water Pump

[Videocrafters]

Every 2 or 3 hours my water pump comes on for a split second. I have no water running anywhere. I suspected a minor leak, but I have checked all the water lines that I can find and they are perfectly dry.
So is this normal to have a split second pump power up every few hours or is there a problem that i have not found.
Certainly not a big deal, but....

[davidmurphy02]

That is pretty normal, the system loses a bit of pressure in that amount of time and it does not indicate a leak. We usually turn off our pump when we're not using it, and certainly overnight.

[gbaglo]

Not exactly a solution, but I only turn the water pump on when I need water. If you do develop a leak while away from the trailer, and the pump is on, you might have a flood.

[HABBERDABBER]

That's your pressure sensor switch working. There is some in-line pressure loss somewhere.....not a leak, but temperature change, expansion/contraction of water volume or some other thing. It's dealing with the whole water system.....water heater especially included.

And YES, turn the pump off when away. Oh, remind me often to do the same.

[davidmurphy02]

Originally Posted by gbaglo

Not exactly a solution, but I only turn the water pump on when I need water. If you do develop a leak while away from the trailer, and the pump is on, you might have a flood.

Not to mention a mischievous cat....once in our old trailer we were in the dinette and heard a rush of water in the bathroom. We kept the litter box in the bathtub, and Blossom had been messing with the faucet and turned on the water. Turned that litter box into one big clump.....we always made sure to turn the water off when we left the trailer.

[MVA]

We have seen the same. Two thoughts: (1) contraction of water volume due to reduced temperature (is pump oscillation correlated to time of day?); (2) cheap pump check valve leaking minute volume of water back into fresh tank side of pump.

Order of magnitude calculation for (1) - The thermal coefficient of expansion of water is 210x10(-6) 1/C. Assuming about 7 gallons (5 for WH + 2 for piping) or 28 liters of water in the pressurized system, then for each degree C, the volume change of the water is about 6 cc for each degree C. 6 cc is about 1.2 teaspoons. So a small temperature drop could cause the pump to quickly turn on/off. Check my assumptions & calculations.

For (2), it IS a cheap pump....

2 cents

[gbaglo]

Originally Posted by MVA

Assuming about 7 gallons (5 for WH + 2 for piping) or 28 liters of water in the pressurized system, then for each degree C, the volume change of the water is about 6 cc for each degree C. 6 cc is about 1.2 teaspoons.

How many amps is that in watts?

[bborzell]

ETI has a video showing how to dial back the pump to lessen the frequency of unneeded/unwanted pump grumbling.

[sunrisetrucker]

Originally Posted by Videocrafters

Every 2 or 3 hours my water pump comes on for a split second. I have no water running anywhere. I suspected a minor leak, but I have checked all the water lines that I can find and they are perfectly dry.
So is this normal to have a split second pump power up every few hours or is there a problem that i have not found.
Certainly not a big deal, but....

We had the same problem so I installed a new pump and that fix it. There is a oneway check valve in the pump and my guess is that it was leaking back into intake side of the pump.