As overheard on the phone one winter's day

"Hi, I'm calling from the office in the basement, and there's this strange noise..."

"Yes?"

"Well, it's coming through the wall, this really loud ka-thunk, ka-thunk, ka-ka-ka-thunk sound."

"Oh yeah, that's the heating."

"Right, I see, the heating. So you already had this reported?"

"Yeah, it's been making that noise for ages."

"Does it always makes that ka-thunk, ka-thunk noise, the heating?"

"Just when we turn it up. The people upstairs were complaining that it was too cold, so we turned it up. Now it makes that noise."

"So - well, is there anything that can be done then?"

"They've already had a look at it."

"Right... and so is it going to be fixed?"

"No, we'll just wait till we get a few more complaints about the noise, and then we'll turn it down again."

"I see..."

Silence.

"Er, ok - thanks. ... Bye."

"Bye."