Water Heater Barely Heating

Usually the Bypass valve is a 1-2 or 3 valves Now i've seen them in various places but .. Find the back side (inside of the RV side) of the water heater. FOLLOW the lines from the water heater.

IF you have a single valve (I doubt it) you will find it, it is a 3 way valve and there will be a check valve in the HOT line at the heater (The 3-way is in the cold line)

2 valves one in hot one in cold and a pipe between them

3 Valves (What I have) the lines are "T" fitted before they get to the inlet and outlet valves and then another "Bypass" pipe has a valve in it

USE means the inlet and outlet valves are open. bypass closed

Bypass reverses that

THe valves often have Oval shaped handles and if the LONG AXIS is along the pipe that is usually (but not always) OPEN.

SUSPECT 2: The Showers.. Mixing valve open and head cut off closed. Same symptoms.

where would the bypass valve be located? Do you mean the hot water tank bypass that I close when winterizing to avoid antifreeze getting in the hot water tank?

Bypass valve (as stated)

or

Inside or Outside shower valve open with hand wand closed (hot and cold mixing)

Toddupton wrote:
Bypass valve is open

Yep. I believe that is the answer

Bypass valve is open