[roadappels]

We had a similar problem on our 90 this past summer and Michael Day and I trouble shot a couple of hours and it turned out to be the anti-scalding valve...it was a delta faucet though. Rudy sprayed some anti-corrosion spray on the valve and we proceeded to move it enough till it was operational...not sure but do you have a hot, cold and then the third valve? If so, I bet that valve is corroded.

B