fresh water pump keeps running

[m5jaxi]

 Filled the fresh water tank, and opened up all the water lines untill water flowed good (no sputtering).
When I turn off all spigets the pump keeps running. I have a 1989 Chieftain. Can anyone help me?

[Oz]

First thing is to check all around anywhere there are water connections to see if there is a leak.  On-demand pumps are designed to continue to pump as long as there is no back-pressure, which means: all the faucets are shut off, the water heater is full, and the toilet isn't running.  Any leak in the plumbing system will cause the pump to keep running.  If it's not a leak, then the pump is faulty and if keeps running, would either cause a line or connection to burst somewhere or blow the pump.

Be sure to check areas which are obscure, where splits in the plumbing are located, such as around the shower/bathroom sink, kitchen sink, etc.

The first time I used my on-demand pump, I could hear it running, but couldn't find the source of the leak until I saw water seeping out from under the wall next to the shower.  It turned out there was a pex tube connection there which had popped loose.  What a mess!