Dometic 500Plus Series - Manual (Page 11)

11
TROUBLESHOOTING GUIDE
6. Lifting foot pedal does not
add water to the bowl.
7. Water leaking from water
valve.
8. Water leaking from rear of
toilet bowl.
9. Water is leaking from the
base/toilet connection.
10.Vacuum pump running too
often between flushes.
(See Vacuum Tester
Information on page 9.)
11.Vacuum pump will not
shut off.
12.Vacuum pump will not run.
a. Too much clearance between the
cam strap and water valve.
a. Water valve body cracked due to
freeze damage.
b. Water line connection is loose or not
seated properly.
c. Defective water valve.
d. Stripped threads.
a. Worn or defective vacuum breaker.
b. Loose vacuum breaker.
c. Cracked or defective toilet bowl.
a. Clamp ring may be loose.
b. Ball seals may be worn or defective.
a. Water leaks out of bowl between
flush ball and ball seal.
b. Vacuum line leak.
a. A vacuum leak exists.
b. Insufficient vacuum (pump creates
less than 10 inches Hg).
c. Faulty vacuum switch (pump creates
more than 10 inches Hg).
d. Improper wiring.
e. Bellows not pumping.
a. No electrical power.
b. Loose or broken electrical wiring.
c. Improper electrical connections.
d. Faulty vacuum switch.
e. Faulty motor.
f. Shut-down relay prevents pumping.
a. Adjust cam strap so clearance is
.06 inches (1.5mm) maximum.
a. Replace water valve.
b. Insure that threads are not cross-
threaded and tighten.
c. Replace water valve.
d. Replace water valve.
a. Remove white cap from vacuum
breaker. Flush toilet. If water leaks
during flush, vacuum breaker
needs to be replaced.
b. Secure vacuum breaker
connection.
c. Replace toilet bowl.
a. Remove plastic base cover (on
applicable models) and tighten the
clamp ring.
b. Replace ball seals.
a. Leave small amount of water in
bowl. If water is sucked from bowl,
see problems 1 and 2.
b. Tighten all connections at toilet,
vacuum generator or vacuum
holding tank (including hose
clamps and threaded spin nuts). If
leaks persists, contact SeaLand
Product Customer Service.
a. See problem 9b.
b. Isolate pump and use vacuum
gauge to check vacuum levels.
Could be a plugged discharge line
or worn duckbill valves.
c. Replace vacuum switch.
d. Refer to wiring diagram to check
for proper wiring.
e. Tighten set screw in eccentric to
motor shaft. Otherwise, check for
damage to bellows and motor
shaft. Replace if necessary.
a. Check input power, circuit breaker
and fuse.
b. Tighten or reconnect wires at
vacuum pump and tank, vacuum
generator, or vacuum holding tank.
c. Make certain wires at vacuum
switch are connected to the “B”
terminals.
d. To check vacuum switch, short
across “B” terminals with jumper
wire.
e. Replace motor.
f. Empty the holding tank.
Problem Possible Cause Service Instructions