This is an override for a Vampires item. It will continue to appear in all the same categories as before plus now appearing in the Electronics category. The tuning is based on the Snowy Escape space heater and uses those buffs so this requires both Vampires and Snowy Escape.
Unlike the space heater there is no visual indicator that the heater is on. It actually originally inherited the glowing lines but I removed them because floating red lines look stupid. You just have to figure it out from the buffs and from clicking. I haven’t had a radiator since I was a kid but I don’t remember those having a visual indicator anyway.