vaillant vsmart heat curve

[Harry Bloomfield]

range rating so the boiler only uses up to a certain amount of power.

That's what I assumed you meant, but wasn't sure. Unless you have a good reason to limit it, leave it to the Vsmart to decide what power it needs - leave it on auto. That setting is there for more basic control systems where all they can do is on or off demands for heat, whereas the Vsmart can tell the power just how much heat is required, from its calculations.

 

[GRhodie]

thank you. Does your vsmart take 10 minutes to fire up the boiler when you put in a temp rise?

 

[Harry Bloomfield]

thank you. Does your vsmart take 10 minutes to fire up the boiler when you put in a temp rise?

If I tweak the temperature up manually, no, but delay depends on the system design. I have an open vented system, cylinder and a 3-port MOMO type valve. Turning the temperature up, first moves the 3-port to the correct position, if it is not there already, then there is a delay whilst the system works out the demand level it needs to meet, a purge cycle, a pause, then it fires.

Usually around two minutes. Though much longer if it is dealing with a demand for water heating, because it priorities that, ignoring heating demand until the water is satisfied.

 

[GRhodie]

thank you. i just have vsmart to ebus. thank you for help and information.

 

[GRhodie]

althought my boiler has started lower it seems once temperature is nearly reached it has increased its heat. see picture

 

[Harry Bloomfield]

althought my boiler has started lower it seems once temperature is nearly reached it has increased its heat. see picture

I have no means to record my boilers performance, apart from the indoor display of my Smart gas Meter, which out of curiosity, I have been watching for a few days. It's an 18Kw boiler what seems to happen when I nudge the temperature up on a morning a couple of degrees, is purge, a few minutes of burn at around 18Kw, then as it nears the new temperature it gradually ramps its output down to a little under 5Kw. It then cycles as needed on the minimum.

 

[GRhodie]

thank you. again i have noticed that it was keeping an even temp then all of a sudden 100per cent. not sure whats happening as it wasnt warming up. so i nudged the thermostat up and more heat coming through.

 

[John D v2.0]

defintely turn off the adaptive heat curve if the controller is in a room that gets bonus heat from cooking, sun, lots of people, etc. Ours managed to adapt its heat curve down to about 0.3 when we had all the warmish weather over christmas as it was getting enough heat from the kitchen side, then the first cold day we had it was freezing in the house as it needed to be on 1.3. This could be what happened for you.
The heat curve is setting the boiler water temperature, not the boiler power, as the water temperature is what's important for efficiency and comfort. Ours is set up for both weather and load compensation, so a colder outdoor or room temperature, or a higher target temperature will all make the boiler temperature increase.
Hope some of that's useful! Take care.

 

[GRhodie]

its working ok but did notice it was coooler the other evening as temp plummeted.

 

[Harry Bloomfield]

its working ok but did notice it was coooler the other evening as temp plummeted.

Cooler as in feeling cooler, or cooler as in not meeting the desired temperature?

 

[GRhodie]

not quite hitting the temperature. but once i raised temperature by 0.5 deg working perfectly

 

[Harry Bloomfield]

If it really is lagging the desirable setting, nudge the curve number up a notch.