Water pump (one more time)

[Gregory OConnor]

David, I wonder if head pressure is the cause of the fluctuating hot
water issue. Because after 1/2 the tank of fresh water is up, the
problem stops.?????????? If the tank outlet to the pump is on the
bottom of the potable tank?????? the hot water tank is pressurized by
cold fresh water via the pump and it may flow in too fast and the
pressure control is effected by the loss in psi on discharge side
with the higher then able gpm flow. If there is a valve on the inlet
to the Hot water tank you can try and close it some to restrict gpm
flow and psi loss. or just pinch it with a vice ( if soft
tubing)??????????

GregoryO'Connor
94ptRomolandCa

--- In WanderlodgeForum@yahoogroups.com, David Brady
wrote:
>
> I called Shurflo and they specified that the pump should have
> at least 18 inches of elbow free tubing both at the inlet and
> at the outlet. I have much more than that. I don't use any strainer
> at all. All tank water is filtered as the tank is filled, so I'm
> thinking that the strainer isn't necessary. With the original dual
> fuel pumps both used strainers, and the strainers were always
> spotless. To quiet the pump even further I mounted it using a
> Jabsco vibration pad kit, part number 43990-0058. These legs
> provide much more vibration dampening than the original
> Shurflo legs. The pump is virtually silent. I do have aquahot.
> What I experience, especially on hot water, is: as the hot water
> is turned on, the pump ramps up, stops, ramps up again, stops,
> and again. It may do this half a dozen times before it settles down.
> In the shower, this turns in to variation in temperature. Since the
> cold water pressure is fairly constant, the cold water flow stays
> the same, but the hot water oscillates. The temperature varies from
> say 115 deg F to 120 deg F every second or so. Very annoying.
> But then, after say half the fresh water tank is used up, everything
> works properly. Maybe another call to Shurflo is in order.
>
> David B
> '02 LXi, Smokey
> NC
>
> Pete Masterson wrote:
> >
> > Reading the installation instructions with the pump, it cautioned
> > about isolating it from vibration to the plumbing. My coach has
the
> > gray plastic pipe (polybutyl -- that's no longer used as it was
the
> > subject of class-action lawsuits in the late 90s due to unexpected
> > failures in homes and manufactured homes). I purchased "Flare-It"
> > fittings from PEX Connection along with a few feet of 3/4 inch
I.D.
> > PEX tubing. PEX can be bent around corners so long as it has a
> > suitable bending circumference (which is a chore to accomplish in
the
> > space available for the pump). So, from the end of the original
> > plumbing, I have a 3' section of PEX looped to turn 90 degrees to
> > enter the pump, which is mounted on one of the (apparently) wooden
> > boards attached to a metal bulkhead where one of the original dual
> > pumps was located. Again, on the outside, I have another similar
3'
> > section of PEX with a large loop to connect to the outbound
original
> > plumbing. This effectively isolates the pump from transmitting
> > vibrations through the plumbing system. The PEX tubing is
(somewhat)
> > flexible and the dual curves allow
vibration/expansion/contraction as
> > necessary.
> >
> > The higher pressure did not cause any unexpected problems with the
> > existing plumbing -- except the main fresh water drain valve
started
> > leaking from a long-existing crack in the plastic valve body. (I
> > could see that it had been present for some time due to the dirt/
> > corrosion present.) I then replaced the drain valve and associated
> > fittings with brass or white plastic as appropriate.
> >
> > The pump doesn't vibrate the plumbing but it isn't
exactly "silent."
> > The mounting, even with rubber 'feet', etc. still vibrates the
> > bulkhead it's attached to, so you can hear the pump when it is
> > running -- but it's not particularly intrusive and you don't hear
it
> > over the "whoosh" of the shower, for example.
> >
> > I note, too, that I started having a problem with the Microphor
> > toilet flushing. It does not "like" water pressure above 50 psi
and
> > doesn't flush properly at the 65 psi from the water pump. I've
> > learned to open a water faucet valve on the bathroom sink, then
flush
> > the toilet in the fraction of a second before the pump kicks on --
> > temporarily solving the Microphor problem until I can install a
> > pressure limiter on the water line that serves the toilet.
> >
> > All-in-all, I'm very satisfied with the 6.7 gpm 65 psi variable
speed
> > pump. It has eliminated the two original pumps (that were both
> > leaking) and the complexity of the related plumbing along with the
> > accumulator (expansion) tank. (Another source of plumbing woes if
the
> > diaphragm leaks or it becomes de-pressurized.)
> >
> > I'm also enthusiastic about PEX tubing (pipe replacement) and the
> > Flare-It fittings. While special clamped fittings are often used
with
> > PEX (requiring a special clamping tool), the Flare-It fittings
don't
> > require any special tools, but a simple wrench-thing they sell
makes
> > tightening them a breeze (I used a channel-lock plier, but their
tool
> > would probably not leave tool marks like the pliers).
> >
> > In retrospect, about the only thing I might have done differently
is
> > to use 1/2 inch I.D. PEX tubing. It would have been much easier to
> > bend into the loop shapes in the area I had available -- still, I
was
> > successful with the 3/4 inch tubing and it does not restrict the
> > water flow.
> >
> > I do not get "pulsating" very often ... but sometimes, when the
> > bathroom or kitchen sink faucet is turned on, I see just a little
bit
> > of it -- but it goes away in a moment after the pump fully comes
up
> > to speed. I've never noticed it with the shower but, perhaps, the
> > flow limiter in the shower head allows the pump to 'catch up'
before
> > any pulsating begins.
> >
> > The water is heated in an AquaHot system -- this is a tankless hot
> > water system, so there shouldn't be any air pockets (as in a hot
> > water heater) on a newer coach. (I assume you have an AquaHot.)
> >
> > Did you install the high-capacity water filter? I note that the
> > variable speed pump requires a high-flow filter. It was about
twice
> > the size as the water filters used with the old pumps in my coach.
> >
> > Rather than an air pocket, there simply may be a restriction
> > somewhere in the lines into or out of the pump, causing it to be
> > unable to fully come up to pressure as fast as it should, when a
> > valve is opened.
> >
> > Pete Masterson
> > '95 Blue Bird Wanderlodge WBDA 42
> > aeonix1@...
> > On the road at Lockhart Texas
> >
> > On May 1, 2007, at 2:50 PM, David Brady wrote:
> >
> > > I also have the Shurflo Smart Sensor 5.7 65psi pump. My inlet
> > > and outlet plumbing are long lengths of 3/4" ID tubing. The
> > > connections to the pump are the Extreme Series Straight
> > > fitting 3/4" quick connects, part number 94-615-04. These
> > > fittings eliminate any elbows at both the inlet and
> > > outlet of the pump. The trouble is, I still get pulsating and
> > > hunting while the pump tries to zero in on the pressure and flow
> > > required. Anyone else have this problem? It's worse on the
> > > hot water than on the cold. I suspect an air pocket somewhere,
> > > probably in my hot water heater. It gets better with time, but
> > > by then, my fresh water tank is close to empty, it's time to
fill
> > > up, and the pulsating starts again. Again, I'm thinking an air
> > > pocket.
> > >
> > > David Brady
> > > '02 LXi, Smokey
> > > NC
> > >
> > > Pete Masterson wrote:
> > >>
> > >> THe original pump in my coach provided 40-45 lbs pressure. I
> > >> installed a ShurFlo variable speed pump that provides 65 lbs
> > >> pressure. The coach plumbing seems to be 'up' for this
although I
> > >> have an anomaly with the Microphor toilet (it doesn't like
pressure
> > >> above 50#). Mostly, the higher pressure gives you a
better "user
> > >> experience" when you take a shower. The variable speed pump
also
> > >> eliminates the need for the accumulator (expansion) tank.
> > >>
> > >> Pete Masterson
> > >> aeonix1@... 40mac.com>
> > >> '95 Blue Bird Wanderlodge WBDA 42'
> > >> El Sobrante, CA
> > >>
> > >> On May 1, 2007, at 11:35 AM, Keith Strehle wrote:
> > >>
> > >>> I am going to replace my water pump this weekend. There are
ShurFlo
> > >>> pumps available on the shelf for about $70. The pump is
supposed to
> > >>> put out 45 psi but I've heard many people here talk about the
65 psi
> > >>> pumps. 65 psi seems a little much. Is 65 psi necessary and
how much
> > >>> does the original pump put out?
> > >>>
> > >>> Thanks, Keith
> > >>> 84FC35
> > >>>
> > >>
> > >>
> > >> ----------------------------------------------------------
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> > >>
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> > >
> > >
> > >
> > > Yahoo! Groups Links
> > >
> > >
> > >
> >
> >
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5/1/2007 2:10 AM
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