Dometic 500Plus Series Troubleshooting Guide, Problem, Possible Cause, Service Instructions

TROUBLESHOOTING GUIDE

Problem		Possible Cause		Service Instructions
13.Vacuum pump is running too	a. Gear motor is worn or defective.		a. Check motor and replace if
slow, overheating, blowing	b. Plugged vent line or vent filter.			necessary.
fuses or circuit breaker.			b. Disassemble and clean out vent
				line. Replace vent filter if
	c.	Blockage in discharge line.		necessary.
			c.	Disassemble and clean discharge
				line. Be certain that in-line valves
				(duckbill valves) and seacock are
	d. Improper wire size.			in proper position.
			d. Wire size too small. Check
				electrical diagram for proper wire
	e. Improper voltage.			size for voltage of pump used.
			e. Check input power for low voltage.
	f.	Vacuum pump bellows clogged	f.	Remove and clean bellows
		with tissue.		assembly. (When flushing toilet,
				using more water may alleviate
				this problem.)
14.Toilet will not flush.	a. There is a blockage in the system.		a. Open flush ball and check the 1-
(No vacuum.)				inch (25mm) orifice at the bottom
See problems 3 and 15				of the base for blockage and
if necessary.				dislodge it. Never use drain-
				opening or other household
				plumbing chemicals.
				If blockage is not in base, it may
				be found in these locations:
				• outlet of vacuum tank
				• inlet of vacuum generator
				• diptube of vacuum generator
	b. Pump will not run.			• inlet of vacuum pump
			b. See problem 12.
	c. Duckbill valves in vacuum pump		c. Replace duckbill valves, making
		are inverted due to blocked		sure they point in the correct
		discharge line or an attempt to		direction.
		pump out against closed seacock.
15.Blockage between toilet and	a. Collapsed vacuum line.		a. Inspect vacuum line for collapsed
vacuum generator.				condition and replace line if
	b. Sharp bends or kinks in vacuum			needed.
			b. Inspect vacuum hose for kinks or
		hose.		bends. If less than 8.5-inches
				(216mm) radius on any bend,
				reposition hose to achieve
	c.	Improper operation of toilet.		minimum 8.5-inch bend radius.
			c.	Make sure each person using
	d. Foreign objects were flushed down			toilet knows correct procedure.
			d. DO NOT flush any non-dissolving
		toilet.		items (i.e. sanitary napkins, facial
				tissue, wet strength tissue, paper
				towels, etc.) or excessive toilet
				tissue down toilet. Rapid-dissolv-
				ing SeaLand brand toilet tissue is
				best.
16.Pump emits odor.	a. Loose or defective hose		a. Tighten connections or replace
		connection on pump.		hose and make new connections.
	b. Loose intake or discharge fittings		b.	Tighten intake or discharge fittings
		on pump.		on pump. Replace nipples or
	c. Worn, torn or punctured pump			adapters if necessary.
			c. Replace pump bellows or
		bellows (vacuum generator) or		diaphragm.
		diaphragm (vacuum holding tank).

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