Hi Terry,
I must apologise.
I got a bit frustrated with you last night and lost my rag.
I shouldn’t have done.
Please accept my apology, it was all my fault and you have done nothing wrong.
And please continue to ask any questions you need to and we’ll all try to help.
Matt
That’s kind of you. Thanks.
Good morning all. Well after my panic on the defrosting, I have been tweaking my WDC curve, so have now set it at 34 @-2 , 28 @ 16. I realised that at the low levels my radiators had virtually no capacity, barely worth being on.
However as I was doing this I spotted the operation modes, menu item 8.6. I noted that everything in there was set to OFF. I was wondering if that’s the same for everyone, or some have some settings, anti-frost for one, set to ON.
On another topic,Heatloss, having just re read some of the posts, I have been doing quite a lot of work on heatloss and as I suspect we all know infiltration can account for quite a lot of the heatloss. So if we are not encountering much wind then our heatloss should be substantially lower than the design specified heatloss. What I am wondering though , because the heatloss figures are not broken down, is what standard they are using. Presumably it’s built into the MCS calc somewhere and is specified per type of property?
I just found this article. New MCS requirement: heat loss calculations must follow new standard from June 2025
I’m fairly sure given how little time the surveyor was at my place that no sophisticated heat loss calc was done, so there must be some other method used! Particularly for calculating the infiltration losses.
This is under the “Information” menu and tells you what the unit is currently doing rather than being where you change the setting to allow it to do it or not. So when it says OFF for anti-frost, all that means is that it is not currently running the compressor because the Madoka room temperature is below the frost temperature. Likewise the Defrost setting means is it currently running a defrost.
If you want to check whether anti-frost is enabled or not, you goto Room > Antifrost (or field setting [2-06].
@jonathan , Thanks, I can rest easy on that one then.
The heat loss calcualation probably did go into detail but they decided not to let you have the full picture. When I was scoping things, I used the MCS Heat Pump Calculator spreadsheet - https://mcscertified.com/wp-content/uploads/2021/04/MCS-Heat-Pump-Calculator-Version-1.10-locked.xlsm. This uses three categories of building for air change rates, plus an account of open flues and mechanical extraction. I think that is what they would have used.
Wind certainly makes a lot of difference for us, as we are in an exposed location; I reckon on a lift of 2-3C on the LWT.
Adam, thanks, great resource.
So, spring is nearly upon us in the UK.
Coldish nights with usual HP action and warm spring like sunshine by mid morning.
Newbie question.
Do you experienced hands just let the weather curve do it’s thing and the LWT get to the cutoff point so the HP switches itself off, and then when the sun goes in the water temp drops enough through heat loss for it to come back on again?
Or, is there a better way?
i let the heat curve do its thing and have it set to turn off at 14 degree C outside temp
Similar for me, but my cutoff is 15C.
My first spring with a heatpump but we’ve had a few days already where the outside temp sensor has hit 15C and the heat pump has been off for a few hours. With the longer days the house carries the heat well into the evening.
Good stuff.
Our outside temperature sensor is in a very secluded spot. North facing and enclosed by brick wall to the east.
It’s a very cold spot -
It gets no warmth from the sun from any direction.
As a result it seems to keep the HP going for ages even though the house is overheating due to solar gain.
I guess I’ll have revisit my upper temperature points?
I did relocate my external temp sensor to a spot where it works the best for me. It’s north facing, but does get some indirect influence from the morning sun, which works out well as my east facing home office gets the morning sun, which is where I am in the mornings.
When the sun moves to the other side of the house, my home office cools and so does the sensor so the heat pump keeps my home office temp close to perfect.
Thanks for the insight.
Food for thought.
Makes me think more about sensor relocation - if I can’t get it under control by temp set points..
i would of gone down to 12 degrees c cut off but the system doesn’t allow it
Sneaky - I like it 
This is one obvious problem with what is essentially a “open loop control system”. There’s no feedback to tell the heat pump you are warm enough when there’s additional heat input beyond the control of the heat pump - except by you manually changing the settings. The weather curve predicts the heat you will require to maintain the desired temperature, based on the outside temperature. It knows nothing about any other heat source (or sink) that affects the house temperature. In your case, you improved the prediction by increasing the outdoor sensor reading roughly in line with the solar heat added to the house.
Agreed.
It’s something that will a little more thought from the manufacturers, I feel could be done so much better.
A second temp sensor in the sun that can be given some say and an internal set up that was not just like a gas boiler on / off.
The Madoka seems to be a disappointment in it’s attempt to give inside temp and assist in an effective regulation.
I did have it working quite well with the weather curve determining inside temps and Madoka set higher to keep it out of the way - so sort of bypassing it.
But it sabotaged our using the Eco DHW setting - in spite of the setting in the MMI giving priority to DHW it was overridden regularly. Not so with LWT setting.
What we want is to be able to modulate down enough but not hard switch off. This is also good for our DHW run at 1pm as the HP is prepped and ready at least that’s how I envisage it - my kW usage data points to this too.
Once summer is here proper of course the heating will be off OFF:)
DHW only..
Just wanted to post, anti-frost will do basically nothing on a Madoka controlled system unless indoor temps drop very low. Which is why it’s under room menu.
If you have an third party thermostat you should probably turn off anti-frost as it will cause the HP to come on full chat if you set it back overnight and it’s cold, and your thermostat should trigger it if needed (unlikely).
The key protection people confuse it with is water pipe freeze prevention which is the one that protects the external pipework by sampling the water temps.
The outside sensor definitely can play havoc with the Daikin at this time of the year. Mine is in a location that never gets the sun on it. Find the back of the property ( where the lounge and kitchen are situated ) get very warm but the HP keeps running ( the Madoka gets up to 22° ). Like yourself may need to find a better location.I find now I am at the state were I reduce the Madoka temperature way down so HP goes off and increase after tea when temperature starts to drop.