Recharging a Refrigerator

[RayPooley]

Recharging a Refrigerator?

Why here on a plumbing forum?

I am talking about fitting a recharging valve to a fridge that doesn't have one and that involves pipe work rather than electrical.

So I figured plumbing rather than electrical. It's a long shot I know but here goes.

I can see on the net that you can buy recharging valves that you can clamp on to the refrigerant line like the one below.

Have any of you done anything like this? How did it go?

Which line should it go on? The top one? Images attached.

I don't want to break out the torch and solder.

Thanks .

 

[king of pipes]

Don't mess with stuff you don't know about is my advice get a F gas engineer to do the replacement safely. Kop

 

[Timmy D]

I’ve got my F Gas, this is not something you want to be doing.

It’s a sealed system. It should never need recharging if it is working correctly. If it needs recharging, that means there is a leak which needs to be found and repaired.

If it’s a pipework leak, all refrigeration lines are brazed, not soldered.

It will also need a certain weight of charge. This requires scales and knowledge.

The system should also first be purged of moisture before the charge. This requires OFN gas.

It should also be vacuumed. This requires a vacuum pump.

An accidental release of refrigerant can cause serious injury.

This isn’t a diy job.

Typically, it’s not cost effective to fix fridges unless they’re large/expensive. With most small domestic fridges, you can buy a whole new fridge cheaper than a new compressor. Work that one out?! Lol.

 

[marvoni]

As above it's not advisable to do this unless you understand the risks involved.

Even if you do install the valve you're not going to be able to do anything constructive without a vacuum pump, refrigeration gauges, hoses, freon gas, charging scale etc. Just blindly putting gas into a system you think might have a leak is going to end in tears and could even be dangerous.

If the system does have a leak it needs to be repaired then the system needs vacuuming before regassing and also a new filter/dryer also needs to be installed. When a 134a system like this is short of gas it will run in a vacuum which sucks non-condensables (air), debris and moisture into the system which all need to be removed. Also 90% of leaks on domestic fridges (assuming it's not caused by a kitchen knife defrost) will be on the pipework buried deep inside the foam so it won't be repairable.

The piercing valve you've shown is better used on the stub of copper pipe (not aluminium or steel pipes) on the suction side of the compressor. Even if you diligently clean the pipe first with Scotchbrite those types of valves are notorious for future leaks because they're cheap and nasty and use just a small buna-n o-ring compressed against the curved wall of the pipe to achieve a mechanical seal. It's far better to braze a Schrader valve onto the pipe but not normal solder which isn't strong enough to withstand the pressures involved.

 

[RayPooley]

This is for the benefit of those who might follow on who are interested in this repair.

Here is my experience.

It has actually been two weeks since I did this repair. I wanted to wait to see how effective the repair was before reporting back as to its efficacy.

Having failed to gather any useful input from elsewhere in the end I contacted the manufacturer of this item for advise on its application. This devise must be installed on the suction side of the compressor. In my particular case my concern was the fact that the suction side consists of a 5/16" aluminium pipe rather than copper.

The manufacturer told me that they hadn't tested it on aluminium but on copper. As you know
aluminium is softer than copper. They confirmed there would be no problem from a piercing perspective. Their engineers also confirmed that they wouldn't expect any performance issues
either. So I was ok to proceed.

I should point out that I also considered the blanked off process tube that is used on the production line for priming the refrigerant. That was also 5/16" diameter but copper not aluminium. But I opted for the evaporator pipe because it is longer.

The first thing I did was to check for leaks using a thick solution of detergent which revealed nothing. While the unit is running.

Moving on, I turned the fridge off at the mains.

I then presented the valve to the pipe making sure it was in a position to make it easy to connect the refrigerant hose connector to. You have to make sure that the piercing tool is fully retracted before you do this and the the small rubber o ring seal is firmly in place in its seat around it.
That last bit is very important.

At this point,if you are happy with its position, you can then fully clamp the valve in place.

Then you pierce the pipe in the prescribed manner after which you cannot move it.

I retested the valve for leaks and found it to be sound.

The valve claims to be suitable for 1/4", 5/16" and 3/8" OD pipe. To be fair I wouldn't try using this on 1/4" pipe. I presented it to a piece of 1/4" pipe and didn't feel comfortable with the security of the fit. Even with the spacers/adapters provided for the 1/4" option.

But the 5/16" fitting feels really secure. I would imagine the 3/8" would be more so.

So I connected my refrigerant hosae/gauge up to the valve.

The pressure was -3 psi. Doen't seem like a lot but apparently enough to stop the fridge from cooling down enough to trip the thermostat. That was my problem. No less than 6C in the cooler and continuous running.

I then turned the fridge on and left it running for an hour withe the gauge attached.

On returning the pressure reading had changed to -4 psi.

I then started opening the refrigerant valve up in 3 seconds bursts waiting a few minutes between each burst to allow the gauge to settle between each blast until the gauge read 4 psi.

2 to 3 psi is enough but I was aware that I might lose a little when disconnecting the filler hose from the valve so I went to 4 psi. Indeed there was a bit of a hiss of escape as I was unscrewing the connector as you might expect. Unavoidable really. You should do this as quickly as you can.

I tested the valve for leaks again after removing the connector. All good. In any event the valve comes with a sealed screw on cap just in case which is good.

Finally, I popped a thermometer in the cooler cabinet and waited.

The outcome? Within 20 minutes the thermostat tripped and the compressor switched off.

The thermometer read 4C.

Continued to monitor over the next 24 hours and the fridge is now working as it should.

It is now two weeks later and everything is fine.

The great thing about this fix is that it has kept another otherwise perfectly serviceable refrigerator from hitting the already overburdened refrigerator scrap heap at least for the time being.

This is not a bad thing if you are pro recycling.

Not having to spend £270.00 on a new fridge either is a considerable incentive too.

It is easy to do provided you take your time and follow this process.

Hope this helps.

 

[Timmy D]

Although my first post was not helpful in completing this process, I’m just writing to say I appreciate the time you took to update this post.

Well done.

 

[John.g]

Who remembers the (Freon) F22 & F12 days?.

 

[Ric2013]

Who remembers the (Freon) F22 & F12 days?.

I still have a working R12 fridge. Don't use it often, but until I need that space I retain it as a backup. R12 was a far better refrigerant than any of the replacements. Apart from its reaction with ozone under conditions of high UV light...

 

[John.g]

Spent a fair bit of time on refrigerated ships with R22, very little problems, main work was hot gas defrosting especially at the start of the voyage, might overhaul one of the reciprocating compressors on the run back.