Assertion: water heater's water | /r/HasProperty | preheated
Facets:
Source sentences:
text: When there is insufficient sunlight, the water is preheated and a back-up system takes over to bring the water to the required temperature.
text: Water is preheated as it passes through a stainless steel heat exchanger, capturing any extra heat (or latent heat) before it escapes into the vent system.