Take the tour ×  enter image description here  I have an old
space heater running along the outside-facing walls. It's a very
simple heater: it consists of a pipe, a heat sink all along it,
and a cover. I don't know what's inside the pipe; most likely
water or oil.  When the heater turns on and turns off, it makes
very loud clicking sounds in the bedroom -- loud enough to
consistently wake up my wife and me. These clicks happen every
couple of seconds for several minutes. And considering it heats
up and cools down basically every hour, this results in
interrupted sleep and anger at the heater.  My best guess is
that the metal is ticking when expanding and contracting, but
what can be done to reduce the noise? Surely it wasn't ticking
like this when it was brand new.  Some possibilities:    •
Reducing how hot it gets. Then it could stay on continuously
rather than cycling. But I don't think I have control over this.
• Putting dampening material in the heat sink, if it's the heat
sink that's making the noise.