@ngillam

Check the thermistor readings as detailed in the attached video.

If the controller is indicating -39C then check to see if the controller is correctly configured. Also check to see if the thermistor is wired to the correct connection.

@ngillam now you have access to the app at the bottom of the screen is a reports tab then press hourly temperature it will display the flow and return temps for the most recent hour. At the top of the screen will be the time press that and you can select any hour in the last 24 hours so you can see exactly when the heat pump was on and what temp it was running at.

As your system is running off 3rd party thermostats that -39C reading won’t matter it’s the temperature near to the controller unit.

@derek-m

Well there's the culprit I suppose, looks as though it's going to be a long term investigation, I'm heading aay for a few days.  Thanks for the tip.

@gary

Haven't scrutinised it yet, productive day sorting the shed.  Those readings look wrong though, looks a headache!

@ngillam that’s heating the hot water you can see the red line increasing at the same time check some of the other hours of the day when it was heating the house

Hello Gary,

Still struggling with this, seems we can't get the house cool enough, won't go below 22degs, if I alter the WC curve to its lowest temp (20degs) then I suffer cycling which I've seen on other threads.  It seems the house is really well insulated and we're just not losing the heat, the other half is getting a bit annoyed at the high temps.

Any suggestions?

Thanks,

Neil

At this time of year you will need to use your thermostats to limit overheating.  Are they heatmiser as well?  Now you have set the warm end of the curve you can set the thermostats to the max temp you want then the heat pump should shut off unless you have multiple zones in the UFH linked to numerous thermostats?

@gary This is my set up, I thought the idea was to let the heatmisers (in each room) run free?  Mine are at 35 degs but sit at about 22 degs.  my partner wants to open windows to cool the place off but that seems wasteful.  All underfloor heating is hard to control.

If you can’t control the house temp through the flow temps you will have  to have thermostats to stop the house getting hotter than required.

@gary By flow temps you mean those set via WC curve?  Just had a thought, all the trickle vents are closed on the windows!!

I think you said your set up was similar to mine Gary, can I ask your KWH for Oct?  heating and DH combined?

Thanks,

Neil.

Yes the flow temps in the WC curve you are running as cool as possible but that is still overheating the house so all you can do is turn it off when the house gets hot enough.

I don’t measure the heat pump consumption separately but I estimate it about 10kwh a day for water and heating in October.  This is all done overnight at cheap rate the house doesn’t cool down enough during the day for the heating to come back on again.

Posted by: @ngillam

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all the trickle vents are closed on the windows!!

Not the best option for ventilation! You will end up with a house that hot and stuffy, the stuffy feeling isn't because it's hot, its rubbish air quality, humidity and high CO2 levels