Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: fouroureye on August 23, 2017, 03:14:52 pm

Title: U280 water pump - not turning on
Post by: fouroureye on August 23, 2017, 03:14:52 pm
Greetings,
hope this is a fuze
turn on water pump... click from each location
no pump action...

I am checking voltage at the pump now
Title: Re: U280 water pump - not turning on
Post by: Barry & Cindy on August 23, 2017, 05:13:41 pm
Water pump switches just controls a relay, ours mounted on bay wall behind white fiberglass cover.  Relay turns pump on & off.  Relay often clicks.  Find relay and measure voltages, and measure pump voltage.  If pump has good 12v & good ground and 12v turns on & off with switches, all switches & relay are ok, and problem is with pump.  What model pump do you have?  Does pump get hot?
Title: Re: U280 water pump - not turning on
Post by: fouroureye on August 23, 2017, 06:15:27 pm
Thanks Barry....

I hate to tell this.....
while I was measuring voltage at yhe pump.... I was also filing the tank. Turns out pump
WILL NOT turn on if water level is toooo low.

I'm embarrased :facepalm:
Title: Re: U280 water pump - not turning on
Post by: wolfe10 on August 23, 2017, 06:26:17 pm
John,

Have not seen that one.  How is tank level information conveyed to pump relay?

Would think with low water pump would run, but no water coming out.
Title: Re: U280 water pump - not turning on
Post by: red tractor on August 23, 2017, 07:17:04 pm
probably the incoming pressure kept was overriding the pump pressure switch keeping the pump from running.
Title: Re: U280 water pump - not turning on
Post by: wolfe10 on August 23, 2017, 07:25:36 pm
probably the incoming pressure kept was overriding the pump pressure switch keeping the pump from running.

Interesting point. 

With pump cut in pressure of around 23 PSI, can't see how fill pressure (tank VENTED) could approach that. 

Said another way, if potable water tank pressure approached that, you would have an EXPLOSION of the plastic tank.
Title: Re: U280 water pump - not turning on
Post by: red tractor on August 23, 2017, 07:27:25 pm
The pump is tied into the pressure line that is filling the tank so the pump is not reading tank pressure but incoming water pressure.
Title: Re: U280 water pump - not turning on
Post by: wolfe10 on August 23, 2017, 07:31:37 pm
Interesting theories on both sides.

As far as I know, the diameter of the water line "in" is the same all the way to the tank.  Can't see a big delta in pressure through the system.
Title: Re: U280 water pump - not turning on
Post by: red tractor on August 23, 2017, 07:34:40 pm
To help understanding of this issue think about what happens if you leave the tank fill valve open, and the pump will continue to run until you turn the fill valve off, so definitely incoming pressure will effect the pump pressure switch.
Title: Re: U280 water pump - not turning on
Post by: jcus on August 23, 2017, 07:44:32 pm
The pump is tied into the pressure line that is filling the tank so the pump is not reading tank pressure but incoming water pressure.
That is correct and either a solenoid or manual valve allows the tank to fill. If you open fill valve, pressure drops, [water is dumping into tank] and pump will see low pressure and run. If tank fill valve closed, pump will see shore water pressure and probably not run.
Nothing to do with tank level.
Title: Re: U280 water pump - not turning on
Post by: FourTravelers on August 23, 2017, 08:00:12 pm
Possibly had the fill valve only partially open? enough restriction to water flow (if high pressure 60 - 80 psi on the supply line from water source) that over 20 psi was at the pump?
Just a SWAG.................
Title: Re: U280 water pump - not turning on
Post by: fouroureye on August 23, 2017, 08:38:33 pm
Thanks Guys... I feel real silly.

The facts are as soon as I put some water in.. I shut evert hinges from the house offf, valve closed.. it worked.

Said another way, pump relay from each swithch.. clicked..no pump
. looked at monitor..E... filled for 5 minutes, still on E.. but water pressure ! Pump worked, FILLED TANK 

All is good, sorry to take valuable time...  ^.^d
john
Title: Re: U280 water pump - not turning on
Post by: red tractor on August 23, 2017, 08:48:57 pm
We are all always learning something new.