There's a vacuum actuator that closes the water valve. Vacuum closes it so no heat would mean the actuator works, but the valve might be stuck closed. A test would be to feel the left side near the back of the glove box after you've driven it for a while, if you're getting water it should be warm, the water line runs right by there (or you could take the glove box out.). The valve is under the plastic at the base of the windshield on the right side. You can kind of see it through the vent slots.

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5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)