Product Manual

TECHNICAL BULLETIN

12V DIAPHRAGM RV PUMPS

Fine Tuning Your Fresh Water Pump

Internal Bypass Operation

In most instances, an RV/Fresh Water Pump will need to

be tuned at install. If you install your pump and you ﬁnd

that it keeps running, do not panic. Just like tuning your

TV channels, your pump needs to be tuned to your system.

To ﬁne tune your pump, the bypass pressure needs to

be adjusted. Voltage and plumbing variations affect the

setting, and the pump needs to be “tuned” to its installation.

Meaning each setup might treat the pump differently – this

is the same for any other RV pump.

The 3055R (11 LPM) and 5055R (18 LPM) pumps are equipped

with an internal bypass feature. By allowing some ﬂuid to

circulate inside the pump, the pumps can operate at low

output ﬂow without on/off cycling caused by pressure switch

activation.

The bypass pressure is calibrated and set at the factory during

assembly. However, voltage and plumbing differences in

individual installations may require an adjustment. If the

pump will not turn off when all plumbing ﬁxtures are closed,

locate the internal bypass adjustment screw on the front of the

pump and rotate clockwise until the pump shuts off. (A 2mm

hex key is required.)

PAGE 1
TECHNICAL BULLETIN 12V DIAPHRAGM RV PUMPS Fine Tuning Your Fresh Water Pump In most instances, an RV/Fresh Water Pump will need to be tuned at install. If you install your pump and you find that it keeps running, do not panic. Just like tuning your TV channels, your pump needs to be tuned to your system. To fine tune your pump, the bypass pressure needs to be adjusted. Voltage and plumbing variations affect the setting, and the pump needs to be “tuned” to its installation.
PAGE 2
Steps for setting the cut-out & internal bypass pressure on 11.4 lpm and 18 lpm RV pumps. 1. Connect the plumbing ports to a water tank. 2. A ball valve and pressure gauge are required in the outlet plumbing line. 3. Turn pump on. 4. To set the internal bypass pressure at 60psi: • • • Slowly close outlet ball valve until completely shut. If pump turns off, rotate cut-out pressure adjustment screw clockwise until pump is running continuously.