No heat in honda odyssey

The heater fan runs fine. Cold air comes out of all the vents (defroster, floor, dash). There is plenty of coolant in the system, and my mechanic advises the engine is running at the correct temperature. The heater hoses at the firewall are warm/hot as if coolant is flowing through. Flushed the heater core (but that didn’t fix the problem). My mechanic now wants to drill some holes in the duct work to see if there is a mouse nest or some other obstruction. Thoughts?

What year is this van??

DRILL holes??? WHAT ??? No !!! Yes it is most likley a stuck blend door (depending on the year a motor can drive it, or vacuum), but there is no need to drill holes to check this.

it’s a 2000

The mixing valve may have come loose at the cable. I’d find another mechanic because drilling holes to find a blockage isn’t professional in my opinion. If you really suspect mice I’d put a piece of food on the floor and see if it’s gone later. If so find a mechanic with a boroscope to look inside the ductwork. On some cars you can hear if the doors are working because they make a “whomp” sound if you work it hard.