An apparatus for use in humidified gases delivery treatment comprising: a housing , a pressurised gases supply within said housing , a pressurised gases outlet in said housing in fluid connection with said pressurised gases supply and adapted to make fluid connection with an inlet of a heatable water chamber in order to provide gases flow to said chamber , a humidified gases return in said housing , adapted to make fluid connection with an outlet of said chamber in order to receive humidified gases from said chamber , a chamber heating means connected to said housing and, said housing includes a humidifier engagement locating said chamber adjacent said chamber heating means , said chamber heating means adapted to vaporise liquid water in said water chamber in order to provide water vapour to said gases flow passing through said water chamber , a patient outlet in said housing , in fluid connection with said humidified gases return in order to receive humidified gases from said humidified gases return and provide humidified gases to said patient outlet , said patient outlet being in fluid connection with or adapted to make fluid connection with a breathing conduit for delivery of humidified gases to a patient, and wherein said water chamber has a base, and said chamber is engagable with said humidifier engagement via a single motion of engagement, and said single motion of engagement urges the base of said chamber adjacent and in contact with said chamber heating means and makes a first fluid connection between said pressurised gases outlet and said chamber inlet , and makes a second fluid connection between said humidified gases return and said chamber outlet , with said first and second fluid connections being made in the direction of said single motion of engagement. a housing , a pressurised gases supply within said housing , a pressurised gases outlet in said housing in fluid connection with said pressurised gases supply and adapted to make fluid connection with an inlet of a heatable water chamber in order to provide gases flow to said chamber , a humidified gases return in said housing , adapted to make fluid connection with an outlet of said chamber in order to receive humidified gases from said chamber , a chamber heating means connected to said housing and, said housing includes a humidifier engagement locating said chamber adjacent said chamber heating means , said chamber heating means adapted to vaporise liquid water in said water chamber in order to provide water vapour to said gases flow passing through said water chamber , a patient outlet in said housing , in fluid connection with said humidified gases return in order to receive humidified gases from said humidified gases return and provide humidified gases to said patient outlet , said patient outlet being in fluid connection with or adapted to make fluid connection with a breathing conduit for delivery of humidified gases to a patient, and wherein said water chamber has a base, and said chamber is engagable with said humidifier engagement via a single motion of engagement, and said single motion of engagement urges the base of said chamber adjacent and in contact with said chamber heating means and makes a first fluid connection between said pressurised gases outlet and said chamber inlet , and makes a second fluid connection between said humidified gases return and said chamber outlet , with said first and second fluid connections being made in the direction of said single motion of engagement. <EOS>