This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
燸 combines 火 (fire) with 需, which likely contributes the sound. The exact historical development is uncertain.
With fire 火 on the left and 需 on the right, imagine a fire used for warming something needed, but the exact meaning is unclear.
For ニュ, picture a new fire being lit: new -> ニュ, and the fire 火 warms what is needed 需.