Which of the following is NOT listed as an advantage of storage heaters?

• A. Clean
• B. Easy to install
• C. No plumbing
• D. Heavy

Answer: (D)

Storage heaters store heat in a high‑mass core during off‑peak electricity so they can release warmth later, which is why they’re praised for being clean and simple to install. Because they don’t burn fuel, there are no combustion byproducts, no fuel supply to connect, and no exhaust or venting to manage, so they’re clean and quiet. They don’t require any plumbing or hot water circuits either, since heat is stored and distributed when needed through convection or built‑in vents, not through a boiler loop. They’re essentially a plug‑in heat source, so connecting to the mains is the main requirement.

The idea that weight is an advantage doesn’t fit here. These heaters tend to be quite heavy due to the dense heat‑storage material, which is a practical drawback rather than a benefit. So the aspect that isn’t listed as an advantage is the heaviness; the other points—being clean, easy to install, and not needing plumbing—are the typical advantages.