solar hot water

Hi, I have a solar hot water system in my house (came with the house when i bought it) The pressure in the system is low and i want to top it up. (lower than shown in the attached picture) the system is filled with a glycol mix, so i would have to top up with that fluid. but i am wondering...

Hi, Got solar hot water tubes on the roof, don’t know much about them but they don’t seem to operate correctly, when there turned on the raydan controller temp display is very sporadic and jumps around and occasionally the relay which controls the circulation pump is constantly clicking on and...