Class A Motorhome fills freshwater tank on city water
A Fleetwood Southwind owner reported that when he connected to city water, he could hear the freshwater tank filling!
The customer was located in Pismo Beach, nearly 300 miles south from me, so he arranged to fill the freshwater tank, remove the city water connection, and use the onboard water pump. This helped him continue the family camping trip and I could repair the fault when I made the trip south to central California.
Inspecting the fault on arrival, it firstly appeared that the check valve at the city water inlet was not functioning. While this did not seem to be the cause of the original fault, the first step was to renew the inlet water check valve. It was very corroded and could have leaked when using the freshwater pump system.
The diverter valve was also failing and it was totally seized. The valve handle would move between ‘Tank fill’ and ‘City water’ but the actual valve was locked in ‘Tank fill’.
These diverter valves are a three-way fitting. This means that the water from the inlet can be diverted to either tank filling or switched to supply city water pressure directly to this Class A motorhome’s plumbing.
There was no simple solution to this today. I contacted several local suppliers and drove to various specialist plumbing supply companies. No one had anything similar to the three way ball valve I needed. Online suppliers had nothing in stock either. So I had to develop a bypass system that also made it easy for this family to use. It was best to design the system so they used it as normal, but operated differently behind the basic valve handle.
The solution came from a simple on / off one half inch ball valve. City water would flow to the internal plumbing, and opening the new ball valve would also supply water to the freshwater tank for refilling.
The working space was very tight and the plumbing complex was intermingled with 120 volt cables! This required a full shut down of all electrical to operate safely.
On the back of my pickup, I constructed a rather complicated piece of plumbing using brass Pecs and blue cold water pecs half inch pipe. The system worked! After quite some trial and error, the system worked successfully, but for some reason water pressure was poor inside the coach. What was the problem?
Class A motorhomes are very complex and the engine, frame, and drive lines create many obstructions in locating faults. After nearly an hour of searching through all the hatches, crawling underneath the frame, and looking for a kink or obstructions in the plumbing, I discovered a whole of house water filter! This water filter had not been changed in years! I just happened to be carrying a spare filter and full water pressure was returned.