I have never replaced the heater core hoses which on my coach, are rubber hose from the engine to the heater core. I had my mechanic check them and he said they look great. No dry rot at all. Should I replace them soon even tho they look good?

My philosophy on all engine hoses with unknown birthdates pre-2005, an arbitrary cut-off, is, to replace them. It seems hose performance has really increased now and my old 4 year faith of pre-1990 has increased to complacency.
Hoses and fluids are always more expensive on the highway.

Good reading here called heater hose nightmare