Winterizing; Troubleshooting Guide - Dometic SeaLand VHT12 Owner's Manual

WINTeRIzING

At the end of each boating season, the VacuFlush system
must be winterized for storage. The following procedure
should be used:
1. Thoroughly flush system with fresh water.
2. Pump out holding tank.
3. Shut off water supply to toilet, remove waterline.
4. Press flush lever until all water is drained from toilet.
5. Turn off electrical power.
To use antifreeze, repeat Steps  and 2 above and
continue as follows:
CAuTION: The use of freshwater antifreeze that
contains alcohol will result in damage to your sanitation
system. Only use propylene glycol freshwater antifreeze
that does not contain alcohol.

TROuBLeSHOOTING GuIDe

problem
. Pump running too much
between flushes.
2. Toilet will not flush.
(No vacuum.)
3. Pump will not run.
4. Pump will not shut off.
5. Pump is making a
loud noise.
NOTE: If sound of pump is
disruptive at night, an "On-Off"
switch may be easily added to the
system. The VacuFlush Status
Panel features an integral circuit
breaker which also serves as a
night switch. (#50002, 2 VDC;
#500024, 24 VDC)
possible Cause
a. Flush ball in toilet leaks.
b. Vacuum line leak.
c. Foreign material has fouled
air pump valves.
d. Pump diaphragm worn or
damaged.
e. Duckbill valve in discharge
fitting stuck open.
a. Pump will not run.
b. Plugged vacuum line.
c. Plugged pump valve.
d. Vacuum pump discharge or
intake lines plugged.
a. No power.
b. Loose or broken electrical
wiring.
c. Improper electrical
connections.
d. Faulty vacuum switch.
e. Faulty motor.
a. Insufficient vacuum.
b. Excessive vacuum leak.
c. Faulty vacuum switch.
d. Improper wiring.
a. Loose set screw in crank
assembly.
b. Pump bearing is worn.
c. Dirt or debris in pump body.
d. Worn or defective motor.
e. Motor loose from mounting
bracket.
6. Drain potable water tank.
7. Add freshwater antifreeze to potable water tank.
8. Flush potable water antifreeze and water mixture
through toilet and into the vacuum holding tank. Each
installation is different so amounts may vary. User
discretion is required to assure adequate protection.
9. Pump out vacuum holding tank.
0. Turn off electrical power.
Service Instructions
a. Leave small amount of water in toilet. If water is
sucked from bowl, refer to "Troubleshooting
Guide" in VacuFlush Owner's Manual.
b. Tighten all hose connections at pump, vacuum tank,
holding tank, and toilet.
c. Disassemble air pump and inspect under the
two flat disk valves. If foreign material is
present, remove debris and reassemble air pump.
d. Inspect diaphragm in pump for small hole or rip.
Replace if necessary.
e. Disassemble discharge outlet and inspect
duckbill valve. Clean or repair if necessary.
a. See problem 3.
b. Blockage usually at base of toilet below flush
valve. You may have to disconnect line and clear.
c. Inspect and clean pump valves. Replace if needed.
d. Disassemble lines and clean.
a. Check input power, circuit breaker and fuse.
b. Tighten or reconnect wires at pump and
vacuum 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.
a. Verify pump pulls minimum 0 inches Hg of vacuum.
b. See problem .
c. To check switch, remove one "B" terminal wire.
d. Check wiring. Refer to Wiring Diagram.
a. Remove cover from pump and check crank
assembly setscrew for tightness.
b. Check pump bearing for wear. Replace if needed.
c. Disassemble air pump assembly and inspect
inside of pump body for foreign objects.
d. Replace motor assembly.
e. Tighten the two (2) nuts securing the motor to
the mounting bracket.
6