Water Pump

[MadMax]

A small problem – DW just finished having a shower and she told me the water seemed to be running out (boon docking). She told me this several minutes after she finished and then came outside to advise me. I said that – yes, it was getting low so it probably ran out. When I walked closer to the trailer I could hear the water pump still trying to pump water so immediately went inside and shut it off. DW didn’t realize this was necessary.
Long story, short - I refilled the holding tank, turned on the pump again and opened each tap to let the air out. After this was done the pump shut off automatically because all the lines were again charged.
Now when I turn any tap on it seems to take longer for the pump to kick in even though the water comes out right away. I’m not complaining but now when I shut off the tap it takes longer for the pump to quit and it seems to be a lot louder than before.
Any ideas why this changed? :confused

[Maxzd]

My assessment is if you are boondocking your battery voltage is getting low. The pump will continue to work with a low battery but will take longer to cycle. The pump usually is noisier with a low battery as you describe..

[JRTJH]

I agree, low battery voltage will cause your problem, also, you may have lowered the water level in your water heater causing a bigger air gap. That bigger air volume takes longer to compress than water, so the pump will run a bit longer until the system pressure reaches the pump's cut off switch setting. I wouldn't worry about it, keep camping and when you plug it into shore power at home, you'll probably find that it works as normal again.

[warsw]

It sounds to me like you still have some air left in the system. If you do it will start acting more normal as you use it and work the air out.

[diugo]

The dry pump pumped some air into the hot water tank. This air forms a bubble at the top of the tank, and compresses under full pump pressure, just like an accumulator. The air bubble will disappear after a few days as the air is slowly absorbed by water. Until it does, the pump will take longer to kick in and run a bit longer as it compresses the bubble.

[MadMax]

Thank you all for the good info. I am plugged in now so will just wait and see if the problem clears with use.