Need some Help/Advice

[monarc]

Pull your thermostat and put under the hot water faucet then the cold water faucet. Should open and close. Calcium deposits will build up. A mild acid will remove the calcium, or replace thermostat. If you run the river a lot you will also get a gunk build up in the discharge tube. Remove tube and just take a coat hanger and rod it out like cleaning a gun barrel.
(Bar Keepers Friend is a mild acid cleaner you can use to thermostat)

[Tyme2fish]

A buddy had that problem and I straightened out a piece of bailing water and did the ram-rod trick up the tell-tale hole while on the muffs. A couple of minute pieces of gravel came out and the stream was restored.