# 2.5 ton goodman coil flowrater



## slash5bmw (Jun 18, 2010)

I have a bryant condenser and the label says that I need an air handler with a txv. I have 2.5 ton goodman ARUF303016CA air handler and the "F" in the model number means it has a flowrater metering device.

Is it possible to replace the flowrater with a TVX? 
Please look at the attached photo. I'm not sure where the flowrater device is located.

Thanks for any help.

Slash


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## Doc Holliday (Mar 12, 2011)

You remove the lock nut, place the piston/flowrater into that line where you just removed the nut from, attach the short piece of 3/8th's copper which should have been supplied with the coil with the use of that nut (short piece of copper inserted through the nut ) you just removed and tighten it all down.


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## Doc Holliday (Mar 12, 2011)

Don't forget to install the rubber O ring as well. Might already be one inside when you remove the nut.


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## slash5bmw (Jun 18, 2010)

I haven't removed the nut yet. I was going to do that when I'm ready to braze the lines.

The AH is new and it didn't come with a flowrater. I do have the little copper tube(it was attached to front panel of the AH). The condenser is 2 years old and it's a 2.5 ton Bryant.

The label on the Bryant condenser says to use a TXV. Is it possible to get a TXV for a 2.5 ton AH and install it on this evaporator?

Thx

Slash.


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## Doc Holliday (Mar 12, 2011)

The piston would come with the condenser if condenser were new. Air handler's (evaporators actually) can be used for multiple size condensers, why the piston comes with the condenser, to match the compressor's tonnage. 

Yes, you can buy a txv and use it. Make sure the refrigerant type is correct as well as the size.


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## Doc Holliday (Mar 12, 2011)

Tip: remove the nut, thread the small piece of copper through the nut, braze the fitting to the line AWAY (not connected to) evaporator and then tighten the nut/line back to the evaporator with the piston now installed. This way you won't burn the O ring/seal. 

If you'll be using a txv then same difference except there will not be a piston installed.


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## slash5bmw (Jun 18, 2010)

Thanks Doc. Both condenser and AH are 2.5 ton and use R-22 so I'm good there.
I won't braze the TXV while it's connected to the evaporator. 

Will any 2.5 ton txv work? Are there any makes to buy or avoid?

I'm going to pick one up tomorrow.

Thx

Slash


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## Doc Holliday (Mar 12, 2011)

They're all the same. Just make sure the txv is r-22 specific.


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## slash5bmw (Jun 18, 2010)

There's a rectangular plate next to the nut that I removed from the access panel. 

I guess the txv will be outside the insulated air handler. Please let me know if this is how everything gets brazed.

1 - I have the 3/8 liquid line from the condenser brazed to the txv (txv covered in a wet rag so nothing gets damaged)

2 - I put the nut over the copper tube and braze it to the other side of the txv. 

3 - I screw the nut to the evaporator.

4 - I heat up the cap on the suction line and pull it off. 

5 - I create an inverted loop and braze it to the suction line.

Am I missing anything?

Slash


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## beenthere (Oct 11, 2008)

Doc Holliday said:


> They're all the same. Just make sure the txv is r-22 specific.


Not exactly. The fitting ends are different.


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## Doc Holliday (Mar 12, 2011)

Bt's right, again. :laughing:

Watch a few videos, slash. Here's one. 

http://www.youtube.com/watch?v=HXJjGJP9oRo


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## slash5bmw (Jun 18, 2010)

Thanks guys. My liquid line is 3/8th. How are the ends different? 

Will they fit a 3/8 the line?

I guess I will keep the txv inside the AH panel and just have the liquid line going through the panel.

There's a rectangular plate that screws into the panel but I might be able to push that in so the txv is inside the AH.

Thx

Slash


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## beenthere (Oct 11, 2008)

The end that goes to the coil can be different.


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## slash5bmw (Jun 18, 2010)

BT, I assume that end is the piece that will be brazed to the little copper pipe with the nut. Is the size different.

Do I need to bring the little copper fitting in when I buy the txv to make sure it fits the txv?

Thanks for your help.

Slash


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## Doc Holliday (Mar 12, 2011)

I'd leave the txv external and wrap it, the bulb that attaches via a strap to the suction line, well in insulatube using DUCT TAPE to seal it tightly. Don't be shy with the insulation around the txv bulb either. It needs to ONLY sense the line temperature, no surrounding ambient temps whatsoever.


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## Doc Holliday (Mar 12, 2011)

This is what yours will resemble once installed although you can not see the bulb strapped and wrapped in this pic. Notice the flange/screw together fitting on this one at the evaporator, what BT was referring to, I believe. They have different ways to attach.


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## Doc Holliday (Mar 12, 2011)

This is a little better.


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## Doc Holliday (Mar 12, 2011)

Also, make certain that there is not a piston in that nut connection. If there is, remove it but keeping in mind the O ring remains. You don't want both a piston and a txv. :thumbup:


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## slash5bmw (Jun 18, 2010)

Thanks for the pics Doc. They are very helpful.

I will install the txv outside the AH.
I will see if I can get some insulation tape and a copper strap when I buy the TVX tomorrow.

I will secure and insulate the txv bulb to the suction line so it senses only the line temp and not the ambient temp.

When I I remove the nut, should I just see a hole in the tube? I'm not sure what the piston is supposed to look like but I don't think anything is behind the nut.

Thx.

Slash


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## Doc Holliday (Mar 12, 2011)

It should not have the brass orifice piston in the line with a txv. If it is there simply remove it. It just sits in there, should slide right out. 

These days manufacturers are putting them behind the nut, pretty much so that if we as a contractor go and and pick up a 4 ton evaporator coil and the piston is in it then it's ready to go. Now if we pick up a 3.5 ton condenser that has a piston taped to it's service panel along with the 3.5/4 ton evaporator that has the 4 ton piston in it, we'll remove the 4 ton piston from behind that nut and put the piston which came with the condenser in it's place, thus making the same coil 3.5, all by way of piston. Txv will match the compressor regardless, line temp, as yours will.

Anyway, that's what you'll be looking for behind the nut.


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## slash5bmw (Jun 18, 2010)

Great pictures of the piston and explanation. I will remove the nut tomorrow and let you know what I find.

Thanks again.

Slash


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## tima2381 (Feb 24, 2007)

Doc Holliday said:


> You don't want both a piston and a txv.


How would a system with both piston and TXV behave?


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## Doc Holliday (Mar 12, 2011)

tima2381 said:


> How would a system with both piston and TXV behave?


Like there was a restriction in the refrigerant lines. Low suction, high head. No coOl.


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## tima2381 (Feb 24, 2007)

Doc Holliday said:


> Like there was a restriction in the refrigerant lines. Low suction, high head. No coOl.


Is there any way it would work right? I'm asking because this was tossed around as a possible cause by a tech who wanted to replace my TXV after I just had my evaporator coil replaced by another tech. After a couple weeks, the system was cooling at a subpar level, and he found lowish pressures and low superheat and subcooling, like 2 F each. After he proposed replacing the TXV, I asked if he could test it, and he dunked the bulb in a glass of hot water, which did nothing. He left the bulb hanging, so after he left, I tried it with ice water, and the suction line temp rose 10 F, and it dropped back when placed in hot water. I eventually strapped it back on the suction line, and the system has been cooling fine ever since, about three weeks now. I put a set of gauges on and got 6 F subcooling and 11 superheat under the same conditions as before, which is nominal per Goodman's specs. The second tech didn't add any refrigerant. I'm definitely going to wait for it to malfunction again before having the TXV replaced, but it's been nagging at me.


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## Doc Holliday (Mar 12, 2011)

Seeing as how it's not a complete blockage, having both the piston and the txv installed, theoretically I could see it somewhat working but the charge would be off. I could see a tech overcompensating the charge to try and offset the restriction which could very well lead to no superheat. Then once the txv began working and closing off the refrigerant per line temp the superheat would rise as the subcool would possibly lower. 

It could very well just be the txv not working to begin with.

I'd have to agree, leave it alone.


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## slash5bmw (Jun 18, 2010)

*txv photos and gaskets*

Here are some photos of the txv I purchased yesterday.
I received 2 white teflon gaskets in the kit. 
There seems to already be a blue gasket on the txv.
Should I replace the blue gasket with the white gasket?

Thx.

Slash


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## slash5bmw (Jun 18, 2010)

*clamp*

Am I missing a part to mount the bulb to my suction line? 

I only received this part in the kit. 

Do I just squeeze this clamp around the bulb and the suction line and wrap it with insulation tape?

Thx

Slash


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## slash5bmw (Jun 18, 2010)

*txv non-bleed type*

In the txv installation instructions, it states that the txv is of the non-bleed type, therefore the outdoor unit must be able to overcome the unequalized pressure at start up.

Is there anything special that needs to be done, after pulling a 500 micron vacuum and adding to refrigerant to the system, to overcome the unequalized pressure at start up?

Thanks.

Slash


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## Doc Holliday (Mar 12, 2011)

1.) Gaskets are the exact same so it's up to you. 

2.) That is a clip which will hold the bulb to the line, it's correct. Just insulate the bulb very well and tape it sealed.

3.) The compressor will work on start up, don't sweat it. What you might want to add to the condenser is a 5-2-1 Compressor Saver/ Hard Start Kit. This amplifies compressor's starting power as well as saves the windings of the compressor which can and will last longer.

All it is is a very, very big capacitor and a relay which removes the super capacitor from the circuit as soon as the compressor has started. It slams the compressor into motion and then removes itself, all within a fraction of a second. 

http://five-two-one.com/


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## slash5bmw (Jun 18, 2010)

Thanks Doc.

It just looked like the clip was missing a piece to snap it together after putting it around the bulb.

What kind of insulation do you recommend for the bulb? The black tube type that wraps around the suction line?

The one video shows a special insulation tape. Can I just wrap it with silver duct tape after I put the black tube insulation around it?

I can also wrap it with R8 fiberglass insulation.

I will buy a 5-2-1 compressor saver.

Thx.

Slash


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## tima2381 (Feb 24, 2007)

slash5bmw said:


> What kind of insulation do you recommend for the bulb? The black tube type that wraps around the suction line?


Tube type is fine. You'll have to custom fit it, of course. Whatever you do, stay away from Armaflex-type insulating tapes that go directly on the pipe. The residue Armaflex leaves behind is a PITA to get off. Think electrical tape and multiply the evil by 1000.


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## Doc Holliday (Mar 12, 2011)

Yup yup, insultube and duct tape.


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## slash5bmw (Jun 18, 2010)

*connection for txv*

I think I can hook up the txv to the schrader valve built into the coil.

Is that recommended or should I braze on the fitting supplied with my txv kit?

Also, I thought the end of the suction line had a cap on it but with closer inspection it looks like there's a plug in the tube. It looks like the outside suction line gets pushed into the suction line on the coil.

How do I get the plug out of the coil on the suction side?

Please look at pic.

Thx

Slash


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## Doc Holliday (Mar 12, 2011)

If you can screw the txv onto the coil's female threads then do it. It will work, just remember the O-ring. 

That suction line 'plug' you're going to need to cut with tubing cutters about halfway. Best bet is to either unscrew the high side nut or use a screw and drill into the suction 'plug' to de-pressurize the coil first. You're going to need to remove that screw to release pressure if you go that route. On that note, if nitrogen does indeed (as it should) come out of the coil when you perform either of the two procedures, then your coil is good, no leaks from the factory.

Once that plug is cut in half, you're going to need to reem it out a bit to get the copper line to fit in there. Use some pliers, sticking them into the now open plug and twist them around with a bit of force, opening up the lip of the now cut plug. There most likely will be a few metal shavings left in there so use your finger and get them out.


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## slash5bmw (Jun 18, 2010)

Thx Doc. 
I believe the threads on the coil for the txv are male threads. There is a schrader valve inside the threads. I should be able to unwind the txv to reach the threads.

I will depressurize the system by removing the liquid line nut. I'd like to cut the suction line as close to the end as possible so I'm farther away from the access panel as possible.

What do you use as a heat shield around the air handler when brazing? 

Thx

Slash


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## Doc Holliday (Mar 12, 2011)

Best to use an old metal cover of any kind, like if you have an old condenser, remove the service panel and cut it to be able to fit around the copper. If not available, use aluminum foil tape and a lot of it and again, try your damndest to not point the flame towards the coil. If you begin to melt anything or a small flame occurs such as on the tape or the rubber gasket of the coil than a simple strong breath of air will knock it out. Keep a spray bottle of water next to you as well. Sometimes the inside insulation likes to catch fire. 

Almost feels like I've installed a complete system myself..:laughing:


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## slash5bmw (Jun 18, 2010)

Yeah, this thread will be a good place to newbies.

Thx

Slash


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## slash5bmw (Jun 18, 2010)

I took the service panel off the condenser and the top of the capacitor is rusted.
I attached a photo.

Does the 5-2-1 compressor saver/hard start kit replace the capacitor or would I mount it on top of the capacitor?

Thx

Slash


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