Poor DHW COP on an 8.5kW EcoDan?

Hardware Heatpump
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Legionella_cycle
Legionella_cycle3840Ɨ1984 336 KB

Still getting low COPs, some yesterday DHW COPs from the MQTT Bridge as low as 1.3, highest 2.16, averaging 1.64.

First Legionella with Bridge attached from last night, started 0300, heated with pump until approximately 0317, flow temp reached 47.5 C going up from approximately 32 C. Immersion switched on for approximately 43 minutes until 0400 where the DHW temperature reached 51.5 C, Ecodan yesterday DHW COP of 0.87!

Ordered thermal paste, insulation and power monitoring, surprised at how poorly it is performing.

Heating COPs from the Ecodan numbers are averaging 2.57 with sub 40 flow temps and generally mild outside temperatures.

Flow rate and Compressor lines going up to the right is just continuity of data, next values are post 0400 when heating kicks in. DHW is in Eco, both pumps are on 4 setting in FTC controller, Quiet mode enabled.

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The actual performance of the Ecodan is likely to be not nearly as bad as it looks here, which should improve as soon as those thermal sensors get fitted properly.

1 Like
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If the immersion heater size is set in the service menu then it shouldnā€™t drop below 1.0

Is auto adapt minimum flow temperature reduced to 25 in the service menu too or the default (35 I think)?

Any way to double check the calibration of the flow and return sensors?

SD card fitted and showing healthy for the AA data?

I assume if itā€™s running at 20-25Hz on heating then computed input power will be around 0.55kW and itā€™s the delivered heat meaning the low CoP

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Iā€™ll check the immersion setting and minimum flow temperature when I am back later today.

Iā€™ve been running it in Heating Flow at about 34 to 37 C for periods of several hours, matching most demand to Cosy tariff low periods, the compressor frequency rarely goes down as far as low 20s. Iā€™ll try going back to AutoAdapt.

Do you need to pop out the SD card to read the AA data?

Iā€™ll probably invest in the OEM H2 kit next year to validate the temperature readings.

The lower left pump has a button on it, which by the look of the symbols allows speed settings and radiator/under floor modes to be changes, I assume the FTC is able to control those setting and it isnā€™t a simple on/off.

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34 to 37 flow temp might be 32 to 40hz

Input maybe ~1kW at the lower freq, so hoping for an output ~4kW

I think the Grundfos UPS3 pump can be used with the options for Constant Curve (one-zone), Proportional Pressure (2 zone) or Constant Pressure (UFH)

Only constant curve can have PWM the LED on the left, green is flashing and all others static if in use (and the FTC supports it)

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Immersion was on 0, I set it to 2.

Minimum temperature is 30 C.

Leftmost LED on pump lit when heating on.

P1 (Flow temp sensor fault?) error occurred twice within 5 minutes, 5 days ago after it had been heating for just over 2 hours.

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Any improvement to report?

And what FTC software version is the unit running out of interest?

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FTC Software version 19.00

No improvement but a lot of what I ordered still hasnā€™t arrived.

Iā€™ve switched DHW back to Normal from Eco and switched off quite mode, heating now with AutoAdapt/Heating Temperature, impressed with how it manages to maintain temperature when the stat is in the right place.

DHW COP yesterday 1.36 (best since 29th December), Heating 1.69 (Outside temp between 1 and 5 degrees), total house demand 42 kWh, Ecodan consumption estimated 31.38 kWH, production 48.99 kWh.

Seems to be 50% running cost compared with previous, feels like COP is underestimating actual performance.