flush

Hi guys, I know it's important to flush out new radiators before fitting to the loop but do you need to flush out the other parts like the CPU block or GPU block, reservoir etc as well? Thanks :)

;tldr version: First time at water cooling, bought a kit. Ran fine until I added blue dye from kit, and now it's all bubbles and noisy, and they're not shifting. Want to flush it and start again - can I use tap water for the flush? Long version: Purchased a 'Liquid Cool 240 mm Vortex One...