Just bought a '88 sundeck trawler (Hi, Dave).
The shower in the aft stateroom works o.k. except the water comes out intermittently too hot and too cold, cycling very rapidly between the two as if in time with the pulsations of the pump.
I'm wondering if anyone else has encountered anything similar or should I just plan on replacing the pump?* Is it normal for them to cycle rapidly ? Are there some brands that are smoother ?
88' sounds like fun, congratulations!
It seems you pressure tank is water logged. (Wild guess)
If your pressure pump has a tank next to it with a pressure switch on top of it, the tank is supposed to be clear of water in order to have a volume of air that can be pressurised and act as a shock absorber of sorts. Air gets slowly pumped away with the water and the tank get's filled with water to a point that the pump reaches maximum pressure as soon as it starts, yet if you are using water, the pressure drops instantly and so the pump switches on and off again and again. No good.
Solution is simple, drain the tank. If it does not have a drain tap, you will have to undue one of the houses at the bottom. Make sure it does not leak when you tie it up again. Better to change the two bit of hoses and SS clamps whist at it. Good luck!