Water pump replacement

LenS · 05-07-2015, 12:31 PM

Replaced my sink Westfalia style water pump today. 15 year old one was still working but the pitch of the sound it made would vary once and awhile (bearing??). Rather then have it go bad on the road I put a new one in and will keep the old one as a spare part.

Here are some pics of the old and new pump. Took old pump apart for an inspection and took some pics. New pump w shipping cost $45.

I do like this Westfalia pump because it draws less than an amp when on and has a 1 gpm flow rate. Lets us keep good control - less waste- over the use of our 18 gallons un-pressurized fresh water.

New pump

Viva · 05-07-2015, 01:39 PM

Edited to add: I searched the part number and I get it now. So this is a pump that you "switch on" at each faucet instead of just opening the faucet as with a "whole rig" water pump. Just curious: Do you still have "regular" faucets then? Or are they simple pipes that let the water flow out (like a Fynspray spout, for example)?

Since I don't think I can totally delete the post, I'll leave the rest here for the sake of discussion of options, although I think I understand it now.

*****

I'd been thinking of putting in a "manual" foot pump (what I'm used to from boats) for the quiet, and the natural water conservation they provide, but that's somewhat problematic due to the layout of certain fixtures in my rig. So I'm intrigued by this low-flow pump, but not quite sure how it works as compared to the "typical" on-demand type.

Optionally I was looking at the Whale Watermaster FW0814, which is the on-demand type, but only 2 gpm (smaller than usual). That would be a "system wide" pump.

Anyway, as you can tell I'm not totally clear on how the type you have works - if you have any words of wisdom/explanation that would be great. I tend to like things set up in a more basic way, and don't mind feeling like "I'm camping" (vs. the type of RV-ing where people don't want to feel like they're camping).

LenS · 05-07-2015, 02:12 PM

It is a non-pressurized system. The pump moves water only when it is powered by a switch at the sink.

I replaced the cheap unsealed rotary switch that came with the faucet with toggle switches with water resistant boots.

You can see the black toggle switch for the faucets in the below pics.
The new pump I just installed has a measured flow rate of 1.2 gpm at about 0.8 amps

rockbender · 05-07-2015, 05:12 PM

Ah - I see. A separate pump for each faucet! I like the small size and low flow / low draw of those pumps. Unfortunately, I plan to run my water through an instant hot water heater which I think requires a bit higher flow to operate correctly. Since these are not pressure pumps, can you effectively put your finger over the end of the faucet with little pressure build up? Would it hurt the pump if you had a faucet valve (ie, run the pump against a closed faucet)?

I never looked that close at how you have your outdoor sink setup - I really like that. It is a clever use of that space where you store your hose too! I've been eyeing that void wondering if I shouldn't try to make use of it somehow.

LenS · 05-07-2015, 05:30 PM

I ran a clear hose off of the pump once and I believe that 3 feet was the highest the pump would push the water. That would indicate 1.5psi of water pressure. So you should be able to put a finger on the end to stop the flow. Restricting the pumps flow should up the load on the pump motor. No idea if that would shorten the pumps life. Must be a fair amount of leakage around the impeller because the pump is not self priming.

Viva · 05-07-2015, 06:26 PM

Thanks for the additional pics and info. Besides, I never tire of looking at your van and its clever outfitting

boywonder · 05-08-2015, 08:22 AM

That little pump is a centrifugal pump (simple little impeller).

Centrifugal pumps can be run "dead-headed" e.g. no flow without any problems. These are considered positive pressure pumps.....which means that you can vary the downstream restriction and the pump will (roughly) put out it's rated pressure all the way down to zero flow. Of course the motor may not be rated for continuous duty but that's another discussion.

The other common pump type is piston style which are positive displacement pumps. These cannot be operated dead-headed without a bypass/recirculation loop. They usually will either stop spinning and smoke the motor or break something internally since liquids are incompressible.