HVAC Thermal Expansion Valves

[metaljesus]

this guy is an idiot

[Charles2337]

Isn't the "powerhead", called a diaphram.

[DrZarkloff]

@Charles2337 Actually, the power head is called a power head.

[Charles2337]

@DrZarkloff

... okay. But in that "powerhead" is a diaphragm.

[DrZarkloff]

@Charles2337 Actually, the powerhead is filled with a refrigerant that is different than the refrigerant that's in the air conditioning system.

[Charles2337]

@DrZarkloff

The refrigerant is actually stored in the sensing bulb and travels down the tube to the diaphragm. Also, not all bulbs contain a different refrigerant than the refrigerant used in the system; it depends on the application.

[150grnballistictip]

Do they sell rebuild kits for the txvs, or if it's the same unit can you just replace the internal parts and bulb from the body saving the brazing. Haven't had any experience with txv's as all my units are fixed orifice.

[DrZarkloff]

@150grnballistictip You can buy the power head separately but you need to buy the entire expansion valve to get the inner parts.

[abarley37]

I have never heard tje term TXV to hunt, can someone help me with that term? TY

[henryvideos100]

How do you replace a reversing valve solenoid coil on a reversing valve?

[DrZarkloff]

@henryvideos100 The solenoid coil usually is just bolted on or clamped. Just remove the old coil and replace it with a replacement coil with the same coll voltage.

[fyp777]

Dr Z

what cause the TXV to Hunt?

thank you

[DrZarkloff]

@fyp777 Some refrigerants will cause a TXV to hunt. An other cause is when the charge is way too low.

[1theborder]

@DrZarkloff a question what is the sintom when the txv is bad?

because i just replace one but the presure in low side is very low and the high very high and kill the compressor

can you please tell me the sintoms

i think is look like restriction right

[archeryman5000]

@1theborder Most likely the power head lost partially its charge, then someone put on a low side gauge and found the super heat high and the suction low, so they added refrigerant causing the head pressure to rise and maybe even for the unit to work for a while in the new condition, but then the powerhead fully lost it charge and shut down, all refrigerant pumped into the condense and head pressure went through the roof.

[fyp777]

Dr Z

what cause TXV to hunt?

thanks

[TYMENIOUS]

hi haters

[aki854]

how to adjust a 5ton expansion valve, its max turns are 8.

[DrZarkloff]

@aki854 You'll need to play around with it to see which position will give you the correct superheat.

[lvlik9]

Also can a condenser get clog up on the inside like a radiator...

[DrZarkloff]

@lvlik9 It's rare but, Yes it can. 

[lvlik9]

I change the orifice tube and the accumulator in my truck,but it's not getting cold like I want it to(60 degress out the vent..with 80 degress ambient temp) ...everything else is use....compressor,etc...and by the way the a/c didnt work when i bought the truck...

[DrZarkloff]

@lvlik9 Auto air is a bit different than stationary air conditioners. But a 20 degree delta T seems good to me.

[lvlik9]

Let's say you are done pulling vacuum on a system and you are ready to charge it. Do you charge it while its still holding vaccum or do you release the vacuum first...

[DrZarkloff]

@lvlik9 You charge the system while it's under vacuum.

[lvlik9]

I'm working on a expansion valve on a car, about the temperature probe, the factory had it glue on to the evaporator tube with tar or some kind of black stuff, do I have to put it back where its at or can I just stick it into the evaporator fins, if not where can I get the tar or glue so I can put it back on the evaporator tube.....thanks

[DrZarkloff]

@lvlik9 The temperature bulb needs to be insulated with the "black stuff". It's called cork. You can get it at any HVAC parts house.

[LoneWolf071]

It should be mentioned that the vavle size that you point out is in nominal tonnage. In order to properly size a TXV you should do the calculations from the sporlan chart to compensate for the expected pressure drop ambient temperatures liquid line temperature and such. I see TXV installed improperly all the time because they are installed using the nominal tonnage and are installed in a system that operates out of idea conditions.

[heliboy112]

Thanks so much for doing these videos if I need to know something I know you have the answer. Keep up the great work.

[DrZarkloff]

@heliboy112 Thanks for watching.

[711sanchez]

@DrZarkloff So good!!!

[niaz4one]

Dear Dr,

i really thanks to you b.c i have learnt alot of things from your videos

[DrZarkloff]

@niaz4one Thanks for watching.

[rossyedua]

Thanks for been a good teacher god bless you sir

[DrZarkloff]

@rossyedua Thanks for watching.

[thisisnotyours1]

DrZarkloff, what purpose does the equalize line served? why do we need it and how does it works? Thank you.

[DrZarkloff]

@thisisnotyours1 It's a safety device. It equalizes the pressures between the high and low sides if the pressure builds up too much and when the system shuts down.

[hpaddyh]

@thisisnotyours1

it's purpose is to compensate fore eccessive pressure drop across the evaporator.

Most all DX systems have that config. Safety device Dr. where did that come from?

[54433001]

do you have any videos on expantion valve problems when to change

[DrZarkloff]

@54433001 Not at this time. Thanks.

[dianemarie909]

how do you know when it stops working learning refrigeration

[DrZarkloff]

@dianemarie909 Many times the suction pressure will drop significantly.

[54433001]

@DrZarkloff thank you

[blissJesus1]

Dr. Z, How do I contact your personal message

[DrZarkloff]

@blissJesus1 It's best to just personal message me through youtube.

[mralansi1]

sir I have waited for long time to have a master in hvacr . u r the best I THANK YOU SIR MR.ALANSI

[DrZarkloff]

@mralansi1 Thanks for watching.

[DrZarkloff]

@mralansi1 Thanks for watching.

[nick198101]

hi dr zarkloff. i have bit trouble abt how to re gas INVERTER A/C unit. could u pls produce a video for it .. cheers

[jayswal1001]

can you send me a 3-d model

[DrZarkloff]

@jayswal1001 I don't have a 3-d model laying around. There might be one somewhere on the internet.

[whyms1]

Hay how do you service a walk -in cooler

[jimwillfixit27]

hi ....why would you unsolder a full expansion valve if faulty,when all the internal parts and the power head can be changed,or are you talking about an first install.........thanks

[DrZarkloff]

@jimwillfixit27 There are times when the expansion valve body needs to be replaced. One of the reasons is if you're retrofitting a system with a different refrigerant or if you can't buy new parts for the old body.

[nick198101]

hi could u pls make vieo for hw to re gas sys with using super heat. im sooo confuse with that, cheers

[DrZarkloff]

@nick198101 I have a video up right now that shows how to superheat in a charge using the Fieldpiece HVAC Guide.

[salimnanhack]

when and why do change an expasion valve

[DrZarkloff]

@salimnanhack It might be necessary to replace an expansion valve if the powerhead has gone bad if it can't be removed from the TXV body.

[dennisthemenaceru]

if a powerhead lost its charge, u should be able to replaced just a power head without recovering the refrigerant, is that right?

[DrZarkloff]

Yes. You could just pump down the refrigerant into the condensing unit. That will allow you to easily replace the power head as long as you have the type of TXV that allows you to remove the power head.

[COBRIETE]

How and when do you adjust a txv.

[DrZarkloff]

You make adjustments to the TXV to get the proper superheat across the evaporator.

[rolando7120]

so the external equalizer puts pressure to open the valve more or allows refrigerant to flow through it

[DrZarkloff]

The external equalizer allows the system to equalize during the off cycle.

[batcat988]

thank for the ticks wold u be a able to show me how to clean a furnest that has a pilot lite

[DrZarkloff]

I don't do many gas furnaces. I'll keep it in mind for when I do. Thanks.

[batcat988]

can u show how to clean a heater with a gas line that has a pilot

[Wecamefromthestars81]

It would be awesome if you had Norman go out to a job with you and schooled us on HVAC....that would be hilarious!

[DrZarkloff]

Thanks. We have a video like that in the works.

[CountryComesToTown]

Thanks James for the shoutout! I'm sorry I'm just now seeing this but the video wouldn't load before for some reason. It's great to get to know both you and Becky. -Jim

[DrZarkloff]

Thanks for stopping by.

[winkhvac]

very nice video dr.

[DrZarkloff]

Thanks.

[SaintWilliamIII]

Thanks Dr. Z, this is a great video. I'm learning more and more thanks to the knowledge you share with all of your viewers.

[DrZarkloff]

Thanks for watching.

[kmjpcm63]

Dr Z. - I keep a miscl. sizes of pipe cleaners( from my wife's hobbies) , to clean the push rod guide areas when Im checking a TXV that is in a system. - It works great at cleaning without hurting the guide areas- good video kmjpcm63.

[DrZarkloff]

Thanks. Great idea with the pipe cleaners.

[icu812hardhead]

great video thanks for showing the disassembly of the TXV one of your best so far

[DrZarkloff]

Thanks for watching.

[itscool1968]

i like the actual van shots the vr van shots are good but its more fun when ya sitting in it:)

[DrZarkloff]

Thanks. I'll keep that in mind.

[V8Jagnut]

very good vid. its just like cats. some cars have a H type TXV.

[DrZarkloff]

Thanks. I guess that if you've seen one expansion valve then you've seen them all with a few exceptions.

[V8Jagnut]

yep. have you seen a H block type?

[DrZarkloff]

No, sorry I haven't

[V8Jagnut]

ill do a vid next time i come across one. it goes on the liquid and suction lines. at the evaporator.

[Aussie50]

Fantastic video Dr.Z!

I never did a cutaway video on a TXV simply because I don't have your level of knowledge on how these work!.

[DrZarkloff]

Thanks for watching. The brass is probably worth scraping.

[Aussie50]

yea I usually remove the SS powerhead and toss them in the brass bin, good ot see how they work though!

[fs1]

Nice one....Thanks....Wish my instructors would field strip stuff like this in class and explain. Thank you, very helpful

[DrZarkloff]

Thanks for watching.

[fyescas777]

Once a txv is brazed, for how long do you let it coll before re assembling the parts?

[DrZarkloff]

Just make sure that it's cool enough to touch.

[diymania]

I find old TXV´s good for parts like springs and metal pins.

[DrZarkloff]

Yeah, I guess you never know when you'll need a small spring.

[IChoseTheRedPill]

good job...

[DrZarkloff]

Thanks

[imaflirt247]

Great Video 5 stars all the way.

HackFree!!!

[DrZarkloff]

Thanks

[jhansen2085]

Do you have a blue screen nnow?

[DrZarkloff]

I have a green screen.