Water pump (one more time)

[Pete Masterson]

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@...
>> '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
>>>
>>
>>
>> ---------------------------------------------------------------------
>> ---
>>
>> No virus found in this incoming message.
>> Checked by AVG Free Edition.
>> Version: 7.5.467 / Virus Database: 269.6.2/782 - Release Date:
>> 5/1/2007 2:10 AM
>>
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
>
> Yahoo! Groups Links
>
>
>