Mini-spliy makes "discharge of gas" and much coolder air every 10 or 15 minutes

[LChaminés]

Hi again,
We were called back for an assistance on a new mini-split that was mounted on a pre-existing circuit (not the right name, there were already tubes of cooper, and wires, and da-da-da) and the client said that in the first 3 or 4 times everything worked great but know he can hear every 10 or 15 minutes a sound that looks like a discharge of gasr410a (or abnormal movement) and he feels that the air gets much cooler for a brief period of time.

We are going there next week to see the problem and we think that it might be a capilar (don´t know if it's the right word) that got dirt on it (we used nitrogen to clean the tubes but we didn't left it for a long period of time, more like a blow of nitrogen), it could be a defect on the machine but since it worked fine for 2 or 3 times that's kind of ruled out.

Anyone has any ideas about this or a similar experience?

Any help would be appreciated, thanks in advance.

[The Viking]

Did you do a pressure test and take a proper vacuum on the system before you started it up?

:cool:

[LChaminés]

Did you do a pressure test and take a proper vacuum on the system before you started it up?

:cool:

We didn't do the pressure test correctly because one of our hoses of the manifold was damaged (we didn't notice that it wasn´t aplying pressure to the valve in the exterior unit and because of this we also didn´t do the vacuum correctly (we only noticed this defect on the next instalation).
So once again, it´s probably dust in the pipes wich we probably are gonna regreat alot because we'll probably gonna have to pay for a new one.

[The Viking]

Mmmm...
There is a lesson to be learnt in there somewhere :)

However, doubt you will have to replace the machine, start with reclaiming the gas -> pressure testing -> Good vacuum -> fresh refrigerant and then see how it runs.

But it would have been cheaper getting it right in the first place.

Also, when you ask for our advice... Please give us all information you got in the first post, it makes the procedure so much quicker than if we have to post back and fro just to establish what you already knows.
(And, I for one comes to much better conclusions when I got all the relevant information)


:cool:

[LChaminés]

Mmmm...
There is a lesson to be learnt in there somewhere :)

However, doubt you will have to replace the machine, start with reclaiming the gas -> pressure testing -> Good vacuum -> fresh refrigerant and then see how it runs.

But it would have been cheaper getting it right in the first place.

Also, when you ask for our advice... Please give us all information you got in the first post, it makes the procedure so much quicker than if we have to post back and fro just to establish what you already knows.
(And, I for one comes to much better conclusions when I got all the relevant information)


:cool:

You are right and thanks for the help, I should have talked about the vacuum, we're going to the clients house wendnesday and I'll report back what we found.

[LChaminés]

I'm kicking myself in the head for this one, so the problem aparently (it's solved but let's wait some days and see, was a bad flare on the exterior unit that leaked all the r410a, the "discharge sound" I suppose it was some leftovers of gas that gathered and then got released from time to time (the client said he hadn't heard nothing strange ina couple of days (no gass..), what the client didn't noticed was that the Air conditioner wasn't making any cold, only the fans were on but he thought that was normal.
New flares, vaccum and a recharge of r410a by weight and it's working again, we didn't detect any other leaks, let's hope we don't drop the ball on this one again.
Minor note, there was (sometimes) a almost silent sound of movement (gass), o think it's normal since you couldn't almost hear it, but it got me thinking if we messed up on the charge (although I don't think so, we used factory recomendations, the only thing was that since we had to recharge 1,150Kg of r410a we started doing it with the machine turned off, than turned the machine on half-way for a few seconds (the idea was to drop the pressure a little), than completed the charge and finally we started the machine once again, is this a bad procedure???

Thanks for any help.