Water Pump Priming

[gbaldwin]

Forrest River Surveyor - MBS20

Have not been able to access water pump but have not tried too hard. Have trouble priming system when running from fresh water tank after arriving at campsite. I always fill the tank after arriving at the check in (community water source) before parking on my site. Ran pump on and off for hours and turning on and off faucets and HW tank relief valve before it finally primed and then ran properly all weekend. This took several hours of "playing with it" befor it finally took prime. Worried this might not be good for pump?

Driving home yesterday I am wondering, If I hooked up to "City Water"before leaving home for a few minutes..... and opened all faucets and HW tank relief valve to purge all air out of system, will this solve my problem with priming pump once I arrive on campsite? I dont want to fill the tank at home for the 2.5 hour drive.... extra weight .....

Will it actually purg air from within pump?

Should or can I run the pump for a few seconds while hooked up to City water? Will it help?

Like I said, my pump is not easily accessable; NOt 100% sure how I would best access it; Dont really want to. Especially if its a job I need to do every trip. Access might be from underpenning???? Im just wondering if there is an easier way or best process for priming this pump. It seems to be a problem for me on most trips where I use fresh water tank; and I do normally drain the fresh water tank after each trip.

Comments appreciated. GB

[palusza]

May still be in winter bypass, i never have to prime ours

[gbaldwin]

I have read that other places, but I have never seen or used a bypass valve for winterizing. 18 month old TT and I winterize with just compressed air on the water pressure side. My pump and any valve is apparently under the bed cabinets, or underpenning. Never accessed it.

I thank you for comments but not the issue in my case.

GB

[5picker]

Originally Posted by gbaldwin

Forrest River Surveyor - MBS20

Have not been able to access water pump but have not tried too hard. Have trouble priming system when running from fresh water tank after arriving at campsite. I always fill the tank after arriving at the check in (community water source) before parking on my site. Ran pump on and off for hours and turning on and off faucets and HW tank relief valve before it finally primed and then ran properly all weekend.

Driving home yesterday I am wondering, If I hooked up to "City Water"before leaving home and opened all faucets and HW relief valve to purge all air out of system, will this solve my problem with priming pump once I arrive on campsite?

Will it actually purg air from within pump?

Should or can I run the pump for a few seconds while hooked up to City water? Will it help?

Like I said, my pump is not easily accessable; NOt 100% sure how I should best access it. Dont reall wanat to. Access might be from underpenning???? Im just wondering if there is an easier way or best process for priming this pump. It seems to be a problem for me on most trips where I use fresh water tank; and I normally drain the tank after each trip.

Comments appreciated. GB

No, connecting to city water and purging the lines will do nothing for priming the pump.

The pump draws its water from the fresh tank. (or the winterizing port if equipped by turning a valve)

The city water is actually kept separate from the pump by the use of a check valve (built into the pump) to keep city water from backflowing through the pump and filling the fresh tank.

You either have the winterizing valve in the wrong position, (if equipped) an air leak on the suction side of the pump, (possibly from a frozen/cracked suction strainer) no water (or enough water) in the fresh tank, a pump that simply needs primed (often times opening a faucet with the pump on helps this process) or a bad pump.

[ben31]

What year RV?

[dbledan]

Did thos just start this spring? Did you have a hard freeze this winter?

Running city water would not purge air from behind the pump because there is a back flow valve at the pump that SHOULD stop water from going to the tank...they don't always work right.

May want to see if you can hear any air coming from the pump. I suspect there may be an issue with that plastic screen before the pump.

If you didnt remove the screen and empty it when winterizing it would have froze and perhaps cracked. Blowing it out would not remove the water because it is after the pumps check valve.

Best of luck and hope this helps!

[gbaldwin]

Thanks!! As said in OP, I dont know if I have a bypass valve or not? I can not easily access the pump. Not aaccessable without removing panels and I have never attempted to start doing that.... The pump eventually does always prime and once primed, it works properly the entire trip/weekend..... I just concerned with the fact that it sometimes takes a few hours of playing with it pumping air to get it to take prime. I see videos of ppla adding water to lines at pump but sinces I cant easily access my pump.... what a pain.

Thanks for you help and the diagrams.

[gbaldwin]

Travel trailer, 2016 FR Surveyor. 20.0 MB

[Flybob]

Blowing out lines does not remove water from the small filter on the pump nor the pump body itself. If you had a good freeze, it is possible the pump body or the small clear filter bowl froze and cracked.

[gbaldwin]

Originally Posted by ben31

What year RV?

2017

[gbaldwin]

[COLOR="Blue"]You either have the winterizing valve in the wrong position, (if equipped) an air leak on the suction side of the pump, no water (or enough water) in the fresh tank, a pump that simply needs primed (often times opening a faucet with the pump on helps this process) or a bad pump.

1) valve position - Think not because I have never seen such valve (or pump) and no one else has done any work on unit. Once pump catches prime, the pump works great, turns on/of when called for.....

2) Tank is full. This happens about every I take a trip w/out city water (using tank) Just takes a long while to catch prime.

3) turning on pump and openiing faucet is the only way I can prime pump without removing panels... to access pump. This would be a pain. Hoping for an easier way.!!

[cavie]

If you don't by pass the WH and drain it in the winter your gonna be buying a new water heater.

[babock]

Originally Posted by gbaldwin

This would be a pain. Hoping for an easier way.!!

You either have an air leak between your pump and the tank or you need a new pump.

[babock]

Originally Posted by cavie

If you don't by pass the WH and drain it in the winter your gonna be buying a new water heater.

Not if you drain it. The bypass is only if you are running antifreeze through the system.

[gbaldwin]

Originally Posted by dbledan

Did thos just start this spring? Did you have a hard freeze this winter?

Running city water would not purge air from behind the pump because there is a back flow valve at the pump that SHOULD stop water from going to the tank...they don't always work right.

May want to see if you can hear any air coming from the pump. I suspect there may be an issue with that plastic screen before the pump.

If you didnt remove the screen and empty it when winterizing it would have froze and perhaps cracked. Blowing it out would not remove the water because it is after the pumps check valve.

Best of luck and hope this helps!Attachment 200419

NO, DID NOT JUST START.... seems to happen each time I tak a trip using only fresh water tank for water. sometimes catches prime right off, other times seems to take hours. I am just trying to find a sequence or best method of getting this prime to take without dry pumping of the pump? Concerned it might damage. and a cant access pump w/ut removing panels....

[gbaldwin]

Originally Posted by cavie

If you don't by pass the WH and drain it in the winter your gonna be buying a new water heater.

Well I do drain the HW tank, then pressureize with air and blow out moisture at each faucet and HW relief valve.

[5picker]

No procedure is going to eliminate "seems to take hours" of running the pump to prime it.

You need to find the issue and it sounds as though there is some kind of air leak on the suction side of the pump. I had a suction leak once that was as simple as the vibration from the running pump loosened the suction strainer fitting.

[5picker]

Originally Posted by gbaldwin

Well I do drain the HW tank, then pressureize with air and blow out moisture at each faucet and HW relief valve.

As mentioned, just blowing out the lines WITHOUT disconnecting the pump to drain ... OR... ingesting antifreeze into the pump-suction/strainer, DOES NOT remove the water from those components.

It is entirely possible the suction strainer plastic housing is cracked or even the pump inlet housing.

[gbaldwin]

Originally Posted by babock

You either have an air leak between your pump and the tank or you need a new pump.

OK, so it does seem to take from 30 min - 2 hours of running the pump on and off from switch, randomly opening and closing faucets, and finaly getting good water flow and pump works from then on the entire trip as it should (3 days) , pump only running when call for water.

Does this make sense? My concern is the time it seems to take to prime.... pumping just air, and spitting small amount of h2o before priming.... Is this bad for pump.

[Flybob]

If the WH is empty and the pump is working properly you should have a good flow of water in less than 5 minutes. Anything longer is an indication of a problem.