Got a perplexing problem with our TT water pump & don't know what's going wrong. I'll do my best to try to describe what's happening & hopefully, someone out there has an idea what we can do........ We have a Shurflow water pump in our 2001 Aerolite TT that we've replaced 2x (luckily under warranty) due to the fact that it keeps back filling our fresh water tank when it's in use. My husband had put a check valve (?) on the line, but if the pump loses it's prime, the pump doesn't have enough "suck" to get the flowing the water again. He thinks it might be because the check valve isn't one made by Shurflow (it's just a generic one we got at an RV store) so it isn't compatable with the pump we have. The check valve stopped the backfilling, but it's no good to us since the pump then can't draw enough H2O to get itself going. What can we do about this situation? Camping season is nearly here in OH & I'd like to find some resolution to this before we start out again. Thanks, in advance, for the advice!