New boiler installed WB Greenstart 30CDi standard - hw cylinder with stat. The boiler has digital display showing the temp of water going through it's pipes which if set low can be 50 degree C for example - my question is if the hw stat is set to 60 degree C will the boiler ever heat the water to 60 ?
It is normal practice to set the boiler temp to 82-85 degC. That will heat the water in the cylinder up to 60 as quick as possible. The tank stat will then turn the boiler off. This is supposed to be the most efficient way of doing it.
As you say, if the boiler temp is only set to 60, then the hot water will take a long time to get up to temp and may never actually reach 60.
Most boilers control on the return water temp. in order to know the system is up to temp.
If this is what is being displayed, then the flow temp. will be considerably higher thus allowing your hot water cylinder to achieve its set temp.
The handbook should confirm if this is so.