Originally Posted by DMoneu
Super-newbie owner here of a 2015 MBS Sunseeker 2400S.
Have successfully camped 2 weekends w city water. This weekend having to use fresh water and pump at a state park and having problems.
I filled the fresh water tank until overflow valve had water coming out of it. Overflow valve continued to dribble water for several hours. Inside tank sensor says fresh water tank is empty. Is this normal? Who do I trust?
Also, water pump seems to run continuously when I turn it on. And faucets, especially kitchen sink faucet provides lousy pressure with lots of air in the line. Any tips?
Finally, how do I drain the fresh water tank? Having trouble finding the valve to do this when I leave here.
I think you just have a issue of pump not priming which is very common. For me especially first use after tank has been drained/winterized.
First, if you ran water into tank for 10-15 maybe 20 minutes before the overflow started, my guess is that you do have water in tank. But we have air trapped in the system and pump is trying to force that air out..that is spitting out of your faucet.
If your water heater was not full of water, this is about 6 gallons that must fill from your fresh water tank. That air has to be purged out of the system as well as the air in your H and C water lines.
When filling fresh tank, I normally hook up the water first to the city water connection and open each faucet to let water fill the system and purge air out. I then fill the FW tank. If you have water available you might try this.
The light indicators for fill level are quite frequently not reliable. If you are confident that you did get 15+/- minutes of water flowing into the tank, I would turn pump ON, let it run, and alternate faucets throughout on both hot and cold side and air normally will eventually be forced out and pump will prime. The outside shower is also a place to relieve this pressure; the relief valve in the hot water heater cabinet should also be opened a few time to relieve any air trapped here. It often takes 10-15 minutes for mine to finally prime but I dont think it will damage anything to let it run. Its a trial and error process but my pump eventually does prime and all is good.
The drain is under the rig near the fresh tank. If it or a low point drain is leaking, id try tightening it up. Normallly have a 1/2 inch cap on them; sometimes a 2way valve. All I have seen this drain is a single white pipe with a cap and not all that easy to see.
Of course when you used your city water in the past, the pump never ran. Just city water pressure forced water thru system.
There is a bypass valve right at your water pump if you have found it. If it is not fully open, this could be part of the problem but my best guess is it's just a pump priming issue. Patience!