Heater core is stopped up or thermostat is stuck open.
thermosat could be stuck open or low coolant or heat control cable could be broken
pee on it
it could be your thermo stat
It could possibly be a clogged heater core
The air-condition belt on a 2001 Honda Accord also controls the heat. When the belt needs to be changed the ridges on the belt will show wear.
A block heater for a Honda Accord helps to quickly raise the temperature of the car to the proper heat level. This allows for a quicker engine start-ups.
radiator hose needs replacing. use and heat will cause hose to collapse when worn out
Could be running backwards....reverse the leads and see if it stays cool running the opposite direction.
The air mix door is stuck in the heat position
CHECK BLOWER MOTOR, AND HEATER CORE BOTH INSIDE THE CAR UNDER THE DASHBOARD
A thermostat
101 problems could exist but most likely it was caused by a poor transmission design. There are hundreds of complaints on file with the NHTSA about the sudden failure of this car's transmission at highway speeds. The cause is related to an issue that required a 2004 recall of several Honda models for excessive heat buildup and gear lockup. The resulting fix put in by Honda slowed the rate of failure, but did not address the underlying cause. You should have the transmission inspected by a specialist. Most shops will not charge you to inspect it if you have service done, but be prepared for a "transmission failure" diagnosis.