Default cp ≈ 4.186 kJ/(kg·K) for liquid water (approximate).
Approximate sensible heat Q = m · cp · ΔT with positive mass, finite temperature change, and specific heat defaulting to 4.186 kJ/(kg·K) for liquid water if missing/invalid. Result is shown in kJ; phase change and losses are not modeled.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.