting down the system and watching the TXV equalize. Sometimes that will be a dead giveaway.
Can you further explain about equalization? Would it not equalize? I’m asking because I had one, and after I shut the system down for a bit I noticed there wasn’t equalization or it didn’t happen as quick as I thought it should. Thanks for the response
@@SickaMorStylewhen you shut down the system, the txv senses suction temp, so the suction line warming up will cause txv to open up hints equalizing the pressures
You can do both hot or cold. Hot water would open txv to allow more refergerant in causing lower super heat, cold water would close valve causing superheat to raise
You could also as a precaution check the temperature across your filter dryer. Looks like a small liquid restriction, possibly from someone not purging the system and not brazing with nitrogen causing oxidization that could clog the txv screen, or the filter dryer. Sensing bulb may also not be secured properly or insulated. That said looks like your on the right track.
Note for the official record, you should’ve taken the bulb off in the first place of the TV and put it in a warm bucket of water before adding refrigerant. That would be the simple solution to the problem as well is a timesaver as well.
I’ve been seeing that lately as a check to make sure it’s not stuck open or whatever but doing this could it unstick it if it is partially blocked or just sticking?
We got a smart guy. Come on. We all think different. Ian’s it’s fine. Just because you saw that fast. All you can see is his screen. He was probably looking at other things. We always want to show that we are smart. Instagram humble ourselves and maybe even say I learned something today. Or at least give a compliment or great video.
I thought your supposed to put the sensing bulb in something hot so we can forced open the valve not ice water. I believe that closes the valve more. just checking.
You did good on this. I’m sure people will learn proper techniques from this video. I’ll be a new subscriber. I have videos as well you can learn from.
I would've checked airflow first before checking the charge, but that's just me. After all, EAR. E-lectrical A-ir flow R-efrigerant Great video otherwise. Keep 'em coming. 😏
I can see a huge problem on that furnace. The return should came in from both sides of the furnace. With that filter as dirty as it is raises static pressure and lowers CFM and can simulate a bad TXV.
Thanks for showing the numbers. Most youtubers don't or will show on a tiny cellphone. Dang, you got nice tools for the job. Maybe some day I will too. What do you think of putting the txv bulb in cold water then hot to see if its adjusting.
Piston should be charged by superheat . Txv by subcooling. Your delta T is 11 it tells you right away you have a system restriction. Filter dryer, or system contamination or . You must check first if all your mechanic components are clean then see if you have a piston or TXV . You cant charge or measure a TXV system based on superheat it have to be on subcooling.
You know….. This TXV n 410A Have caused more problems n forced homeowners to spend more money…. Pain and frustration. Of course it keeps field technicians busy…but not all technicians have adequate knowledge of how to address n fix it…. Specially in sunbelt area it’s not easy to work in hot 100+ attic. To a point it’s not worth it!
If you want to know if your txv is working, you need to change conditions. The easiest way is to disconnect the outdoor condenser fan, a properly working txv will keep superheat and suction pressure the same or just a little higher. But if it begins to climb then txv needs replacement.
Just had this problem literally today and same results normal to high subcool high superheat low delta T did a bulb test with the txv and turns out bulb had lost its charge
First, never replace a Capacitor with the one you pull out, that might not be the right one in there. Get the data off the motor tag. Secondly, the superheat is much too high. See if the TXV has an adjustable post, it just might be just a bit of spooge in it. The test with the bulb is to put it in your hand to warm it up, fooling the TXV to feed and then see if the superheat comes down. However, the diagnosis was correct, Weak TXV, …
You can pull the power wier on the condinsing fan and watch the hi side pressure climb and the suction line pressure will stay the same indicates a bad txv
40 mfd for a blower motor. Is it a 110 volts EFM. Cause here 20 mfd is used for 1 HP up to 25 nothing higher than that.,,,,,,,,I kno Lennox Furnace install 40 mfd from Factory
I guess i wanna ask the chat here if anyone could help me out if thats ok. How does one know which pressures are appropriate? is it like written on the/a general rule of thumb that your suction and head pressures should be or is it some calculations needed. I can just google this but i see so many different answers and methods it gets kinda overwhelming to filter. Thank you
There is a general idea for the right suction and head pressure according to which refrigerant you’re using. Although sub cooling will change depending on the manufacturer. And superheat is always figured by a general chart.
someone explain it to me; i thought with a TXV it tries to hold superheat constant, so why would adding it here result in a change? and how does that help to diagnose a restriction here
I learned from someone that pulling out outdoor fan during whole system is running, head pressure should go up , low pressure stays same level for awhile, Txv is good. If low pressure goes up at meantime, telling Txv is bad. Thank you for sharing your knowledge with us.
we have that test-but its very fast increase -so txv cant changed so fast
There must be a better way to check if the TXV is bad. The sub-cool was good telling that that the refrigerant is good. The airflow was good. Dirty condenser and filter would sometimes do that. But that I guess was good leaving the TXV faulty. It’s unable to let the proper amount of refrigerant into the evaporator. I am still in school for air conditioning and refrigeration so I am no means an expert but my job as a watch engineer is also plumbing and AC. When there is a low refrigerant or leak or bad TXV, I let my chief engineer whom has been doing that for 40 years take care of that. I take care of everything else so I am learning and watching those videos helps me a lot. Keep with the good work.
Low air flow would of made your super heat low,not high.It has the correct amount of refrigerant,look at that sub cool.Let’s see good on charge but superheat is off....What controls superheat?TXV check why it is underfeeding. Even more so low air flow would of made your delta t higher .
Hey man I appreciate how to really explain and how you explain in detail what you do. New tech here and actually learning about txv has been a bit challenging
Great, great video! thank you so much Josh for taking the time to record in such detail and explain. You’re a very nice and caring person!
Definitely TXV it’s slightly restricted, that’s why you have a high subcool when you started to add more refrigerant you have more liquid outside on the liquid line because it can’t get through that TXV kind of backed up. Suctions low like you said and your superheat is slightly high. It’s pretty much starving the evaporator and stimulating sort of like a low on charge that’s also why your delta T is low, not enough refrigerant going through the evaporator.
where are the videos Rico?
good video, there was a better way of testing for the txv being bad. without wasting refrigerant. block the condenser and the SH shouldnt change if it does, then you got yourself a bad txv.
very informative video. im a new subscriber. keep the videos coming.
thanks, just learned this from a video I watched earlier today
Do you mean like covering the top of the condenser?
Would it work if you disconnected the fan motor and taped a cardboard box ontop?
@@ziongiahnyes, I think disconnect fan wire , to see the SH change
@@jaybro1046what should happen when you disconnect fan motor?
Disconnecting the old fan will make your pressures spike fast, I would rather put something on top to block the fan
Great Video.....outstanding tip on verification of TXV trouble shooting!
Thank you so much for your time brother, , you are very kind and caring.
I like the probes you're using. Cool video.
Awesome video! I know I’m super late to the party but I agree the TXV is out of range and should be replaced. The only extra step I would have added is shutting down the system and watching the TXV equalize. Sometimes that will be a dead giveaway.
Can you further explain about equalization? Would it not equalize? I’m asking because I had one, and after I shut the system down for a bit I noticed there wasn’t equalization or it didn’t happen as quick as I thought it should. Thanks for the response
@@SickaMorStylewhen you shut down the system, the txv senses suction temp, so the suction line warming up will cause txv to open up hints equalizing the pressures
Good video yeah i agree those txv have a mind of their own lol can’t wait to see the follow up video.. hvac for life lol 🤙🏽
Great service call diagnosis very precise informative and useful...thanks bro 👍👍👍
I have never seen a blower fan capacitor of 40 MFD. Usually 5-10. 40 is like the size of the compressor
Thanks for the fundamentals friend!
great info, i heard of putting the txv bulb in hot water not cold.
You can do both hot or cold. Hot water would open txv to allow more refergerant in causing lower super heat, cold water would close valve causing superheat to raise
Would this also work on elctrinic sensors?
You could also as a precaution check the temperature across your filter dryer. Looks like a small liquid restriction, possibly from someone not purging the system and not brazing with nitrogen causing oxidization that could clog the txv screen, or the filter dryer. Sensing bulb may also not be secured properly or insulated.
That said looks like your on the right track.
Note for the official record, you should’ve taken the bulb off in the first place of the TV and put it in a warm bucket of water before adding refrigerant. That would be the simple solution to the problem as well is a timesaver as well.
I’ve been seeing that lately as a check to make sure it’s not stuck open or whatever but doing this could it unstick it if it is partially blocked or just sticking?
I'm 7 minutes in and screaming that you're super heat is high. How could you have an airflow problem? But i knew you would figure it out
We got a smart guy. Come on. We all think different. Ian’s it’s fine. Just because you saw that fast. All you can see is his screen. He was probably looking at other things. We always want to show that we are smart. Instagram humble ourselves and maybe even say I learned something today. Or at least give a compliment or great video.
Low air flow definitely would make everything colder...refrigeration 101
you should have a 9/16 wrench for the flare nuts. I’m old school and never use pliers on nut and bolts.
I use an Xtra small crescent brand adjustable wrench, it's the most ridiculous $12 but, somehow I find a way to use it everyday.
Why do we always have to give our two cents. Let the man do what he wants. It’s not wrong.
I thought your supposed to put the sensing bulb in something hot so we can forced open the valve not ice water. I believe that closes the valve more. just checking.
Great explanation
Thank you 🙏
You did good on this. I’m sure people will learn proper techniques from this video. I’ll be a new subscriber. I have videos as well you can learn from.
Lennox old furnace with 40 mfd blower cap. Wow never seen it that high.
I would've checked airflow first before checking the charge, but that's just me.
After all, EAR.
E-lectrical
A-ir flow
R-efrigerant
Great video otherwise. Keep 'em coming. 😏
I can see a huge problem on that furnace. The return should came in from both sides of the furnace. With that filter as dirty as it is raises static pressure and lowers CFM and can simulate a bad TXV.
Those Fieldpiece wireless probes look nice, but it would be nice if they had bigger temperature clamps.
Measure quick is way better for probes you should try it out
Great video!
i learned so much in this video. thanks lol
Thanks for showing the numbers. Most youtubers don't or will show on a tiny cellphone. Dang, you got nice tools for the job. Maybe some day I will too.
What do you think of putting the txv bulb in cold water then hot to see if its adjusting.
Piston should be charged by superheat . Txv by subcooling.
Your delta T is 11 it tells you right away you have a system restriction.
Filter dryer, or system contamination or .
You must check first if all your mechanic components are clean then see if you have a piston or TXV .
You cant charge or measure a TXV system based on superheat it have to be on subcooling.
Older Lennox furnaces loved to use those big ole 40 mf'ers . Ever since the pulse furnace days. Good diagnosis. 👍
Filter dryer should be installed on the condenser
You know…..
This TXV n 410A
Have caused more problems n forced homeowners to spend more money…. Pain and frustration.
Of course it keeps field technicians busy…but not all technicians have adequate knowledge of how to address n fix it….
Specially in sunbelt area it’s not easy to work in hot 100+ attic.
To a point it’s not worth it!
Looks like the sensing blub is loosing its charge and causing the restriction
Test txv. Disconnect cond fan and watch to see if txv modulates as it should.
What should happen at that moment
If you want to know if your txv is working, you need to change conditions. The easiest way is to disconnect the outdoor condenser fan, a properly working txv will keep superheat and suction pressure the same or just a little higher. But if it begins to climb then txv needs replacement.
Just had this problem literally today and same results normal to high subcool high superheat low delta T did a bulb test with the txv and turns out bulb had lost its charge
Great video
First, never replace a Capacitor with the one you pull out, that might not be the right one in there. Get the data off the motor tag.
Secondly, the superheat is much too high. See if the TXV has an adjustable post, it just might be just a bit of spooge in it. The test with the bulb is to put it in your hand to warm it up, fooling the TXV to feed and then see if the superheat comes down.
However, the diagnosis was correct, Weak TXV, …
What brand of tools are you using
Great video,,,,i think the TXV ,,non modulating how is should be,,,,!,,,
Is it possible to clean a txv? Or do need replacement?
Thank you b
Look at your suction temp also.. thats a dead giveaway
Could be as simple as bad bulb placement
I know I'm late to the video but shouldn't you try the cold/warm water first to try and free it up?
You can pull the power wier on the condinsing fan and watch the hi side pressure climb and the suction line pressure will stay the same indicates a bad txv
That’s a great way of doing it. I’ve never been shown that or thought of it. Thank you!! I’m gonna give it a try.
can you explain to me how to check for a bad txv? new tech learning need better understanding
I also learned a lot thanks the video was 👍
I've heard those TXV goes out faster
Thanks
Wow, an hvac video that wasn't recoreded with a potato.
What type of brand is that
It's wise to discharge the capacitor B4 checking it thanx brainiac out🤔🤪
IS THAT A SNAKES RATTLER TO THE RIGHT I AM OUT OF HERE 🐍🐍🐍🐍🐍🐍🐍🐍🐍🐍 😱😱🚑🚑🏥
Lol I didn’t notice! I’ll have to go back and look. 🤦♂️
40 mfd for a blower motor. Is it a 110 volts EFM. Cause here 20 mfd is used for 1 HP up to 25 nothing higher than that.,,,,,,,,I kno Lennox Furnace install 40 mfd from Factory
I guess i wanna ask the chat here if anyone could help me out if thats ok. How does one know which pressures are appropriate? is it like written on the/a general rule of thumb that your suction and head pressures should be or is it some calculations needed. I can just google this but i see so many different answers and methods it gets kinda overwhelming to filter. Thank you
There is a general idea for the right suction and head pressure according to which refrigerant you’re using. Although sub cooling will change depending on the manufacturer. And superheat is always figured by a general chart.
Arrange for suction and head pressures will also go up and down depending on the temperature outside. It can get a little confusing LOL
someone explain it to me; i thought with a TXV it tries to hold superheat constant, so why would adding it here result in a change? and how does that help to diagnose a restriction here
Txv should hold constant, if it doesn’t then it’s not holding SH properly
I hate residential equipment when the have txvs that are not adjustable. Txv is done bro.
Can you just change the TXV to a piston an be done with it?
Yes you can and we will do that sometimes
It depends on the system. Single stage condensers, yes you can. 2 stage and above, no. TXV is required to regulate super heat.
The sound wasn't to clear. Maybe cause of the condenser. I had it full volume still couldn't hear it loud enough.