Something has gone quite wrong with my 8kW Daikin today!

Hardware Heatpump
226

So, this thread has gone into areas outside my original problem, which is fine, and has been useful.

My original problem has not reared its head for some time with me which is good news.

My heat pump is in a fairly exposed location, against one wall of the house but wide open at the sides and the front.

Now that the wind has died down it is running very steadily.

So maybe air flow (wind in this case) is an issue. It has certainly made the heat pump less efficient by the looks of it as now it is calm it is running really well even though the headline outside temperature is no higher.

I feel that it is all rather sensitive to the weather, wind (turbulance?), wind chill, and higher outdoor temperatures coupled with low flow temperatures.

I feel happier that I have some idea of what is going on and what to treat as normal behaviour.

227

I’m not so fortunate @matt-drummer. Mine has been erroring twice a day like this at 8pm today:

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At midnight last night I saw it starting to error and switched off heating using Onecta and immediately re-enabled heating. When the pump started up again, it was not in the error state:

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I’ve started a discussion with Octopus aftercare engineers about this and will report back when that conversation concludes.

Cheers, David.

2 Likes
228

So, the first time I have seen it on anything other than an 8kW although I’m not sure what this really is as the flow temperature increases, so maybe not the same issue?

This is @Chris_Hill 6kW in space heating and the run came to an end, so either @Chris_Hill shut it down or it did it itself?

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229

what day was this and what are you pacifically looking at

230

Hi Chris,

It was yesterday.

It looks odd but maybe not the same issue as I thought me and others have experienced.

Large increase in electricity and not enough heat for the consumption (shown by the plummeting COP)

231

do you think it also happened just after 23:30 also ?

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is you flow rate doing the same ?
i never turned anything off

zoomed in

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232

Hi Chris,

Something has made the compressor stop but the heating must still be on as the pump is running (it’s not cold enough to be frost protection)

So, I would assume the heat demand is satisfied?

And the change in flow temperature is requested by the Madoka/MMI?

It doesn’t look like the `fault’ me and others have experienced.

Not very efficient though.

I run fixed lwt, no wdc, no schedules, nothing. I haven’t seen this on mine, but I wouldn’t.

I also don’t recall seeing anything like that before.

I wonder what made the compressor stop?

233

yes the home went particularly warm the target temp is set to 22 but i think i have a maximum internal temp (modoka) of 23 set in the mmi

234

The temperature reported in the chart is steady so that must be in another location to the Madoka?

My temperature sensor is in an upstairs bedroom but my downstairs where the Madoka is located is about 2c higher.

The Madoka sets the maximum, if you set 22c it will go to 23.5c and then turn the heating off.

And then not come on again until 21.5c.

Does your house cool that quickly? The heating starts again in 25 minutes.

Mine doesn’t.

You must also have your pump set to run continuously?

235

the temp is the modoka temp , the drop does look a bit dramatic than normal, but it is possible the garage door was open

if the heating stopped the blue led goes off and this can have a effect on the reported temp , i always notice this (crap design )

im not sure what the pump is set to but will take a look

236

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Pump is set to request

Wouldent the pump run on if the heat stopped for a set period ?
sorry for bad pic

237

The room set pump range is 18 to 23

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But the main zone range is 18 to 40 in installer setting

238

I don’t know Chris.

The compressor has stopped but the pump is running at 19lpm.

The Madoka has a 2c hysteresis but it only took 25 minutes for the compressor to come back on with no apparent loss in house temperature.

In any case, I saw and just thought it looked quite dramatic. It doesn’t look like a particularly controlled way for it to have decided to stop heating, and it has done the same at 23.30 as you mention.

1 Like
239

I don’t remember what those settings are.

It has been a long time since I have looked.

Are you sure one of those isn’t related to the outside temperature?

I know there is one temperature setting in the MMI that won’t allow the heat pump to space heat once the outside temperature reaches what you have set.

240

no i dont think so , as it was only 11.5 degrees outside and it has run without issues in the past above these temps

if you can remember where this setting is i can check

the day before the outside temps were over 12.5 and no sign of this happening

241

I wasn’t suggesting that the compressor stopped because it was 23c outside, it clearly wasn’t, I’m just not sure those settings are anything to do with internal temperature.

Is your Madoka and Onecta app restricted to no more than 23c indoors?

The pump was running continuously at 19lpm and the house doesn’t appear to have got any cooler, so I wonder why the compressor started again?

242

yes the max indoor temp @the modoka is 23 degrees (indoor)

ive just been back in my history and found this one and the pump stopped
on the 14th december

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outside temp only 7 degrees
and internal temp only 22

243

14 December, you turned the heating off I assume?

Yesterday, the heating was still on which is why the pump was running, but something stopped the compressor.

Maybe your MMI setting of 23c does something different.

Maybe that gives a smaller hysteresis on room temperature than the Madoka normally does.

So, set 23c (or whatever) in the MMI and the the compressor will go off at 23c and come back on when it’s under 23c (more or less)?

1 Like
244

I can’t remember turning it off , but I couldn’t be 100% sure

245

This makes sense to me ,