House Water Pump needs assistance priming

[ILFarmer2020]

Class A system, 1999 model.

The only way I can get the pump to prime is by hooking up a garden hose to my "Sanitize" hookup, run the water very slowly and turn the pump on. It's my understanding that the system is supposed to self prime and not need this extra step...

Now that we are sanitized and ready to go (Leaving for big trip Mon 7/6), I simply intend to leave the system alone (running/standby) and not lose the prime. Once I help it prime it works as it should.

This is a Fleetwood 40VS and I have read the directions, but the directions are a little foggy on the different valve settings especially for using the on board water supply tank. When the instructions discuss using the on board water tank, it simply says "turn pump on". This tells me it should self prime and not need extra help..

Any ideas are welcome. As my username indicates, my profession involves many mechanical tasks, including spraying, pumps etc, but these small systems are still new to me.

Thanks for any advice! We are excited about our first trip next week!

[wa8yxm]

Pumps are supposed to be self priming.
My suggestion is FILL the on-board tank full.
Turn on pump
Stand on toilet flush pedal (About the biggest water sucker with the possible excption of the shower head)

This releives "head pressure" and makes it easier for the pump to suck water.

Also make sure any pre-pump valves are properly opened or closed as needed.

[Bipeflier]

Since it is a 1999 I suggest rebuilding the pump (20 minute job) and opening a faucet to relieve pressure on the discharge side when trying to prime the pump.

[Harvey51]

I had to prime the pump after every refill of the fresh water tank. It was easy - a syrup bottle with small cap filled with water, squirt into the hose used to pull antifreeze into the pump.

I got tired of that and went to an RC parts store with my story and the clerk sold me a new diaphragm for less than $10 - haven’t had to prime it again. Easy to install.

[wnjj]

They can go bad. The pump in our camper worked fine for several years but now will not prime unless the tank is completely full. Once I prime it by forcing water into it by blowing into the winterizing tube with water in it, it will hold prime fine. It doesn’t leak back or run unless water is used. It otherwise works perfectly. I’ve cleaned the diaphragm twice and now just have a new pump to install.

[enblethen]

Make sure the fill valve is closed/

[mleekamp]

When we first got our motorhome, after 20 years of a travel trailer, I was a bit confused on the valving system of motorhomes. In short, trying to winterize my unit, you screw the hose to the inlet, and let the other end in the bottle of pink stuff....problem was, I had the valving in the wrong position (NORMAL) vs (WINTERIZE), where it pulls from the bottle. Bottom line: After 30 mins of trying, I realized I was not getting suction due to valving position.

The pump should self-prime. But, only if your water heater bypass is closed (as kellem said), and your other valving in the correct position.

Usually, there is NORMAL, WINTERIZE, SANITIZE, CITY FILL, and CITY WATER, or similar. You may have a few more/less. As I said, I had my valving pointing to NORMAL, which meant it was trying to pull from the tank, not my bottle. In your case, you may have had valving pointing to something else?

BTW -- When I think of Bushnell, I think KITCHEN COOKED POTATO CHIPS!

[kellem]

I've not heard of a water pump requiring priming before operation.

Does the system have good pressure once primed ?

Hot water bypass valve closed ?

If you have a pump converter kit used for winterizing, ensure that the valve is fully closed.