Gassafe

http://www.gassaferegister.co.uk/

HSE (Landlords Gas Safety)

www.hse.gov.uk/gas/landlords/

Kamco Powerflushing CF90 and chemicals

http://www.kamco.co.uk/powerflushing.html

Adey Magnaclean

http://www.adey.com/installers/filters/magnaclean-professional

Glow-worm

http://www.glow-worm.co.uk/

Vaillant

http://www.vaillant.co.uk/products/domestic-boilers/

Worcester

https://www.worcester-bosch.co.uk/