HVAC Pump Down 2

[Skij710]

In your first vid in this series, it looks like you are just putting nitrogen into the system, turning the nitrogen tank off, then removing the hose from the nitro tank and letting it just come out, then closing it off at manifold, and then reopening the service valves in reverse order from pump down order. Is this correct?

[DrZarkloff]

@Skij710 The nitrogen is used to break the vacuum in the line set before opening it up to the atmosphere. When the work is completed on the line set then you have to evacuate the line set with a vacuum pump before releasing the refrigerant back into the line set.

[Skij710]

First of all, thank you for the great video. I have a question regarding the line set after pumping down. Is there any other method for safely releasing the refrigerant into the line set besides using nitrogen to purge the non-condensables. I know nitrogen is available, but don't need a whole tank of it. I want to move my unit to the side of the house instead of where it currently is by the back porch, which would involve a longer line set. Also can you explain the nitro step better?

[3882woody]

Thanks for the response I do appreciate. I am have a terrible time finding an evaporator coil replacement for my split system heat pump 2 1/2 ton carrier/bryant the evaporator number is a common one FY4ANF030 do you know of any web sites that will sell the replacement coil to the public. thanks

[DrZarkloff]

@3882woody If the system isn't too old you should be able to get one from a Carrier dealer. The chances are that they won't sell the part directly to you. You'll have to pay a contractor to install it for you.

[3882woody]

Hi why it is that after a pump down you have to put nitrogen in the lineset if the system is going to be opened up for the repair. (I have change the evap coil). also can you recommend a warehouse that sells evaporator coils to the public... thanks i appreciate your help Woody

[DrZarkloff]

@3882woody You don't want to open up a system that's under a vacuum to the outdoor air to prevent moisture in the air from getting in the system.

[dadanaik]

I have a leaky schrader valve on the suction side. I am unable to replace the schrader under pressure using the special yellow jacket tool due to the valve being in a very tight position.  Could I use this pump down method to replace the schrader valve(s)?

[somerandomdude82]

If the system has nitrogen in it, do you vacuum the line set before opening the service valves?

[DrZarkloff]

@somerandomdude82 Yes, most definitely.

[11sprinkles]

Dr Z, Can you pump down to the evaporator side closing off the suction first and then the liquid side so a compressor replacement can be performed?

[DrZarkloff]

@11sprinkles If you have service valves at the air handler, you could pump down a lot of the gas in the evaporator. You'll still have some gas to recover. In the case of compressor replacement, you're better off to recover all of the gas anyway.

[woodymac100]

When you open the high side then the low side on your manifold to release the left over refrigerant from the red hose into the system via the blue hose is it possible that air from the unused yellow hose could be sucked into the system? Doesn't the refrigerant travel into the yellow service hose when the manifold valves are opened? EPA does still allow you to vent hoses right?

[DrZarkloff]

@woodymac100 The gas does not have to travel through the yellow hose when equalizing the high side into the low side.

[yrtuag]

Was that compressor a reciprocating or a scroll? Isn't it advised not to pump a scroll compressor all the way down? Thanks

[ZuffaLtdDanaWhite]

So Dr. Z, in a heat pump application or 'any' air conditioning application, will the condenser by OEM design be large enough to hold all the refrigerant vapour?

Also when you incidentally pulled the LoSide into a "Hg Vac, why did you need to put Nitrogen into the LoSide giving it a positive pressure? Would it not matter whether it was - or + since you are intending to service the line-set??

Just curious, thanks a ton. -Ian HVAC 2nd year apprentice tech.

[DrZarkloff]

@ZuffaLtdDanaWhite After pumping down the system the evaporator and the line set will be in a vacuum. The refrigerant will be in the condensing unit.

[SS1971SAMUEL]

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[WinMOD42]

@ZuffaLtdDanaWhite The condenser is designed bigger to hold all of the charge when pumped down unless the units was over charged to begin with.

[WinMOD42]

@ZuffaLtdDanaWhite Your using the nitrogen to purge the system of any non- condensables and to pressure check the system for any leaks.

[erd675]

i was taught not to close off the suction side is that right?

[DrZarkloff]

@erd675 You might not have to unless the compressor is leaking back through the suction side.

[footlong87]

Those bundles of wires are bothering me, i'd be making that all nice and neat. i know that it isn't a real issue, its just something i have ocd about. Good video Zarkloff.

[DrZarkloff]

@footlong87 I believe in making wiring bundles nice and neat, too.

[b0ondockz]

How much can an hvac technician expect to make starting out, mid career, and late in their career?

[footlong87]

@b0ondockz, start out no experience 15$-20$, mid career 20$-30$ (ranges on type of hvac u do, example is refrigeration exp is a plus) 30$-45$ is a full licensed master or journeymans with capabilities to work on anything in the market today example, duct work, residential, commercial hvac, refrigeration (ice makers, rack systems, walk-in's, self contained and split), chillers, water towers, exhaust fans, blowers thats in the washington dc area, and ranges for each area and company.

[DrZarkloff]

@b0ondockz It all depends on your location and the agreement that you can make with your employer.

[mangerik]

Hi DrZarkloff, yesterday while driving my car air-cond. hose (between the compressor and the condenser) burst from the metal pipe and exploded with a very loud 'bang' . Could you please tell me any possibility, why?

[DrZarkloff]

@mangerik It sounds like your condensing coil wasn't removing heat for one reason or another so it built up pressure until it burst.

[heliboy112]

Hey Mr Zarkloff I was wondering if I could email a few questions.  Thanks keep up the great work.

[DrZarkloff]

@heliboy112 Sure. Just private message me through youtube.

[Bearfly]

Great time saver DrZarkloff, Thanks!

[SuperLuckybuck]

 HI , can you make a video on defrost boards , from were to fasten wires to , what can be trouble shooted on the board before you declare the board bad , Thanks really enjoy your videos

[DrZarkloff]

@SuperLuckybuck I do have a video on defrost boards.

[pclle]

Worst system disconnects ever made..lol, they just look so damn dangerous

[DrZarkloff]

@pclle I kind of know what you mean. Commercial disconnects can have that "dangerous look", too.

[AMD1]

is that oil under your liquid king valve? This video is very informative, and I love the slogan on your manifold.

[DrZarkloff]

@AMD1 Thanks. No oil.

[tubeyouj]

Hiya Dr Z. Great video! :) We got some new systems at my TrenholmTech college and we were pumping down the old systems so your video came really handy, thanks!

[DrZarkloff]

@tubeyouj Thanks for watching.

[starchild2121]

Awesome Dr Z!! I nailed my final and am a Tech now, thanks for all the help!! :)

[DrZarkloff]

@starchild2121 Congrats.

[tpal79]

What is the purpose of pumping down the system?

[ccraig2008]

@tpal79 to cut the line sets if you were changing out the condenser or air handler, if you didnt pump it down before cutting the lines you would have one hell of a mess

[DrZarkloff]

@tpal79 It's so that you can service the line set and evaporator.

[487livespot]

awesome vids you should think about becoming a teacher or something. i have my whole HVAC class watchin your youtube channel!

[DrZarkloff]

@487livespot Thanks for watching.

[tstatech]

DANGER WILL ROBINSON, - Don't forget to purge the air from your manifold and hose set before closing the high side because as it pumps down and you are closing the suction valve all the Gas - and AIR if present in your gauge set will be sucked into the system.

It's also a good practice to slowly bleed the high side hose back into the low side to prevent slugging the compressor. Especially if your using a long or 3/8 hose.

Sorry about being a know-it-all but this is important.

[chopperguy2]

@tstatech Very good point for everyone.

[DrZarkloff]

@tstatech Thanks.

[Aussie50]

Another great video!. I like your commercial/industrial ones best, like the Mcquay chiller.

[DrZarkloff]

@Aussie50 Thanks. I wish that I could do more commercial videos.

[ibunregistered]

Nice thorough step by step. Is taking that cover off a force of habit? I like Mr Lizard, his friend Mr Wasp is the pitts.

[DrZarkloff]

@ibunregistered Mrs. Blackwidow spider can be a real pain, too.

[itscool1968]

did you do this on youre own system again:)

[DrZarkloff]

@itscool1968 Yes.

[itscool1968]

@DrZarkloff better not brake it or the wife might make her one video ac tech gets hung:)

[DrZarkloff]

@itscool1968 LOL

[Lachlant1984]

I don't know too much about air conditioners, so can you please explain in layman's terms why you would want to do this?

[Aussie50]

@Lachlant1984 I do it when I have to remove lines and re-locate a system without recovering gas. likewise if Dr.Z wanted to replace a indoor coil or TXV on a central system he could pump it down and isolate the gas in the outdoor unit.

[Lachlant1984]

@Aussie50 Yeah, OK, I understand that. This may be a really stupid question or assumption, but I assume you don't need to do this on a window unit/box unit arrangement. But you would need to do this on a split system, right?

[DrZarkloff]

@Lachlant1984 It's done so that you can service the line set and evaporator.

[mechanicwarrior20]

good job :)

[DrZarkloff]

@mechanicwarrior20 Thanks

[Tranixx]

thumps up if you heard the intel song in the backround ;)

[johnt22007]

after you removed the refrigerant from your hoses, the manifold still reads pressure. what do you do with the left over refrigerant still in your hoses. Do you just purge both hoses, or do you hook up to another system? whats the proper way to clear your gauge set of refrigerant before hooking up to another system. thanks!

[DrZarkloff]

@johnt22007 I'll usually just connect it to another system as long as I know that the gas in the gauges is clean. If the gas is contaminated, I'll recover the gas and sweep the gauges with nitrogen.