機器
background
boiler
broken
calcification
calcium
chalky
corrosion
crack
crusty
damage
damaged
decay
dirt
domestic
electric
electrical
element
equipment
failure
hard
heat
heater
heating
incrustation
isolated
laundry
lime
limescale
metal
mineral
obsolete
old
problem
protect
rubber
rusty
salt
scale
scrap
scum
sediment
soot
stainless
steel
technology
washing
waste
water
white