[Solved] How to properly set the water flow on the example of Wilo STRATOS PICO 25 / 1-6

When commissioning for the first time, set the water flow in m3 / h. Can I ask for help on how to properly calculate this parameter?

Set up experimentally. So that you get back from the radiators evenly warm.Good luck. This will take a while.Start from the smallest gear.

spider_net wrote:

Can I ask for help on how to properly calculate this parameter?

The flow of water depends on the power demand.
For radiators, the temperature difference is so-called. delta t = 5, 10, 15 or 20 degrees.
For delta t = 20, accept 23.26W for 1l / h flow.
The smaller the delta, the power for 1l / h decreases proportionally.
This means that if the temperature difference is 2x less (delta t = 10), the power will be halved and will amount to 11.63 watt.
Analyzing this case further, wishing to maintain the same power, for a temperature difference of 10 degrees, the water flow must be 2x larger than for a temperature difference of 20 degrees.
Of course, the radiator's power depends on the size of this radiator.

You need to know for what water temperature you have selected radiators and then you add the heaters' power for these parameters, depending on the delta you divide by the specified power for 1l / h and the flow of 1 / h will come out.
1m3 / h = 1000 liters / h
Considering the average power of radiators, a maximum of several hundred liters per hour is at stake.
Only the flow of water must be correlated with the power of the boiler, in order not to boil water on the boiler, therefore a trial and error method awaits you to reconcile all these dependencies.

spider_net wrote:

When commissioning for the first time, set the water flow in m3 / h. Can I ask for help on how to properly calculate this parameter?

Are you sure that it is about m3 / ha, not the lifting pressure in meters?

I apologize for the wrong parameters. I read too much before buying. They wanted to raise the water column. Interestingly, the calculator wilo indicates that the parameter in my case set at the level of 1.7 m, but I really see that the heat reaches the last heaters at the level of approx. 3.3 m (so far I'm investigating the installation behavior). The pump works in dynamic adapt mode - I wonder if this makes sense in the case of heating with a coal boiler with blower controller "comfort", where the temperature is "floating." At present, the boiler operates during the day about 8h (I smoke with the open chamber, disconnecting the blower) After using up fuel (approximately 20kg of coal on average) there is a slow extinguishing - here the night-time function is noticed, which notices a drop in temperature and automatically reduces the flow.I went a step further when it comes to savings in heating and replaced the old pump, while on the head I mean another idea - purchasing a solid gas furnace Before that, however, I will look for some co-financing program from the Environmental Protection Fund, etc.

The lifting height of the pump is different from the difference in height between the pump and the highest point of installation. The lifting height, eg 4m, means that the pump will pump water out of a well of a depth of 4m. In the installation, the pump does not pump out the water but only causes circulation and this is a difference. In a radiator installation, usually the pump does not need high power which depends on the resistance of the installation (pipe cross-sections)
If you have a pump with autoadapt then in this mode it should work - it selects the power depending on the need

I have been using the device for a while and I can boast of his work. On point The night mode deserves a negative - I think it does not work well with a coal-fired boiler. But considering the fact that the coal boilers are on "displacement" I think that the producer will not approach the topic. As to the failure rate, it is difficult to say. Earlier, I used the pump - a very noisy pump which fell after about 6 years of use. I hope that wilo will go a bit longer