Pump when hook up to city water

[DanLefoot]

Hello Folks.
We are hooked up to city water In Breckenridge, Co. The water pressure is the weakest in my experience. If I turn the pump on pressure is much better.
Does doing this create a problem? With the the pump on and connected to city water does the water in the coach come from the tank or both?
Thanks
Dan

[wa8yxm]

Ok some background.
Motor homes have one or two water pumps (The one I saw with two also came with a price tag.. that had two COMMAS in it. like 1,500,000.00 dollars)

The owner said if you turn 'em both on it will knock your hat off in the shower (He's a "Country-Cowboy-Gospel-Performer by the way. Actually rather good I bought one of his CDs)

Most pumps are set at 45-55 PSI

Many parks are as well but some parks. well 120 PSI is not unheard of (Common where I park winters)

So you use a regulator.
Regulators come in basically 4.2 flavors

1.1 A cylinder about 3/4 inch Brass or plastic male hose fitting on one end female on the other may or may not be "Adjustable"

1.2 Like the above but with eithr "Wings" on the body or a bright (usually) plastic GRIP on the female end. this is often called "HIgh Volume" or "High Flow"

These are junk do not purchase them. Oh I use one for a very low-flow project but they are not useful They do Reulate but 1GPM if you are lucky on the high-flow Not good for a shower.

2: Sur-Flow (A Watts Company) This one is sometimes built into an RV. or you can get an "inline" the actualy regulator is identical in either case.
New I give it about a 9.. I can take a shower with only slight loss of pressure. Not sure how they hold up as they age but appear a kit may be possible.

Valterra Adjustable ... This one gets good reviews from others. I've never used. I recommend it for consideration.

"Whole House "inline" by Watts or Zurin (have used both) The two I have are 3/4 Inch (Turns out that's cheaper than 1/2 at least the Zurin) with garden hose adapters threaded into one and sweated on the other.

These are solid 10's when new. but like the joke about Bo Dereck aging over time 9-8-7-6 But in both cases rebuild kits exist.

What is a 10.. I set my Zurin for 50 PSI static (no flow) Opened the shower full and the needle on the Gague.. Frozen in place at 50 PSI.

So. where does this get us with the pump.

I strongly recommend a regulator (See 120 PSI) if yours is a "low flow" fill the on board tank and when you need High-Flow (IE Shower) Turn it on.

What I do (I no longer use a regulator for house water even at the 120 PSI park)

I use a low flow for a MISTER I have.. 1/2 gallon per hour is well within the regulator's capacity 🙂

But for all other use The high pressure park also got hit with high chlorine a few years back.. Water tasted of bleach. So I hit on the idea of filling my 80 gallon fresh tank and letting it set for a few minutes (The book (Caring for fish tanks) says it don't take long) and sure enough the book was right.

Then I discovered (After my wife died) I can go up to 4 weeks on 80 gallons. So since summers I stay at two parks , one with better water, I tank up at the good park before I leave. 2 weeks in the not so good water park, and back Tank up again after a few days and just before I leave.

Same with Dumping.. I dump in the Good water park

WHY? 1/2 the hookups and unhookups I don't even mess with hoses at the bad water park.

[DanLefoot]

Thanks everyone.
Looks like running the pump while hooked up to city water empties the water tank.
Dan

[2oldman]

smarty wrote:
We never use our water pump nor do we put water in the fresh water tank

Am I correct in assuming that the pump would not work similarly for us due to the fact that our freshwater tank is empty?

You never stop for a meal and need to wash your hands? Never need to use the bathroom on the road? You should try it, very handy.

You do not want to run your pump (for very long) sans water in the tank.

[ppine]

Thanks to Old Biscuit for the explanation.

[Lwiddis]

"We never use our water pump nor do we put water in the fresh water tank"

Why? So many beautiful dry campsites in the West but you have NO water.

[Old-Biscuit]

City Water Inlet has a 'check valve' so when using pump water does NOT flow backwards theu the city water inlet connection...otherwise when using pump the water would leak out the inlet

Pump has an internal check valve so when using city water source the water doesn't flow backwards thru your pump

With pump switch on (and water in fresh water tank) the pump will NOT run unless the RV Plumbing System pressure is lower then the pump pressure switch Start set point......
With city water connected and pump RUNS the system pressure is low enough for pump to supply water demands and city water flow is static due to inlet check valve going closed due to pump discharge being hogher then city water source (plus inlet check valve has a spring to assist in closing it)

So either City water supplies the RV Plumbing System OR the Pump sucks water from fresh water tank and supplies the RV Plumbing System


Basic RV Plumbing System

[Roger10378]

The water usage will not split between the city water and pump, it will use water from the higher pressure source. So you will have to add water to your tank from the city if you are staying very long.

[Johno02]

We keep water in the fresh tank, and use it, even for drinking sometimes. When connected to shore water, we also use the pump occasionally to increase pressure and flow while showering. It is a big improvement for the shower.

[camperdave]

Good question about where the water will come from! I've wondered the same, we usually run off the tank/pump only, but lately I've been using the city water hook up more.

I still keep the fresh water tank full, and turn on the pump when showering (other times, who cares if the water pressure is low?). I have not tracked how much water comes out of the tank, I assume it's a split of both depending on the pressure differential.

and smarty, you are correct your pump will not help you out if the fresh water tank is empty.

[ppine]

The pump runs off the tank. Don't turn it on unless there is water in the tank.

[smarty]

We never use our water pump nor do we put water in the fresh water tank

Am I correct in assuming that the pump would not work similarly for us due to the fact that our freshwater tank is empty?

Gonna try this tonight and see

[Bobbo]

RoyF wrote:
I'm not a hydralics expert, but I guess that if pressure from the pump is greater than pressure from the city line then the pump will send water not only to your tap but also back into the city line! (But maybe there is a valve in the city line that prevents backflow.) Have you tried turning city water off and using the pump only?

I think that you had better keep your freshwater tank topped up, even it takes hours to do so.

There is a backflow prevention device at the shore water inlet. Otherwise, every time you turned on your pump you would pump water down the side of the RV. (Mine failed one time when we were on a 6 week camping trip and doing a lot of boondocking. My temporary fix was to get a garden hose shut-off and screw it into the shore water inlet, then turned its valve off. Worked like a champ. When we got home, I replaced the backflow preventer.)

To the OP: There is absolutely NO problem with turning on your pump when you need more pressure. As far as where the water comes from, that depends on the shore water pressure. The lower the shore water pressure, the more water you will get from the tank.

[RoyF]

I'm not a hydralics expert, but I guess that if pressure from the pump is greater than pressure from the city line then the pump will send water not only to your tap but also back into the city line! (But maybe there is a valve in the city line that prevents backflow.) Have you tried turning city water off and using the pump only?

I think that you had better keep your freshwater tank topped up, even it takes hours to do so.

[gbopp]

I do it when the pressure is low. No problems.