New one to me: City H2O connection overfilled fresh tank

[C&G in FL]

You could also add an inline check valve to the output side of the pump. Click on or copy and paste the link below; this one is plastic. It will address any check valve problems. The best thing is you do not have to remove the pump to replace it if it goes bad. Two minute operation to change if you are slow. ShurFlo check valve replacement is 20 to 30 minutes plus frustration. And before anyone questions this modification.......Yes, I checked with ShurFlo and they confirmed it is permissible to use them on their pumps. You will need a small fitting to convert one end of the check valve to female threads.

https://amazon.com/Zurn-Q2500-Mpt-Ch.../dp/B002UC2VTY

[Jill]

Thank you for the help. The problem is finally fixed. We were out all day yesterday and I thought it worthwhile to try the 5 step fix again before trying to clean the pump. This time I repeated the steps 3 and 4 (pressurize, release pressure) 3 times (3 times a charm right?) before reconnecting the water. Not sure if it's what I tried today or the fact that we used the pump for a day that solved the problem. Either way I do think the cause was somehow related to the fact that the trailer sat unused for months through a hot Sacramento summer as we had this problem last year first trip out after the hot summer. Last year though the 5 step fix solved the problem right away.

Anyway thanks again for the help. And we intend to to get the check valve that Carl suggested. And maybe camp during the hot summer instead of leaving the trailer to bake in storage!