What is your spec? Does it have a blending valve on the flow and return?

No blending valve. The indirect coil comes unadorned. There is a
thermostatic mixing valve on the DHW outlet, though.

I'm certainly interested in anything that can reduce the return temperature,
though. I wouldn't mind reducing the radiator flow temperature, too, for
safety reasons. I have a five year old, whose bed is adjacent to a radiator.
Can blending valves achieve this?

Christian.