Pressure side causing pump to not prime?

  • Last Post 28 March 2023
JWK1251 posted this 27 March 2023

My pump wont stay primed. If I disconnect the pipes anywhere downstream from the filter and/or the heater it will stay primed (so it would seem that the pump is ok). But when the loop is closed it will stay primed for anywhere from 10-120 min and then loses it's prime. Can too much resistance on the return/pressure side cause a lack of prime?

InyoRich posted this 28 March 2023

You can lose prime from a lack of downstream flow from the pump (dirty or undersized filter, clogged line, or plumbing that is too small to handle the flow).  That can cause the water to cavitate and lose prime.  

Has something changed in your system (new pump, new filter) or is this a new installation?