I hope so... ours does that. But, I notice it most often when I'm outside near the water heater access door or the slide window adjacent to the water heater is open.
I might be able to hear it when inside near the water heater, but I don't recall that at the moment. Our trailer isn't here so I can't verify that. Sorry.
Sherm & Terry w/rescues Steve (std Poodle) & Eydie (min Schnauzer)
2015 Jay Flight 27RLS (Camped: 102 nights 2015, 90 nights 2016)
2006 Ford F350 6.0 PSD, Lariat, 4WD, CC, LB, SRW, auto., Camper pkg.