Leak on system??

[N.Lewis]

Mornin guy's.
Got an odd one here, called to a daikin split fault, unit tripped out, put guages on showing zero pressures (leak yes!). Pressure tested 150psi, no leaks found, increased to 200psi, no leaks found, left ofn in over night, next morn holding spot on, vaced sys for approx 4hrs, turned vac off monitored for over an hour held perfectly, re-charged unit to manufacturers recomended charge, unit running nicely (this was friday), checked this morning it's lost a fraction of it's charge but still running:(
Any ideas!!!!!!!

[The Viking]

You haven't told us what model you are working on...

If I say that it's an inverted unit, size 100 or 125, would I be right?

[The Viking]

If I am right:

Daikin had a whole bunch of them where they got one of the holes in the condensor coil's frame slightly out of alignment...the frame end up rubbing a hole in the pipe that goes through that hole..

Fatherless thing to find as more often than not it's only leaking when the condensor is hot.

Where you have to look is the third row up, inside lot, by the compressor.
It is hard to find these leaks but if you take the covers off and undo the bottom screw holding the coil frame, then you are able to force the coil frame backwards and expose the leak. In this position it will leak even with a cold coil.

(We replaced quite a lot of these coils, 3 figures for sure and Daikin is aware of the problem)


Good luck

[N.Lewis]

Thank's viking, just goes to show how good this site is, i would never have figured that one out without being able to tap into other engineers experiance, i'll see if i can locate leak and rectify, and or recomend replacement condensor.
Again many thank's.:D

[declan simmonds]

hello n.lewis
ive had the same fault as viking said but my condenser coil only leaked when it was running ive had to replace about 15 condenser coils on daikins over the last year. there not to difficult to replace but if you decide to repair the coil you will just end up chasing the leak up and down the coil so just replace it outright its not worth the hassle. obviously daikin has some quailty control issues but having said that there still good. compared to the others. ive never had many problems with daikin units direct from japan always belgium.

[N.Lewis]

Hi declan, i think that's going to be the way to go, luckaly there are two identical units next to it, one of which is not in use any longer not due to any faults, so i will just swap that one over.
How you finding stevenage!! i'v got a few friends over there...:D

[declan simmonds]

hello n lewis well you sound like you got it sorted, as for stevenage everyone gives it a bad wrap but i think its ok a bit wild on sat nights, but im currently in madrid coming back soon as i cant find a good job here. plus the pay is terrible well stevenage here i come watch out

[philjd26]

sup,
make sure your shreader is ok maybe when you have a line connected its good but might be slighty leaking when off.

rgrd phil

[stuartwking]

Hi viking, Those Daikin coils are a real pain!!, I have found loads of them leaking!!!, The company now keep a stock of RZP and RZQ cond coils,. Daikin do say they have sorted the problem so fingers crossed,..

[The Viking]

Hi viking, Those Daikin coils are a real pain!!, I have found loads of them leaking!!!, The company now keep a stock of RZP and RZQ cond coils,. Daikin do say they have sorted the problem so fingers crossed,..

Yes, we also up in 3 figures of changing these...
But touch wood, none of the new coils has leaked...

[stuartwking]

One of mine did!, Brand new r410a split installed for 3 months,. I think the model was a RZQ100D, anyway it is the new RZQ with a different condenser coil.Not good..

[thebigcheese]

if its r407 should u not use helium as the molecules are smaller?????

[stuartwking]

Hi Bigcheese. Do you use Helium to pressure test r407c?,, If i did i would just use it all on myself!,,. Never herd of using it before.

[Brian_UK]

Just a thought, is 200psi enough to perform a decent pressure test ?

[stuartwking]

Good point Brian,,.. Surely you should be pressure testing to at least the max operating pressure!, unless he is just leak tracing which i guess could be done with a lower standing pressure..,

[thebigcheese]

well have used it twice to pressure tezst when we couldnt find a leak 1 was a freezer on r404 and then a carrier satilite on 407c, was told to do this by the people that suplies are refrigerant ??????

[IceMan08]

sup,
make sure your shreader is ok maybe when you have a line connected its good but might be slighty leaking when off.

rgrd phil

But surely all shraeder caps are replaced afer valve use, right?

[IceMan08]

daikin also had an issue with the vrv,s but it was the inbuilt gauges, we had 7 out of 40 with this, and only found it by accident!

[gk1139]

Whats it running on? 200psi on a R410a system is totally pointless and a waste of time! Must always strength test at 1.6 times mwp for 15 mins and leak test at 1.1 mwp for as long as poss!

[dhananjaylagwan]

Well i am just attaching pictures of cooling coils where we detected pinholes. We started the D-X system 2 months ago and then we noticed that the pressure was dropping continously.

After using a gas detector we were able to locate small pinholes on the tubes of the coil. They were in the 2 nd row.

After investigation it was found that the during the transportation of coils the coil manufacturer had kept the holding pressure in the coil at 350 psi [nitrogen]. Thus when the coils were being transported [The journey was of 5 days] the pinholes were developed on account of impact and increase in pressure cause of vibration.

We had to replace the entire lot of cooling coils because of this.

[nike123]

After investigation it was found that the during the transportation of coils the coil manufacturer had kept the holding pressure in the coil at 350 psi [nitrogen]. Thus when the coils were being transported [The journey was of 5 days] the pinholes were developed on account of impact and increase in pressure cause of vibration.



I think that that theory don't hold water.
It is not liquid inside the coil to directly transfer vibration to coil walls.
If it is on same place on all coils, than it is more likely that forming tool damaged the tube.

[Makeit go Right]

Wow. This leaky equipment is quite a flap.

All of those large 10kW + 12kW condensers have at least 3kgs of R410a gas in them, then the top-up gas when piped up in a system, and after a few weeks (or sooner) that gas was all wafting into the atmosphere.

To just keep sending out the equipment, knowing it is faulty - presumably after the first few reports Daikin have NOT stopped further deliveries of the same batch(es) or put out a recall/warranty check of other kit sent out in the same batch(es), since one of the above engineers has replaced more than 100 leaky coils, and others replaced 10s and 20s of them.

It is all very well keeping a stack of replacement coils ready to send out to the next warranty call, but where is the Daikin responsibility for the gas discharge to atmosphere? Where is their quality control? As soon as the first few reports came in Daikin should have been ripping open the boxes to check and make sure the ready-to-send kit was all 100% before letting it go out. That does not seem to have been the case here, not if there are 100s of coils (at least) having to be replaced.

And for the unchecked equipment that went out, Daikin should have their own engineers hunting down all of the suspected equipment and verifying on site that there is no threat of leak on the equipment. And for coils that are suspect/badly constructed and likely to cause a refrigerant gas leak, they should be replaced BEFORE they leak refrigerant gas into the atmosphere.

And this is not just a matter of damage to their brand name, this is a legal matter surely? If they are knowingly dispatching kit that is suspected of leaks, which will subsequently release hundreds of kgs of refrigerant gas - a controlled waste - into the atmosphere...........well, it doesn't bear thinking about.

[The Viking]

Ahm MgR,

In the case of the Daikin coils, the units were actually running at least 6 months (24/7 in our cases) before they lost the charge with some of them still running on the original coil.

As soon as Daikin got wise to the problem they changed the production jig.
(you might have noticed that for a couple of months about 2 years ago you couldn't get hold of a 100 or 125 inverted outdoor unit? that's when it happened...)

[Makeit go Right]

Ah, are you saying they already did the necessary on coils distributed, and it is not possible to buy one of these leaky things nowadays.

Well, okay, then.

[beezerlogic]

Daikin coils, have had in last three years about 20 coil replaces to rzq125 condensers.Have repaired about 20 coils by cutting back the steel around the leak and cutting away damaged pipe and sleeving over.Not had one re fail yet.These coils are a pain and the leaks can be hard to detect.Usually to top of coil at rear above compressor but have had them at the coil bottom behind compressor,at 550psig it can still be like cuckoo spit.Remember if you order a coil the serial numbers changed at say 2000000,they will send you the wrong coil,it wont be a 90degree coil but about 100degree and it wont fit in the unit.

[beezerlogic]

use argon then, good leak testing not as many chip monks

[paddyaircon]

i had a 407c 125 with same fault-

[still learning]

regarding leaky dakin coils, have been alerted to these due to oil dripping out the bottom of the unit, a little goes along way, and very hard to see the source.