2007 Tundra, Heater not blowing any hot air?

How difficult is it to replace the heater core?

 

I had a similar issue with a Sienna. Turned out the coolant was very low (dealer error). Once I put about 1/2 gallon of coolant in to top it up, the heat came back.

 

Definitely diagnose the problem before you dig out the heater core.

 

Doing any heater core is a pain in A. But questions first

1.) is there coolant on the passenger floor board?
2.) is the coolant topped off in the reservoir
3.) does the vehicle run hotter than normal
4.) is the coolant circulating in the system
5.) when the heater is turned do the fans blows?
6.) does the heater control switch have the correct ohms when turning it
7.) when the heater is turned on does the coolant valve open to circulate