A washing apparatus for washing medical devices, said washing apparatus having: a washing, chamber; a sump 26 at the bottom of the washing chamber for collecting and holding fluids; a heating element in said sump for heating fluids in said sump; a sprayer (44A, 44B) for spraying said fluids on said medical devices to be cleaned; a pump for pumping fluids in said sump to said sprayer (44A, 44B); and three fluid inlet lines (72, 62, 82) for providing fluid to said washing chamber, said fluid inlet lines (72, 62, 82) being connected to respective fluid diffusers (74, 64, 84) that are mounted to a top wall of said washing chamber, each of said fluid diffusers (74, 64, 84) being comprised of a tubular body portion having a domed portion at one end thereof, said domed portion having an inner chamber, said inner chamber communicating with the exterior of said domed portion through a plurality of side apertures extending through said domed portion, each of said side apertures being oriented toward said top wall, wherein cold water, which is introduced into said washing chamber through a first of said fluid inlet lines (72, 62, 82) and a first of said fluid diffusers (74, 64, 84) connected to said first fluid inlet line, is distributed into said washing chamber through said first fluid diffuser such that said cold water is directed toward said top wall by said first fluid diffuser, wherein hot water which can be introduced into said washing chamber through a second of said fluid inlet lines (72, 62, 82) and a second of said fluid diffusers (74, 64, 84) connected to said second fluid inlet line, can be distributed into said washing chamber through said second fluid diffuser such that said hot water can be directed toward said top wall by said second fluid diffuser, wherein pure rinse water at or below room temperature, which can be introduced into said washing chamber through a third of said fluid inlet lines (72, 62, 82) and a third of said fluid diffusers (74, 64, 84) connected to said third fluid inlet line, can be distributed into said washing chamber through said third fluid diffuser such that said rinse water can be directed toward said top wall by said third fluid diffuser. a washing, chamber; a sump 26 at the bottom of the washing chamber for collecting and holding fluids; a heating element in said sump for heating fluids in said sump; a sprayer (44A, 44B) for spraying said fluids on said medical devices to be cleaned; a pump for pumping fluids in said sump to said sprayer (44A, 44B); and three fluid inlet lines (72, 62, 82) for providing fluid to said washing chamber, said fluid inlet lines (72, 62, 82) being connected to respective fluid diffusers (74, 64, 84) that are mounted to a top wall of said washing chamber, each of said fluid diffusers (74, 64, 84) being comprised of a tubular body portion having a domed portion at one end thereof, said domed portion having an inner chamber, said inner chamber communicating with the exterior of said domed portion through a plurality of side apertures extending through said domed portion, each of said side apertures being oriented toward said top wall, wherein cold water, which is introduced into said washing chamber through a first of said fluid inlet lines (72, 62, 82) and a first of said fluid diffusers (74, 64, 84) connected to said first fluid inlet line, is distributed into said washing chamber through said first fluid diffuser such that said cold water is directed toward said top wall by said first fluid diffuser, wherein hot water which can be introduced into said washing chamber through a second of said fluid inlet lines (72, 62, 82) and a second of said fluid diffusers (74, 64, 84) connected to said second fluid inlet line, can be distributed into said washing chamber through said second fluid diffuser such that said hot water can be directed toward said top wall by said second fluid diffuser, wherein pure rinse water at or below room temperature, which can be introduced into said washing chamber through a third of said fluid inlet lines (72, 62, 82) and a third of said fluid diffusers (74, 64, 84) connected to said third fluid inlet line, can be distributed into said washing chamber through said third fluid diffuser such that said rinse water can be directed toward said top wall by said third fluid diffuser.