Mandalay 38A 2004, Owner'S Manual

Page: 66 / 94

Common Field Problems
1. Inaccurate holding tank level readings
2. Some or all holding tank level lights not coming on
3.
Some or all holding tank level lights continuously on
4. LP gas levels not reading properly
Inaccurate Holding Tank Level Readings
The accuracy of two wire holding tank monitoring systems can be adversely affected by dirty tanks, unusual
mineral content in the water, or improper holding tank probe location. These conditions can cause the
monitoring system to have oversensitive (read higher than actual level) or under sensitive (read lower than
actual level) readings.
Oversensitive readings:
Oversensitive readings can occur as a result of scum buildup on the tank walls,
abnormally high mineral content in the water, or incorrectly located holding tank probes. In these situations,
the monitoring system indicates higher levels than are actually present in the holding tank. Certain cleaning
products and food by-products can build up on the inside walls of the holding tanks, producing a layer of scum
that can cause the monitoring system to read higher than the actual level. To correct this problem, the holding
tanks should be cleaned periodically (consult dealer for cleaning instructions). If the problem persists after
cleaning the holding tank, the ground probe can be moved farther away from the other tank probes. The
increased distance between the ground probe and the other probes will decrease the sensitivity of the
monitoring systems.
Under sensitive readings:
Under sensitive readings can occur if the mineral content of the water is
abnormally low or if the holding tank probes are located incorrectly. In this case, the monitoring system
indicates lower levels than are actually present in the holding tank. This problem can be corrected by moving
the ground probe closer to the other probes. Moving the ground probe closer increases the sensitivity of the
monitoring system.
The Ventline Adjustaboard
™
:
In response to requests from the field for a means to adjust monitor sensitivity
without relocating holding tank probes, Ventline has developed the Ventline Adjustaboard™ (patent pending).
This adjustable circuit board allows for field adjustments to monitor sensitivity. As tank conditions or water
mineral content changes, the monitor circuitry may be made more or less sensitive as required.
WASTE WATER SYSTEM
The waste water system in your RV can be described as two separate systems. A gray water system that
consist of the drain lines and holding tank for waste water from the sink and tub, and a black water system
which includes the holding tank and drain for toilet waste. In some cases the bathroom lavatory may drain into
the black tank. Each system is self contained, and allows disposal of waste at designated dump stations at
your convenience.
Components of the gray water system have drain traps, and both tanks are vented to equalize air pressure and
disperse odors caused by drain water and wastes outside. Sometimes, the rocking movement of the RV while
driving may empty the drain traps of their water, and allow the odors of the gray water tank to come into the
coach. Residue in the drain water lines can also produce odors. To combat gray water holding tank odors, an
approved deodorizing agent should be used. An agent that dissolves grease and fats and contains a detergent
will help keep tank drain lines clean and free-flowing.
9-4 Mandalay