Honda Repair: 91 Accord No Heat, replacing a water pump, control cables

Question
I just took my 91 Honda Accord (220K miles)to my mechanic because of little heat coming out of the defrost/vents, I think he said it was about 120 degrees or less (290 at the engine?).  He checked the thermostat and heater core and thought both to be fine.  He says the next step is replacing the water pump.  Before I decide to go ahead, is there anything else it might be?

Answer
The first thing you should do is go ahead & replace the thermostat & make sure the coolant is properly bleed. If a thermostat is malfunctioning, you may have issues with heater performance. A thermostat should cost less than $150.00. Replacing a water pump & timing belt will cost over $500.00. Also, make sure the hot water valve is adjusted properly. It is common for temperature control cables to get worn out over the years & not close or open the hot water valve correctly.