Okofen - starting temperature and some questions

[manual_]

Hello everyone!

We had an Okofen Pellematic Compact 18kW boiler installed in mid-October 2022. At first glance everything seems to be working since overall the installation heats up to the requested interior temperature (19°C or sometimes +1) and stops at 19.5°C and restarts when it drops below 18.5°C, therefore conforming to the programmed hysteresis.

okofen2.JPG (25.4 KiB) Viewed 4595 times

By taking a closer look at the operation and settings, I discovered the concept of a heating curve based on the outside temperature, which raised a lot of questions. Indeed, looking at the curves (obtained on HomeAssistant by making a request on the json file regularly, but it doesn't matter) it turns out that the actual water flow temperature does not respect the setpoint at all. The setpoint requested seems to respect the heating curve but the actual temperature is much higher.

okofen.JPG (24.25 KiB) Viewed 4595 times

So first question: why is the heating temperature set point not respected? It seems that we systematically reach a temperature around 53°C whatever the outside temperature.

Second question: today the boiler is heating up quite strongly, the temperature is rising, the boiler is shutting down, the temperature is dropping, etc. We end up with a yo-yo effect, even if in the end the variations in ambient temperatures are not very high. I still find that you feel when the boiler cuts out. I don't know how you define a short cycle but at first sight the cycles don't seem so short to me. I finally come to the question. What would be the ideal operation? The way I understand the heating curve, we should heat constantly but at an equilibrium temperature which should allow the temperature to remain at a comfort temperature (if it is well regulated) But suddenly all the time or you are programmed in "Comfort" the water should circulate. Today there is heating and circulation of water for 2-3 hours then several hours of breaks until the temperature is too low and re-heating and re-circulation.

Finally, last question: how does anticipation work? I set the lookahead duration to 180 min but I see absolutely no lookahead.

Last point, I don't know if it is important for the analysis of my problem but the outside temperature sensor is badly placed, it is too sheltered and does not register enough temperature variation. It will be a problem for the adjustment of the heating curve but I do not think it has a link with the non-respected setpoint temperature.

Thank you in advance for your assistance! Ideally I would have liked my installer to be able to guide me but a priori not the time/desire/skills? To have gone through this a little forum I think I can find help here. I am aware that there is probably missing data so do not hesitate to ask for additional information. I have archived all the csvs for a few weeks if needed.

Have a good day!

[sicetaitsimple]

You will certainly find help, there is at least one real specialist on the forum, Pilpoil.
That said, I still have a question: Looking at the "temp int target" curve, it seems that you only want to "heat" over short intervals, a few hours, in the morning and in the evening, by putting the temperature target around 7/8°C the rest of the time. Did I understand correctly or does the "temp-int-target" correspond to something else?

[manual_]

In fact we are in "comfort" mode from 6 to 8 in the morning, setpoint around 19°C then again from 16 to 22 p.m. in the evening. The rest of the time we are in "reduced" mode with set point around 17°C but no heating if outside temperature higher than +5°C

In the data returned by the json, if we are in comfort mode but the temperature is reached, or if reduced mode but outside temperature higher than +5°C, then the set point automatically changes to 8°C, hence the chart appearance

[sicetaitsimple]

Seen, okay.

[Pilpoill]

Hello everybody

You will certainly find help, there is at least one real specialist on the forum, Pilpoil.
...

Uh thank you Sicetaitsimple but I do not deserve such a qualifier

Let's say that at one time I spent as much time at work as afterwards studying the functioning of the Okofen...
Two different things but which I like so when I have the time and well I try to help to the extent of my skills.

Those who register on the forums to send me a private message directly, I'm zapping!
Those who ask a question that is answered and then disappear without saying anything because their problem is solved, if I could have them in front of me just for a coffee to explain to them the meaning of the word respect
I am not the installer let alone the Okofen technician in anyone's area…
Also over is the period when I was just being given files and asked what to do next, it's as time-consuming as possible and out of the question that it encroaches more on my already busy professional and personal life.

Now that things are clearly laid out by the irascible Pilpoill, I would like to take a look at a machine already connected.

It's up to Manu to decide if he hasn't already fled

[sicetaitsimple]

Hello everybody

You will certainly find help, there is at least one real specialist on the forum, Pilpoil.
...

Uh thank you Sicetaitsimple but I do not deserve such a qualifier

From what I observed, I think so! Now I understand that you also want to limit your "counseling" time to what you find personally acceptable and to people who behave correctly.
I promise, I won't advertise you anymore, and besides, I don't have an OKofen boiler, it's not interested!
Good continuation.

[Pilpoill]

From what I observed, I think so! Now I understand that you also want to limit your "counseling" time to what you find personally acceptable and to people who behave correctly.
I promise, I won't advertise you anymore, and besides, I don't have an OKofen boiler, it's not interested!
Good continuation.

My thanks were (and remain!) nonetheless sincere to you.

I just put things in a dry but understandable way for profiteers, absolutely not against you, sorry if you perceived it that way

[sicetaitsimple]

absolutely not against you sorry if you perceived it that way

I didn't see it that way at all, I just realized that quoting you was certainly inappropriate on my part, I don't have to interfere between you and possible advice seekers.
Well, my gas boiler works very well! As long as there is gas...

[manual_]

Good evening!

To be clear, my approach is above all intellectual. As stated at first sight the boiler works. I saw that we could recover data from the boiler, it aroused my curiosity, I spent a lot of time looking and trying to understand how it works, and I deduce that certain things seem abnormal. Typically in my case the fact that the starting water setpoint temperature is not respected. I find it quite frustrating not to understand and so I went in search of explanations.

As I can't really count on my installer for the moment (rather long response time, especially if the boiler is working and not necessarily full confidence in them), I turned to this forum where I seemed to see people with some experience with this type of boiler.

In short, I'm not looking for a turnkey answer without understanding, but rather sharing my thoughts with people with knowledge and skills. This will allow me then by having a better understanding to make sure that my installer solves the problem properly.

So to come back to the initial problem, let's start with the basics: is it abnormal that the set point for the water flow temperature is not respected? If this is the case as I think, can we imagine a three-way valve mounted upside down? Which would open when it should close and vice versa?

Thank you to everyone who will take the time to reflect with me.

[manual_]

Hello,

For info if other people had this problem. My installer came by and we were able to fix the problem. The three-way valve was incorrectly configured. His zero point was not good. Basically even in the fully closed position it let too much hot water.

Now I start on a good basis to refine the heating curve.

Have a good day!