Fixing Refrigerant Leak on Trane Heat Pump
I had a service tech out to find and fix a suspected refrigerant leak on my new Trane XL16i heat pump that was installed in May 2007. As I've had some problems with my install, I wanted to see if you had any comments on whether this process sounded about right.
First I showed the tech where I had seen and felt the oily drips from the liquid line joint as it enters near the indoor coil just above the furnace. He didn't see an obvious leak there and quickly started looking around the coil and on the suction line and near a "charging valve". He used some detection equipment and then some soapy liquid but with no real success. He thought he saw one small bubble around the schrader valve at this charging valve. He thought it could have been a problem from the factory and thought a little tighten would solve the problem since he didn't see anything else.
Fortunately as he was closing everything back and cleaning up I showed him again where I'd seen the oil drip and sure enough there was now a small pinhole with what looked like tiny shaving cream (refrigerant) coming from the hole.
I guess it was an obviously poor soldering job of this joint during the initial install but this was the first time I'd ever seen the actual leak. Maybe it was growing.
Here's my layman's version of the process the tech used to fix the leak:
1) He turned system on cool, I think to move the refrigerant out to the outdoor unit/side.
2) He decided to re-solder the joint with an acetylene torch with oxygen instead of replacing/soldering with a new joint coupling. Thought he could do it with "less temperature" around the system.
3) He then pulled what he called a "deep vacuum". This lasted abot 20 minutes and the gages went down to what looked like -30 PSI (guessing that's 30 PSI below std atmospheric pressure) on his gauge.
4) He then added some R-410A using some guidelines within the heat pump. He indicated he added too much at first and then let some out. He said he added about a pound. It was around 40 degrees outside at the time.
At some point either before step #3 or #4, he had me turn on the heat pump in heating mode. I know he had it in heat mode when he was adding refrigerant.
I know I've read some things about difficulty getting the right charge in colder weather. Are there any other things in this process that could be a problem in the future? I wouldn't ask except for the fact that I've had several problems with/after my initial install.
Thanks for any concerns or reassurance you can provide.
Humm? where are you from? what country? Sounds like he knew what he was doing? I wouldnt nit pick the guy!
Was this the only problem with the unit? just a little oil spot? but if you really want to nit pick i found this on r-410a because ive never used it!--
the new r-410 (chlorine) may have something to do with the leak in the copper!!!
There has recently been a change in the use of gas for air conditioning plants: it has gone from halogenated fluids, rich in chlorine, or partially halogenated fluids, such as R22, to hydrofluorocarbons free from chlorine atoms, 407 and 410. These last refrigerants are gases that contain hydrogen and are thus more soluble in the atmosphere and therefore less noxious.
The safety systems of air conditioning units have in fact been improved by new rules that require a certification of the most relevant components.
The copper pipe, for example, must present particular characteristics to comply with DPR n° 447 and with the EN 12735 regulations.
A self-flare fitting substitutes the flare fitting in a fast and safe manner. The brass alloy nut guarantees a better sealing compared to traditional hand made flares on copper pipes and doesn't require substitution following repair and maintenance operations.
Following these improvements, the air conditioning unit is able to safely bear the higher pressures of the R410a gas inside the refrigeration circuit.
The 410 gas is the gas that best meets the requirements for stability, non-toxicity, uninflammability and high thermodynamic efficiency at the present time.
If we wanted to synthesise the characteristics of the new gas, we would have to study the thermodynamic efficiency: the R410a gas is more efficient because it is able to create maximum thermodynamic efficiency inside the unit without any waste and expensive leaks.[/COLO
Say What?? That process of leak detecting and repair is fine...nuff said.
so a leak was found, it was fixed. He even was honest enough to tell you he over charged it at first but corrected it, now the unit is working.
whats the problem?
should be good to go, reBRAZING the joint is a common practice, no need to cut out the original joint. If it was a larger leak and the unit had run into a vacuum at all(would require more than a 1 lb loss of charge, I would have recovered and recharged the unit and replaced the liquid line drier, but for this particular leak he did fine in my book.
Originally Posted by eswells95
You can't fix stupid
Sounds like he did ok. Cold weather charging usually isnt a problem unless its a/c only. Ive never had a problem charging a heat pump in cold weather (other than keeping the bottle warm).
Ok- so at what point do most of you decide to pull a 410 charge (it is a blend- correct?) after you know theres a leak?
I was under the impression that blended ref. leak at diff. rates?
At what point do you recover the entire charge?
We would recover if the unit got low enough to pull the low side into a vacuum. Trane isn't known for using low pressure switches but they might being a 410 unit. If so, that would protect against the suction side getting too low.
The part that scares me is lack of a micron gauge to confirm a deep vacuum was really pulled. You can't tell anything accurately by looking at the low side gauge on a manifold.
20 Min Vac- sounds deep- well deeper than 10 min that is
we had a job this week with contamination, took about 12 hours of vacuuming plus several oil changes. Only a micron gauge will tell you if you've gotten the system down, time or a compound gauge says nothing.
Sounds like a job for our old friend Mr. R11
Alot of good points brought up. A 20 min DEEP vaccumm. WOW, thats deep, for 410.......UHHHHHHHH.
Also, has anyone seen the demo of how much moisture 410 pulls. The 410 refrigerant should have been recovered and new installed. Remember, it HAD a leak, which means the system was open.
I was the only Goodman distributor to sell 410 in the market 4 months ago. Most guys do not know what they are doing, one person will get certified, then they can buy it. They use there same gauges for 22 then hook it right to 410. Scarry thought.