Defrost on a Daikin, what happens and why ??

[@MM-rk8rq]

Dobar video. Pozdrav iz Srbije🇷🇸

[@k03nsm33ts]

Great video! Thanks for the explanation. I got here because I have a Daikin Altherma 3 RF+W which I need to pump down (relocation of indoor unit) - but it does not have a documented pump down mode. I found a snippet of text in Daikin documentation for a completely different system that suggests forced defrost is the mode to be used when performing a pump down. Any advise?

[@FullyAirconditioned]

@@k03nsm33ts I haven’t had to pump one down, but run it in cooling (if units reverse cycle) or defrost (cooling cycle). There is probably a setting on the pc boars that could be set to put it into forced pump down, but I don’t have any documentation if it how it can be done. If gas has been added for the additional length of pipe you may only get it pumped down so far, then recover the remaining gas, weight the recovered gas it so you know how much to add. We would usually weight the recovery unit and gas bottle before and after recovering so we know how much to add. If its cold out side compared to inside the gas will migrate to the outdoor unit then just close off the valves and recover the remaining gas in the pipe work, you may need to put the unit into evacuation mode so it open up all the valves and allows the gas to migrate to the outdoor unit, this will only work if it’s colder that the indoor unit.

[@ΓΙΩΡΓΟΣΠΑΣΧΑΛΙΔΗΣ-ο9φ]

Thank you very much.... From Greece

[@FullyAirconditioned]

No worries mate 👍🏻

[@Harry_Bl44346]

Thanks for a very in depth video

[@alexanderkalashnikov9264]

Thanks for Video. very informative with a lot of details. So what should i do if it goes to defrost mode a lot in the short period of time. Tassie cold freezing up out heat pump?

[@FullyAirconditioned]

Hi, is the the coils freeze up like in the video, full coil covered in ice or just a part of the coil ? If it’s full coil, then maybe check sizing of system. If it’s part of the coil then there could be a problem and you will need a technician. To calculate if it’s under sized as a ruling thumb you should have about 130-170 watts per m2. This will vary depending on how well the house is insulated, ceiling heights ect. If it’s lower than this I would be worried about sizing of the system. Talk to some who works in the area and ask what they would size for a house like yours.

[@lanataylor4229]

Fantastic video. My unit goes into defrost mode at about 7am (unit is set for it to come on at 5:30am) …. But I’m in Sydney and it’s not even the middle of winter. I don’t know how it’s getting cold enough for this to happen? There’s no frost on my pool fence 😋

[@FullyAirconditioned]

Hi Lana, It doesn't frost over because of the frost outside its because the gas in the system is boiling at a lower temperature that the outside air temperature. If it's 8 degrees outside then the gas in the outdoor unit is boiling off at about 10 degrees below this, so @ -2, at this temp the coil will start to form ice and need to go through a defrost. it sounds about right starts at 5.30 and is defrosting at 7, this could possibly be its 2nd defrost for the morning. Start the system earlier, or keep it on a low temp overnight, we set outs to 17 degrees c, on cold nights it might come on once or twice. To heat up faster and avoid a defrost a larger system with more capacity would be required, capacity is king. Thanks Craig

[@lanataylor4229]

@@FullyAirconditioned you are a god send Craig !!! Thank you so much. What a legend 💪

[@fifis101]

Is there a manual force defrost function? Running my unit in cooling does work sometimes but if it's already cool inside it won't run. All the thermistors seem to be in the right value range. I have a technitian organised to come and check the gas level in my system but if it's not that then I'm out of options.

[@bradroesler7072]

I notice that when these Daikin's run for awhile in heat mode, they go into defrost, even with no ice on the outdoor coil. Why does this happen? Also, what tells the indoor fan to turn off before a defrost?

[@FullyAirconditioned]

There is so many inputs that put the Daikin unit into defrost but they’re definitely is a defrost that the system goes into Just to doublecheck It’s not frozen. I think from factory it is every four hours and on initial start-up. It sounds like a stupid thing to have, but unless you’ve seen a unit that doesn’t have this and within a week the outdoor unit is a block of ice because the unit may run, never run long enough to trigger a defrost on time and the accumulation of ice builds up.

[@abelramos8652]

Hi Craig! My US7 sometimes defrost when is not even -0 temperatures I take a look outside and there’s not frost … why this happens? Is faulty? Thanks

[@FullyAirconditioned]

All Daikins units will periodically go into a defrost just to check that the units not frozen, it sounds like a negative but when you’ve dealt with brands that don’t have this feature and the unit turns into a block of ice, it is a good feature to have in the system.

[@abelramos8652]

@@FullyAirconditioned thanks for the support as always!

[@bradroesler7072]

Off topic, but why does Daikin do a preheat cycle on the startup sequence in heat mode?

[@FullyAirconditioned]

It does that so its not blowing cool air on start up, the coil heats up to a set temp, then the fan cycles on. As the coil maintains a rising temp the fan keeps stepping up in speed until it reaches its set speed.

[@fifis101]

Some great information there. Nothing I don't already know though. What I'd like to know more about is the field setting to change the defrost settings. I was recommended to change the defrost start setting from "standard" to "quick start" but I think that's made things worse. I will change it back when I get home this afternoon but keen to hear if you have more to add on this? I think my unit is going into defrost but possibly not doing it for long enough to fully defrost the frost build up. It then goes back to heating which just turns the melted frost into solid ice, which is harder to melt next time and a vicious cycle starts.

[@FullyAirconditioned]

If it’s not fully defrosted, it could be sensor not reading the temp correctly, out a few degrees, finishing defrost early.

[@fifis101]

@@FullyAirconditioned I wasn't sure if the defrost worked on a set time arrangement or a temperature. Can you confirm that these Daikin units switch the defrost off once the temperature rises back to a certain value?

[@belikovXlove]

It gets SUPER loud while defrosting and my neighbor complains.. Please is there something that can be done - like picking a time for it to defrost so it is not at 10 PM or making it quieter overall - the DAIKIN is FTXC. Thank you very much in advance!

[@FullyAirconditioned]

Hi, I think most Daikin units have a noise reduction fiction but I am not sure with your particular model unit , as it’s not sold in Australia. If it has a quiet function I don’t know if it effect’s the defrost mode noise levels that much, but worth a try. If your outdoor unit looks like the ones in this video then I believe it would have I night quiet function. The function is usually set from the outdoor unit. It’s usually done with a binary code and LEDs lights indicating what you are setting. On the newer units there a quite mode that can be set from the wall controller. A Daikin services manual would have the details but I don’t have access to overseas models. It may be best to call your local Daikin dealer or Daikin them and ask them if a quiet mode can be set.

[@geralddroog1745]

Well presented

[@angelusnah]

Hey Craig - any opinions about why a system might initially start and the “induct temp” it’s hitting is about 42-44 pretty stable. It then goes into defrost mode after some time and when it starts up again it won’t hit induct temps higher than 33-35.

[@FullyAirconditioned]

Could be a number of things, best to check the pressure sensors and temperature sensors first, if they’re all good possibly look at correct gas charge.

[@angelusnah]

@@FullyAirconditioned thanks mate.

[@maxd4968]

Interesting my Daikin minsplit turns the compressor off completely before switching the reversing valve. I think most of them do that

[@FullyAirconditioned]

I have only seen them ramp the speed down (inverter compressor). The old fixed speed compressors would just switch the reversing valve, compressor at full speed, a violent change over. I guess ramping the compressor down could reduce fatigue of the pipe work, reducing leaks.

[@maxd4968]

@@FullyAirconditioned huh yeah mines a inverter from 2005 (FTXD60BVMA) and it definitely switches it completely off and then starts it up for the defrost

[@sselectricalmelbourne.2879]

Thanks for the video you have saved me a few times on site in the past. Keep up the good work. Steve.

[@FullyAirconditioned]

Thanks Steve 👍🏻

[@aus_aircon_ref_mech6671]

Another great video. I have to say the dedication you have to get up on a Saturday, during a cold Canberra morning to get this footage is awesome!

[@josephwalkerden8180]

Great Video. We could do with alot more knowledgeabe AC guys in the industry like steve. Too many cowboys.

[@paulkolbert1478]

Where did you purchase the Wi-Fi adapter? Nice video

[@FullyAirconditioned]

Daikin Australia

[@AzimUhamid]

So can we use hot water to defrost the outdoor unit?

[@FullyAirconditioned]

You could if you want, but it would have to be done during defrost mode, The system should just go through the defrost process and start heating once defrost is done. If it’s not handling the heating when it very cold out side then the system would most probably be under sized for the area it’s heating when it’s cold outside. A correctly sized systems will have enough heating capacity to heat the area and go through a defrost process. Under sized systems are very common unfortunately and give air conditioning a bad name for heating. When it’s cold outside there is less heat in the outside air, because there is less heat in the air for the air conditioning system to absorb the capacity of the system is reduced. I really comes back to the company that sized the system and have they sized it correctly.

[@AzimUhamid]

Thanks for the reply. true about the undersizing, I thought I was getting my system from experts, but I was wrong. When below 5*C, after turning on my system blows cold year...