T ° departure always lower than t ° setpoint

[patrice42440]

Bonjour à tous
everything is in the title! I noticed that my departure temperatures are always lower than the set temperature (I have 2 heating circuits).
It could be good, except that I freeze in the house ...
Do you have an idea?
Thank you in advance

[dirk pitt]

we need to tell us a little more. which boiler, which regulation, which settings, etc.

sorry, don't link to your other post.

[boutkiller]

It may just be a calibration problem, or the position of the temperature probe on your circuit.
I have this problem on my boiler, I have 10 ° difference between the setpoint and the actual temperature, it is enough simply to adjust your setpoint temperature to have the desired actual temperature.
Have you tried to increase your set temperature?

[patrice42440]

ah yes sorry!
Okofen Pellematic 32, with the new regulation. Room sensor on one circuit only.
I am not talking about the ambient temperature, but rather the temperature of the water leaving in the circuits, which almost never corresponds to the temperature calculated by the boiler (flow instruction).

[elephant]

I may be wrong, but whatever the boiler, we must calculate the T ° of boiler water (possibly empirically if it does not do it alone) according to the outside T °

1) so that it is sufficient to heat to the desired temperature

2) not too hot, otherwise we spend the desired T °

T ° desired: temperature of the room where the room thermostat is located.

[dirk pitt]

ah yes sorry!
Okofen Pellematic 32, with the new regulation. Room sensor on one circuit only.
I am not talking about the ambient temperature, but rather the temperature of the water leaving in the circuits, which almost never corresponds to the temperature calculated by the boiler (flow instruction).

OK if the radiator valve temperature is not respected it is either that the parameters of the regul are not good, or that the hydraulic circuit does not allow a correct regulation.
on the regulation side, I see in particular the settings concerning the parameters of the 3-way valve which may not be suitable. it should be observed what the V3V does, does it make large amplitudes without managing to stabilize or on the contrary, one has the impression that it only moves very little.

hydraulic circuit side, it can be a circulator problem. if your circulator is recent and has an "auto" position, force it to a fixed speed but do not leave it in auto. otherwise, if it's a 3 speed circulator, try to lower the speed.

[Did67]

Where is your probe placed which measures the leaving water temperature? Right after the mixer V3V?

If yes, first thing to check: is there a good contact ???

What surprises me a little is that normally, regulation acts by successive approaches:

- if the start temp is lower than the set point, it opens a little

- if it is still not, it gives a blow ...

- if it exceeds, it closes a blow ...

In fact, therefore, the actual, measured leaving temperature will "spin" around the calculated setpoint ...

How much are your gaps ??? If it is one or two degrees, we are in these trial and error, normal ...

The fact that it is not warm enough can also be explained by an unadjusted heating curve.

Has this been done?

[patrice42440]

Thanks for the tracks.
Yes the probes are placed just after the V3V.
The differences in temperature are not just a few degrees (otherwise I would not have noticed or noted it).

[manet42]

If the boiler does its job, it makes hot water, the regulator makes a good calculation, correct starting temperature and that the heating circuit does not follow, like my predecessors, I see only two tracks:
- Circulator badly adjusted, it cannot send enough hot water.
- The 3-way valve which does not open enough, same consequence.

[Did67]

To make the diagnosis, we will have to observe a little finely, a certain number of cycles:

- when the boiler starts: boiler temp; calculated start temp; actual start time [the V3V may have been closed, protecting the boiler against condensation; it is then quite normal that for "a certain time", the start time is not close to the start time setpoint; regulation acts "piecemeal"; so it takes "a while" for everything to balance out

- then, the boiler should start modulating = adapt its power to the heating requirement ... During this phase, "to within a few degrees", we should have the measured start time which is close to the start time setpoint .. .

During one-off observations, you can "come across" situation a) and draw wrong conclusions ...