Octopus Energy UK installed my Daikin EDLA04E2V3 in march 2024. They set it up to run from WD curve without Thermostat (madoka) influence and with dT of 5c. All radiators used from gas heating, were replaced to heat pump design spec.
They setup a 2 point curve
y2 is 50c
y1 is 25c
X1 is -7c
X2 is 18c
The system runs 24/7 and house temp of 20c is required in the day and during night 18c (using -ve offset on LWT … from 2200 to 0600). They set this in march with an ambient of 10c.
The problem is that I am having to adjust offset DAILY every time ambient temperature changes , is utterly contrary to the whole purpose of the curve. This is to say that with a correct curve, a fairly constant room temperature should be able to be maintained irrespective of the ambient temperature. for that is the whole purpose of a WD curve isn’t it. There must be a more suitable"method" here?
Case example…
Let’s say it’s minus 5 , I set the offset. The next day it’s 0, I need to set the offset again . The next day is 5 degrees I’ve got to set the offset again The next day is minus 1. I’m going to set the offset again … clearly this isn’t the right approach and there must be a better way of doing this and that’s what I’m asking.
So may I please ssk the question in a very very very basic terms given the above… for the 2-point WD curve values set above… ambient of 10c…and by adjusting I refer to y2, y1, X1, X2.
when it is colder (than 10c) outside and I’m too warm What do I adjust?
when it is colder outside and I’m cold what do I adjust?
when it is warmer outside and I’m too warm What do I adjust?
when it is warmer and I’m cold what do I adjust?
when adjusting, If I have to adjust multiple values then by how much do I adjust each value equally, or one more than the other, or one less than the other?
y2 is 50c
y1 is 25c
X1 is -7c
X2 is 18c
thankyou and please … i have read the manual and other guides , they didn’t help so more helpful support needed
The installer reference guide (EBLA04-08EV3.EBLA04-08E3V3.EDLA04-08EV3.EDLA04-08E3V3_Installer reference guide_4PEN685228-1B_English) provides this chart on page 147:
You really need to set the lower limit when the ambient temperature is cold (around freezing or ideally design temperature of -3) and the upper limit when ambient temperature is mild.
I can tell you for sure that having y1 @ 25C will not be a good value for your Altherma 3. These units can only really go to as low as 30C without cycling (which reduces efficiency and potentially makes the house feel less comfortable as the emitters are intermittently outputting heat).
this suggests you need to alter your curve ,
its took me all winter to get mine tuned in to a point where if nobody is home the house slightly cools and if more than two people are home with a tv on the temp slightly increases
i would start off by reducing your y2 to around 45 or lower if you can get away with it y1 to 28 and lower the x2 to he point where you want heat to start , leave it for a few days and adjust by one item by a couple of degrees
Madoka mode - the thermostat modulates the flow temp for you within 0-1.5c above thermostat setpoint and 0.5c below it.
LWT mode - this mode only makes sense if you have external control over the offset, such as with Home Assistant using the Onecta Cloud API integration. Or possibly if you have UFH but I don’t know anything about that.
Ultimately, there’s no getting around solar gain and human activities influencing the indoor temperature, so you can only do your best with the WD curve getting it right for gloomy days.
You’d want to set the low end after a couple of days without solar gain and temperatures are your design temp (-3c in my case) and the upper end at the point at which you don’t need heating at all.
Octopus preset my WD to 50c at -3c and 25c at 22c.
Nobody needs heating at 22c so that got lowered progressively until I reached 13c where the WD curve becomes a flat line again and you get a background level of heat.
The bottom end proved to need just 42c at -8c (resulting in a 38c flow temp roughly at -3), quite some ways below the design temp. This will be unique to your home’s own heat loss.
Temps are due to drop close to freezing tonight, so this could be a good time to experiment - assuming you’ve not had a big dollop of solar gain on your building fabric.
Try something like 45c at -7c and 25c at 14c. That’ll result in roughly a 10c drop in flow temp across the board. If your house is cooling, bring each end up a couple of degrees but at the same -7c and 14c points. It does take a little while but once you’re in the ballpark, Madoka with modulation of between 8 and 10 will then make the necessary adjustments to keep you closer to your setpoint.
guys I don’t want to seem ungrateful and I’m very grateful for your responses but can we please answer the four specific questions that I asked if you could just focus on the four questions and provide a clear answer for each referring to X1 X2 Y2 Y2 I REALLY WOULD APPRECIATE THIS PLEASE
how the heck is that going to heat any home? anything below 38c currently here (5c outside) means a cold house
33c…typical LWT for efficiency is 35C. 33c isn’t going to do anything, and that’s only at-14c, it’s 5c here…the pump shuts off at 25c !! where are you, Carribbean?
AHH my bad, looked like 33
apols.
built blurry view on my phone
still, 38c at -14… wouldn’t even tickle my home here in Lancaster., UK, … where are you?
what is that app you are using and can I get it and use it?
a heat curve takes some time to tune in at various different outside temps , its currently setup to design temps which is just starting point ,
you want the flow temps as low as you can get them without feeling cold ,
there is no exact answers to your question, the chart @mortstar posted is as good as it gets
surely it’s a simple question… with a given curve if I’m too cold or too hot what do 8 adjust?Very basic doesn’t need specific numbers and general advice for any system, surely there’s a common approach for any curve any system.
sounds like I’m in the wrong place, I have no idea what the app is or where you get it from or what how you use it
thank you very much guys for sticking with me but I think there’s an issue of communication let me give it one more try one last try very specifically could anyone reply with answers, using 1,2, 3, 4 in response to my 1, 2, 3, 4 very simple thank you one more go…
when it is colder (than 10c) outside and I’m too warm What do I adjust?
when it is colder outside and I’m cold what do I adjust?
when it is warmer outside and I’m too warm What do I adjust?
when it is warmer and I’m cold what do I adjust?
when adjusting, If I have to adjust multiple values then by how much do I adjust each value equally, or one more than the other, or one less than the other?
y2 is 50c
y1 is 25c
X1 is -7c
X2 is 18c
morstar just included the stock table from the manual which I’ve already got and It doesn’t answer the four specific questions referring exactly to how to adjust and when, read that table and my four questions again closely… specifically what is meant by regular temperature and cold temperature they’re not defined!!!
when your to hot you need to lower the flow temp @x outside temp and when your to cold you need to increase the flow temp @x outside temp
the left hand side of the graph (top number ) starting at the top number is your maximum flow temp the number below it is the minimum flow temp
the numbers on the bottom are outside temps
you can only really adjust the numbers as you feel to cold or to hot and it depends on what the current outside temp is and what your current flow temps are set up, if you cold you rather have to higher the maximum flow temp or adjust the outside temp to give you higher flow temps at the current outside temp
I don’t think you’re reading my questions actually and understanding how to respond but anyway I’ll leave it at that and I’ll close this account wasted time