Prius Water Pump replacement

My 2006 Prius just rolled over 91k miles, and I took it in for the 90k check at the dealership. They completed the laundry list, and informed me that my water pump was leaking and needed replacement. I took it to a local and trusted mechanic to replace the pump, as his price was lower and the car is out of warranty anyway.

I haven’t been driving the car much since either shop worked on it, but I have a new problem: I cannot get high or regular heat out of the cabin vents, and the blower fan for the cabin is operating at very low power. I can hardly get half the air volume out of it.

Which mechanic messed it up? Could the water pump replacement disturb the cabin temp AND the cabin fan operation?

The dealership only changed the cabin air filter. The local mechanic only changed the water pump and associated belt.

It sounds to me like neither mechanic messed up. This is a completely unrelated problem. Cabin air filter replacement will generally allow better blower motor output, if any difference is noticed, since the blower has to push air through it. The water pump is a mechanical part of the engine and has nothing to do with the blower motor speed or output. You need to have the blower motor and resistor checked, and possibly have the body control module and climate control system checked if your car has electronic climate control (I believe all Priuses had this). The only exception would be if the engine was very low on coolant. That would result in decreased heat output, but would not cause any change in the blower motor speed.

Thanks, I really appreciate the input!
I am also wondering if someone simply left a rag in the cabin air intake. Plausible?
I checked the cabin air filter, which was clean as a whistle and properly installed. Someone told me that if the thermostat that regulates engine coolant gets bumped during water pump replacement the engine will run too cold and therefore be unable to provide heat for the cabin. (That doesn’t explain the fan output though.)
The system control is elec., and I will have the blower motor checked.
Thank you, again!

Follow up:
Turns out there were excessive air bubbles in the coolant, causing my intermittent temperature variations. The fan’s effectiveness is a figment of my imagination, according to Toyota. That could be true, time will tell!

Prius coolant tanks are particularly difficult to bleed of air bubbles, FWIW to future mechanics or owners who may read this.