Ämne: mitsubishi ecodan

[söder]

Har en ny installerad luft vatten pump av märket mitsubishi ecodan och undrar om det finns nån med liknande problem som jag har?
Huset är 270 kvm m golv värme i källaren ca 90 kvm ,vid ca 0 grader så orkar den inte värma hela huset+varm vatten.
Har hört av andra att mitsubishi har problem med kretskorten och att den därför får fel signaler?
Finns det nån som har liknande problem?
mvh söder

[ace]

Hmm..orkar inte   
menar du att maskinen plus tillsats går konstant utan att få upp temp.... kan det vara möjligt   

det är inte bara fel kurva ??

ACE

[söder]

Tillsats elen slår aldrig till tex när den värmer radiator så slår alla steg på och det går hyffsat fort upp men stannar vid ca 33 grader fastän börvärdet är högre har provat att ändra alla variabler men utan resultat,när den sedan slår över till vv så slår den bara på steg 3 1o2 är av och det tar då evigheter för vv att bli varmt.Om jag har ett läckage av köldmedium skulle det kunna förklara saken?
tacksam för svar teorier ideer
mvh söder

[aryl]

Sorry I am writing in english. I have similar kind of problem: electrical heat never goes on, neither 3 kW or 9 kW (=stage 1 & 2).

Everything went fine down to -20 C (both heating the floors and water) but now when we have here down to -26 C it cannot provide enough energy any more solely with compressor. There is this setting "time before electrical heat" but it does not seem to have any effect. Furthermore I can't understand why it powers down to compressor step 3 when making warm water. It takes time without electric heat to reach the set value and all this time is out from radiator heat.

The brochure claims that this unit can cleverly turn electric heat on when needed. It just does not happen. For me it sounds like a serious bug in control SW.
 
I would imagine that "extra hot water" would turn the electric heat on but it doesn't.
Another bug: hot water peak seems not to work either. Maybe this is related to the fact it can't take the electric to .

The only way I have been able to set electric heaters on is to run this device in manual mode. But then there is this restriction that it be in manual mode only 60 minutes. Let me know if any of you know the way how to force electric heaters on.

Something about my setup: this is ecodan zubadan model, control modified by swedish people. My house is located in northern Finland, 320 m2 and 1250 m3.

[tro]

Hello Aryl,

Noticed the same problem myself yesterday. It seems that the control software is full of errors. My ecodan went into a loop yesterday, when making ww with compressor step 3 only and outside temp -24C ecodan could only heat up the ww to +48C, stop value for the ww is set to 50.5C. Furthermore it ignored the heating of the house totally. I tried to set the compressor shutoff temp to -10C in order to get the ecodan to use electric heaters but no luck so it seems that the compressor will never shutdown nomatter what the outside temp is and it won't use the 3/9 kW electrical heaters. However finally i managed the ecodan to turn on stage 1 electrical heaters along with the compressor running at all stages by setting the "time before electrical heat to 0 min". And the only way i found out to get the ecodan out of the loop was to lower the ww stop temp to +45C then it started heating the house again. I was happy with my ecodan until yesterday but now when changing and testing different parameters in amb.temp -24C it seems like many of the parameters are ignored by the controlsoftware and it is really badly made. Hopefully the new improved software will be released shortly.

[aryl]

hi,

my installer found out that there is a new SW release available for my unit (build June-2008). I hope it solves this problem for good.

My recommendation for you Tro is that lower the setting value for WW (let's say to 47 C) because making WW is the first priority for this device. Also set the maximum time for making the warm water down to 30 minutes or so since then it has more time for heating the house. Then you could run some time in manual mode both for WW and radiators (especially if you need WW for sauna or shower), it is only 1 user setting under manual mode controls to set the valve position. By doing this way I was able to manage quite well in -24 C.

One thing came into my mind is that most probably this device heat curve is set for outgoing water temperature and not for the coming: it was claiming that there is no need for radiator heat (heat curve request value was 32 C when returning water temperature was about 20 C). I don't know if that is really true when manuals tell otherwise and there is no sensor for outgoing water temperature or at least it is not shown. Nevertheless when I raised heat curve values with few grades it started to request heat and providing it. I guess this was the original reason why my house got cool: no request, no heat.

Another bug I noticed: the user setting to switch off can be down to -25 C. It continued working still even with -27 C.

[tro]

Yes i got the same info from my installer new sw on the way so hopefully this will fix all the minor and major bugs.

What range do you use for the ww, start=42C stop=47C?

I will set my parameters back to normal again today as the outside temp is "only" around -15 today, in order to avoid the loop i have now been running on settings ww start 42 stop 45 and heating of ww to 15 min. With these settings i have managed to keep the house warm (around +21,5C) and the ammount of ww has been enough running on compressor only with outside temp < -20C. Concidering that the house is rather old (built 1974 and 280m2) and using old high temp radiators i must say that the zubudan seems to be rather efficient as it still can keep the inside temp on 21.5C with compressor only.

The heatcurve was explained to me like this. If you are running radiators the heatcurve is set for the returnwater and for floorheating you are setting the outgoing temp. However measuring the outgoing temp would require an additional sensor as i have also a sensor measuring the returnwater only.
However it seems that we both had the same problem with the curve, when mine went crazy it also told me that no heating is required so it didn't give any heat :-).

Noticed the same bug also, i tried to force my to use the electric heaters and set the outside cutoff compressortemp to -10C when the outside temp was in fact -24C and it didn't stop so....

Anyhow lets hope the new sw release will take care of all these problems then i will be happy because becides from the loop the device has been working good and the consumtion of kWhs' is not too bad either.

[aryl]

that's correct, I use the range 42-47 C but when weather gets easier I keep it 42-48 C and also increase the time for WW, today it is 40 minutes.

I am actually having floors heated but still I have to use radiator side for settings. I don't know why it is set up like that.
My understanding is that heating the normal radiators is much more challenging target for pumps and COP suffers when higher temperatures must be achieved. So your case sounds really good after all and proves there is a lot of potential in this mitsubishi.

Anyway, thanks to this forum and the information I have received (also through e-mail). It seems that in Sweden energy saving is on better level than here in Finland.