Heater in Baby Sign Language
Figure: Avocado in Baby Sign Language

Signing: To sign heater begin with your dominant hand by your mouth with all fingers together. Quickly open your fingers in a shake-downwards movement followed by both hands moving up and down in front of you with fingers extended and curved with palm facing toward your body.
Usage: You can use heater When you are explaining to baby the water heater used when you draw their bath

Related Signs: Hot, Cold.