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Numerous issues – 11kW Daikin Altherma 3

newhouse87 · 2023-03-16T04:32:58Z

HI, Just found this forum last night and some of the posters on here have better knowledge then i have found anywhere else. Don't understand alot of it yet but anyway i had 11kw daikin altherma3 low temp split installed last February and moved into the newbuild in June. Only since winter came i have noticed many issues. For past 3 months some rooms were not heating at all but in the last 2 weeks i have figured out stats were wired to wrong ufh loops, have that sorted now thankfully. Installer left me no paperwork and told me nothing about system. Im still thinking its not as efficient as it should be. Some rooms take up to5-7 hours to get up to 21degree setpoint from say19degrees. Only from reading this forum i think my dhw schedule is bit inefficient. DHW 7am 50deg,2pm 50deg, once a week at5am 60deglegionella cycle. All schedules are 2hours long i think. Reheat set point is at 45 so from reading here im thinking that's too high and may override my ufh flow too much. Im on weather dependent mode but yesterday was 11 degrees and my lwt was 32. Is that bit cold and maybe why my ufh slow? Also noticed my copper flow pipe from unit gets hot but i could go back into room 10mins later and its alot cooler, any reason for this? Apologies about all the questions but i had extreme bills in nov/dec and want to figure this out and this forum seems by far the most knowledagble. Using 70kwhs a day on cold days in a well insulated 2600sq ft bungalow seems bit much. Getting some big spikes especially at night time/early morning. Thanks again.

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newhouse87

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Topic starter 11/04/2023 8:15 pm

@derek-m think there is a plate heat exchanger in it.

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newhouse87

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Topic starter 11/04/2023 8:21 pm

should i give it more time or is this test telling me its not buh issue so?

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Derek M

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11/04/2023 8:29 pm

@newhouse87

There will be a plate heat exchanger inside the outdoor unit, but that is between the refrigerant gas and the water. You could have another PHE indoors between the primary water and the secondary water.

If the problem has not reappeared by the time you go to bed, then it may not be a BUH problem. I'm afraid my eyesight is not good enough to see what is happening from here.

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newhouse87

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Topic starter 11/04/2023 8:31 pm

@derek-m i have a phe temp reading aswell, is that heat exchanger indoor unit so. Ha, no problem, you have been v helpful, my plumber wouldn't have a clue. i emailed daikin a few hours ago so hopefully they will get back to me. PHE temp generally same or near to lwt. Ill update with what is running next time it happens.

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newhouse87

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Topic starter 12/04/2023 9:40 am

so it happened again at 11:30last night, l have attached pics of what was running and temps. Have other pics of other settings

but not sure if relevant.

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newhouse87

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Topic starter 12/04/2023 9:43 am

pics not v clear but if ye have any questions whats what il know. what does sh for compressor and shc for 3 way valve mean?

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Derek M

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12/04/2023 9:45 am

@newhouse87

Please post all information, since it would appear the BUH's were not the cause.

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Transparent

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12/04/2023 9:51 am

Given that Daikin are an international company, I think the LCD display isn't using British nomenclature.

I think the 3-way valve reference to SHC is "Space Heating & Cooling".
Ie it's sending the flow to the UFH or Radiators, rather than the Domestic Hot Water route.

Save energy... recycle electrons!

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newhouse87

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Topic starter 12/04/2023 10:14 am

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newhouse87

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Topic starter 12/04/2023 10:15 am

@transparent and now to figure out why, What is that cycling thing ye talk about, presume its not that?

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Transparent

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12/04/2023 10:18 am

I'm not the best person to answer that @newhouse87

I'm not a heat pump specialist.
I work with embedded controllers, sensors, feedback systems and the suchlike.

My understanding of heat pump cycling has come from analysing data retrieved from substation transformers.
So I've understood the need to to reduce on/off cycling, but not from the usual viewpoint!

This post was modified 3 years ago by Transparent

Save energy... recycle electrons!

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Derek M

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12/04/2023 10:30 am

@newhouse87

There is nothing shown on the displays supplied that would appear to be using lots of power. What was the power consumption at the time and how is it being measured?

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