I like Daikin and Panasonic mate. I’m more familiar with Daikin but I like Panasonic after sales support way better. If it’s a ducted, I like Daikin because you can dismantle the indoor units whereas a lot of other brands you can’t.

@@maracservices ok cheers Mitch I’ll look into Panasonic and daikin

U0 fault means the Suction Pipe Temperature is too high. So if the Suction Pipe Thermistor is faulty it can trigger a U0 fault even if there is enough refrigerant. These things don’t have LP switches anymore. They just go off that one thermistor.

I used my Fluke multimeter to check the ohms of the EEV coil.

@@maracservices how do read through pins of the cable to the coil? Does the D checker also tell you if the eev is working?

@@guillermomera4153 the service tool tells you the pulse of the EV. So you know if it should be opening or closing. When I want to check the valve. I use a magnet. When I want to check the coil, I test the ohms of the pins on the plug that goes into the PCB. You can get the correct ohm readings from Daikin app.

So to clarify, I test the plug on the coil (not the PCB). Just to be clear. Thanks

@@maracservices what does testing the valve with a magnet involve?

No, you can gas it up when the system is off.

If you’re 100% sure the refrigerant charge is correct (you reclaimed all the existing gas in recovery mode and weighed the exact amount specified back in) then I would definitely be testing the Electronic Expansion Valve to make sure it works. I’d also be testing the low pressure transducer and thermistors. One of those things is causing the issue. If all those things are working fine, then the only other thing I can think of is there is a blockage in the lineset. Good luck!

thank u brother

It’s a tough one because the leak could legitimately be in the lineset and nothing to do with the Daikin unit. In that case, the U0 code is justifiable because the unit is just protecting itself. If it is Daikin, they should repair under warranty. Maybe try Toshiba, I heard they give 7 year warrant now. I’d definitely pressure test the lineset before installing the new unit though.

@@maracservices Cheers. Plan is to throw out the lines snd have a completely new install performed. Luckily its just about back to back so no big deal. Where ever the leak is its very small, ive gone over everything with soap spray and seen no bubbles including inside the roof on a 40c day and sprayed the flare nut connections on the inside unit too 😎

@@MMWA-DAVE just out of curiosity, did you increase the pressure within the system before looking for the leak with bubbles? In regards to Mitsubishi Heavy Industries, iv only ever installed a few of them before and they all worked well.

@@maracservices Nah, it was just running in normal operation mode. I dont have any dry nitrogen. BTW, my ac on the job experience totals about 3 months when 17 then quit and moved into IT. I couldn’t handle the roof spaces in summer. I never got an arc license, but still tinker with old car aircon systems, rebuilding, vacuuming and charging with hychill. For us non licensed plebs this stuff works great, havent had a single rebuilt system leak yet.

@@maracservices just to clarify, the daikin was professionally installed, not by me.

To be honest mate, I’m yet to go back to that job. I’ll definitely be going back, I’m just waiting on them to get back from holidays. Interestingly the system hasn’t missed a beat since (so it’s obviously a slow leak). I’m due to go back there this week or next to sort it out. I’ll be taking my leak detector this time.

@@maracservices we've got a daikin multi split system in an apartment that from time to time shows U0. Evidently there is a leak but have not been able to locate it. Can you do some magic?

@@yuhaogu4744 Does the unit blow nice cold air when it works? The reason I ask is, if the fault only happens every so often, then it sounds to me like it’s more likely to be a faulty thermistor or faulty pressure sensor as opposed to a refrigerant leak.

@@maracservices it's been an issue for a number of years. U0, light flashing, tested as low refrigerant, add some more, back to working until it doesn't in a few months. Also heating seems to always work but not cooling. Tested as having an unlocated leak somewhere...one more reason for people to steer clear of apartments.

@@yuhaogu4744 if the outdoor unit is located a long way away from the indoor unit (for example, outdoor unit being located on the roof of apartment building), then the only way to approach this in my opinion is to pressure test the system in three different sections. Not as one. So for example, pressure test the outdoor unit only. Pressure test the indoor only. Pressure test the lineset only. That way you will identify if the leak is in the indoor unit, outdoor unit or lineset. This way you can at least have a chance of finding it.