Balancing HW and CH Gate Valves

[ninjaef]

as per title.

Gate Valves are on the return from HW Tank, and on the CH line. See pic. Both are currently WIDE OPEN so previous owner or tradesman has messed about and not balanced correctly because normally these are set for the system then the heads removed to avoid this problem.

I have a decent infra red temp measure gun, so can I balance the system by measuring the temperature drops and if so, at what points in the pipework do i aim the laser at? and what should be the degrees Celsius drop values?

Thanks

 

[ninjaef]

sorry, here is the image, gate valves highlighted in purple