Digital solar controller

hot_rod

aka ∆T control.
So many nice features in todays digital controls. They keep track of a lot of data. They have triac relays and can vary the pump speed based on collector temperature.
The energy meter function is nice to see how much energy you system actually collects.
the control knows run time, delta T and you enter the gpm from the flow meter. Now you have a BTU meter.
If you run the pump in variable speed mode it also knows the energy calculation.
Over heat functions, vacation mode, and a lot more.
Easy to connect to a data logger site also.

Light years ahead of the Goldlines and probably less stand by power consumption.
I have a bunch of the 12 and 24VDC models if anyone is interested.

https://www.resol.de/Produktdokumente/48005931_DeltaSol_BS_Plus_V2.monen.pdf

dko

For data geeks and control freaks these are amazing. So much fine control and available data.
Looking through their other products.. so many different controllers, accessories, and sensors.
The Grundfos direct sensors that can be controlled with pwm output controls are great as well.

I think they have one of the best manuals for their products i've ever seen.

hot_rod

They have a Google group for support also. Daniel is one if the engineers that works at Resol
You can learn interesting applications by reading through the questions now and then

https://groups.google.com/g/resol-vbus