Reduced mode problem with gray TEM and Okofen

[dirk pitt]

interesting your spreadsheet.
I will look at it.
just a thing, the conditions of switching on and off of the burner do not seem correct. it is not easy to do because the condition at a time depends on the past condition.
example, you can be at 68 ° cooling, it is off
you can be at 68 ° heating, it is on.

in short, it is a detail.

[Bedouin]

I'm relaunching this post because I don't understand it anymore ....

After a day of heating, we go into reduced mode say at 19:00. At this time the house is warm, say 21 C.

The outside temperature on the regul. is +2 C.
The lowering limit is + 3 C.

So the lowering mode is active.

The regulator calculates a TD of 15 C.

I see:

- The ciculators continue to operate.
- The V3V is gradually closed by regulation pulses.

However as the underfloor heating is in temperature the water which circulates there is around the 25/27 degrees what corresponds to the TD read by the regul. The latter does not stop trying to close the V3V because it seeks to reach the 15 C calculated by the regulation.

No one has noticed this kind of problem?

for me, in reduced mode, the circulators can possibly still turn but not the V3V.

the situation I am describing can last all night because as long as the water in the floor is> 15 C the regulator sends impulses to the V3V to try to close it, but it has already been fully closed for a long time.

[Xian]

the situation I am describing can last all night because as long as the water in the floor is> 15 C the regulator sends impulses to the V3V to try to close it, but it has already been fully closed for a long time.

when you press the "thermometer" button of the TEM for a few seconds, different values ​​scroll, preceded by "soll" or "ist"; as long as "sol" is not equal to "ist", the TEM commands the closing or opening of the valve.

"Soll" is the temperature that the water in the circuit should have according to the water law, "ist" is the temperature read by the corresponding probe.

In the case of which you speak, even if the valve is closed, insofar as the measured temperature is higher than the theoretical T °, ​​the TEM continues to give a closing order, because the TEM does not know the degree of opening or closing the valve.

[Bedouin]

@Xian

I understood how we access the values ​​calculated by the regulator and it is to these values ​​that I am referring.

I understand your remark about the fact that the regulator does not know the positions of the V3V.

However if the calculated TD (by the regulator) does not bring to the building according to the formula:

TD Inactive = Programmed room temp + (2 x (1 + Slope))

At home in reduced mode the limit is 21.
Now the calculated TD is 15 therefore less than 21 so everything should be stopped? Except that since the standby no heating limit (3-4) is at +3 and outside it is +2, we should be in lowering mode, which a priori takes precedence over the previous rule.

Except that the doc says otherwise, if at least one of the stop conditions is reached, the heating is off.

[Did67]

Does this situation last, or did you just notice it by switching to "night" mode ???

At home (with a gray TEM), I noticed the same thing at the time of the changeover, and later in the evening, everything was stopped!

I have not (yet) explored the question: a duration of "post-circulation" which plays ???

[Bedouin]

Hello,

Does this situation last, or did you just notice it by switching to "night" mode ???

It seems to last. I do not stay all night in front :-) but I go into reduced mode from 19:00 and the problem remains the same again around midnight ...

I have me (with a gray TEM), I noticed the same thing at the time of the changeover, and later in the evening, everything was stopped!

On mine, 2 observations:

- Either the circulators are ON and the V3V is controlled (probably post circulation ...)

- Either the circulators are OFF but the regul. continues to send pulses to the V3V to close it by repeated small strokes to (I think) try to reach the calculated TD of 15 C while the water circulating in the floors is still at 24/25 degrees.

Now I guess if this temperature goes down fast enough to this temp. calculated and that the temp. Ambient sensors too, this displaces the problem or even eliminates it, but this is not the case with me, it is only an assumption.

I have not (yet) explored the question: a duration of "post-circulation" which plays ???

Post ciculation, normally it's 30 minutes I think ...

[Bedouin]

A priori it would be normal and mainly due to the inertia of my floor, although I have a wooden house. (according to Okofen).

In fact the V3V closes so that the hot water from the floor can circulate in a loop. As the V3V is closed, this assumes that there is indeed a load shedding valve (this is my case) which only trips after a certain pressure. This allows the boiler floor to be isolated during this phase of transition to reduced mode. The regulation meanwhile, it invariably tries to close the V3V to reach the calculated starting temperature (15C) in my case, but as there is a lot of inertia, it takes a long time to arrive.

As all this is dynamic, after a few hours, the temp. ambient starts to descend and the new calculated TD is no longer 15 but gradually 20 then 25 and possibly the boiler restarts to maintain the 18C setpoint according to the heating curve. All this implies compensation other than 0, I put 4 for underfloor heating.

Then the reduced mode setting (factory = -5) must be a function of the house, its insulation and its inertia so that the temp. chosen does not give rise to a temperature drop below the reduced setpoint.

[Bedouin]

Bof, all that is not coherent ...

Yesterday evening at 20:00 p.m. everything was stopped, neither V3V nor circulator. However, the conditions are the same as 2 days ago.

Around 23:00, everything is stopped, except the controls of the V3V alone which are desperately trying to close the V3V already completely closed.

But that's normal.

[Xian]

Bof, all that is not coherent ...


But that's normal.

you need a "big sigh" smiley ... ;-)

[Bedouin]

Now -2 C outside, snow.

21 in.
Stop for 180 min.

But since 20:00 the valve closing pictogram is permanently displayed.