Fujitsu green flashing light.

Hi, I have a Fujitsu inverter heat pump. The numbers are AOT12LFBC & AST12LSBCW.
The heat pump stops heating and the green timer light flashes continuously. Only powering off will get the unit heating again. It appears to happen when outside temperatures are cold and damp. The outdoor unit ices up, then it goes into a defrost mode with red power light flashing. It will go into green flashing light mode before or during restart.
I tried reducing room temperature setting to 21°C (70°f)and it may have helped but today with outdoor temperatures about 7 -8°C (44°f - 46°f) it went into green light flash mode twice. ( It was powered off in between). Looking at the outdoor unit, it freezes at the bottom of the radiator.
Any tips appreciated. Anything I can do to improve outdoor unit from freeze-ups?
Please help. Thanks.

Read this post and follow the link!
The advise therein may help?
http://www.refrigeration-engineer.co...su+Fault+codes

Grizzly

Quote:

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Originally Posted by Grizzly

Read this post and follow the link!
The advise therein may help?
http://www.refrigeration-engineer.co...su+Fault+codes

Grizzly

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Grizzly, thanks. I browsed the error codes however my model isn't listed. I suppose codes could be the same?? Now I need to wait for it to trip into error mode again, then count flashes/blinks. I regret not recording or videoing it earlier.

Hi Tbird.
Hopefully the attached may help further?
Grizzly


Attachment 13799

Grizzly, thanks. The outside temperature today wasn't cold enough, nor was there any frost or fog so the heat pump didn't trip out into error mode. Weather forecast is showing frost temperatures for 4 - 5days next week so hopefully I can get the code information.
Yes, it appears that cold and/or damp triggers the error. Defrost seems to be working as water can be seen running out.
I have cleaned the outdoor unit coils however they weren't very dirty or blocked.
More details:
I bought the heat pump second hand 6 years ago and installed it. A used remote was obtained from a business however it isn't exactly the correct one. It does give beep responses to the buttons and display appears to work as expected. Frustratingly it errors when it's needed the most! Also annoying is it takes a long time to get going from 'power on', I guess it's programmed that way.
Thanks.

Hi,

Tried to attach the fault codes but they were too big so I've emailed that manual instead. Once the unit is flashing the code you can press the test run button on the remote to get a more specific pointer to the error.
If you power off the code is wiped and normal service is resumed (until next time!)

Not much you can do about preventing the outdoor unit freezing up other than lowering the setpoint and making sure there is the right amount of refrigerant in the system. Air off the indoor in heating should get to at least 40*C after 5 mins or so at those ambients.

Cheers,
Andy.

When defrosting the red operation light should flash on its own

Quote:

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Originally Posted by Tayters

Hi,
Tried to attach the fault codes but they were too big so I've emailed that manual instead. Once the unit is flashing the code you can press the test run button on the remote to get a more specific pointer to the error.
If you power off the code is wiped and normal service is resumed (until next time!)
Not much you can do about preventing the outdoor unit freezing up other than lowering the setpoint and making sure there is the right amount of refrigerant in the system. Air off the indoor in heating should get to at least 40*C after 5 mins or so at those ambients.
Cheers, Andy.
When defrosting the red operation light should flash on its own

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Andy, thanks. Super good. Hopefully that is a close enough model match. The heat pump hasn't error'd since but there is 4 days of freezing temperatures forecast.. This must show up the fault with frost and subzero freezing..

http://i1188.photobucket.com/albums/...psskuwtrxs.jpg

I confirm the red operation light does flash when defrosting. So that part is working as it should.

I had another look and clean up of the outdoor unit. There was a sensor at the top of the coil attached to the grill. I cleaned cobwebs, etc from it. Somehow I don't see the fix being this simple. Actually the heat pump has been going very well the last few days but then again it hasn't had the cold with damp conditions that I associate with the error.

I had a moment of excitement when I got out the original remote control. I shelved it 6 years ago because it didn't work. Nothing showing on the screen, etc. I put batteries in it and it worked for half an hour or so. Now it's dead again.
Pictured are my remotes available. Sorry about flash glare...
Right: replacement working remote. Center: original remote that came with heat pump. Left: another remote I had hoped would work be never did.
The boards inside the 2 Fuji style remotes are slightly different. I had thought maybe I could swap the LCD display but then thought the better of the idea. At least I have one that works. Fiddling might give me two that don't work. Then there might not be much to gain as far as functionality goes. Not sure..

What I did discover was the Start/Stop does not work on the replacement remote as the original Fuji. The extra button is for coil dry. The hope is the replacement will be good enough to give me the test function with needed fault details.

http://i1188.photobucket.com/albums/...psftyil5rx.jpg

OK, the heat pump (set at 23°C) error'd this afternoon when outdoor temperature was 8 - 9°C. I video'd the LED flashes:
http://vid1188.photobucket.com/album...psmueurcdn.mp4
I see it as 7 blinks for operation (red) & about 3 - 4 per second for timer (green). This appears to equate to: Refrigerant cycle error. I could not get the test button to work for more info. However the permanent stop error points to:" temperature protection, discharge temperature is 110°C, operated 2 times".

I restarted it and reduced the work load to 20°C and it has been running for a couple of hours without issue.

Right, so now I'm thinking perhaps the refrigerant is low. The fact it still goes means it must have at least some gas left. Could there be a leak or was it never filled correctly 6 years ago?
How to proceed?
Thanks.

If it's only been doing it recently I'd take out the charge and do a PLT

Quote:

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Originally Posted by Deano240

If it's only been doing it recently I'd take out the charge and do a PLT

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I had a tech come and inspect. It looked like a small leak at the pipe flares. It must be small because it lasted 6 years!
Anyway he re-flared the connections at the outside unit and regassed the system. He was onsite for 70min and cost $150.
It seems to be going very well but the real test will be over the weekend with -1°C frost forecast. Anyway looking promising at this moment.

BTW, the tech comments: the compressor was sounding good. There was 50°C at the indoor unit. Avoid running low on refrigerant! He was confident enough to suggest repair and regas over replacement despite the age.

Update. After running the heat pump for some days now, there is a marked improvement in performance. It starts up much quicker as well. There is some frosts forecast so we'll see how it performs.