General Troubleshooting
ETS Module
©Aqua-Hot®
125-DN1 Service Manual
REV 220421
©Aqua-Hot®
125-DN1 Service Manual
REV 220421
p. 41
p. 40
The first operation of the burner with the Aqua-Hot after service
may not light up perfectly. This is normal and may take a couple
tries to get the fuel lines purged of air before a successful start-
up.
Activation Instructions (Diesel Burner)
1. Make sure there are no blockages or debris to the exhaust
outlet or combustion air inlet.
2. Make sure the plumbing lines and fuel lines are properly
purged and free of air.
3. Make sure there is adequate fuel in the vehicle fuel tank
(at the least ¼ tank).
4. Turn on the burner on the heater control switch.
5. Once the burner turns on, the circulation pump and
combustion air fan should run (can be determined by
listening).
6. The burner should start up after approximately 120
seconds. This can be determined by the hot exhaust exiting
from the exhaust tube.
7. Allow the burner to run a full cycle. Turn on the heat or
hot water inside the RV to confirm the burner is properly
operating.
Once these checks have been confirmed, the diesel
burner is now ready for normal operation and use.
NOTE:
Both the electric heating element and the external
diesel burner are thermostatically controlled. The element
and/or burner will automatically maintain the temperature
of the boiler tank’s antifreeze and water heating solution.
Figure 83
NOTE:
It is recommended to run the burner for at least 20
minutes every month to ensure optimum heater condition.
NOTE:
Make sure to perform the fuel line purge procedure
on Page 39 prior to starting this start up of the burner.
Burner First Operation
Failure to follow instructions on the fuel delivery system can
cause damage to the Aqua-Hot 125DN, the diesel burner, or
the RV. It may cause serious personal injury. Please follow
instructions carefully.
Lack of Interior Heat or Hot Water
Introduction:
A lack of interior heat or hot water when provided with
adequate heat from either the electric element and/or the
diesel burner can be attributed to an overheat thermostat, the
Aqua-Hot controller, the three-way valve, or the fluid circulation
pump.
The troubleshooting procedures listed below are arranged in
order of repair complexity. Do not replace parts without correctly
determining the failure.
Follow the directions below in order to troubleshoot the
Aqua-Hot. Do not skip through the troubleshooting steps, as this
may needlessly complicate unit diagnosis and repair.
Troubleshooting Procedure:
• Ensure that the Aqua-Hot is supplied with electrical power.
• Ensure there is an adequate supply of diesel fuel (at least
¼ tank).
• Ensure that the Aqua-Hot boiler tank has an adequate
supply of antifreeze and water heating solution by checking
the level at the expansion bottle. If the level is low,
reference the maintenance section of this guide for refilling
instructions.
• Verify the functionality of any in-line fuses connected to the
Aqua-Hot. Replace these fuses if necessary.
• Ensure that all coach-side hot water faucets are closed.
• Visually inspect the interior of the Aqua-Hot to ensure that
there are not pinched or damaged wires.
• Locate the high-limit thermostats (3) within the Aqua-Hot.
Test these thermostats for functionality, and replace them
if necessary. Reference page 22.
• Locate and test the ETS module for functionality. Replace if
necessary. Reference page 34.
•
Locate and test the fluid circulation pump. If necessary
replace it. Reference page 29.
• Locate the three-way valve and test it for functionality.
Replace if necessary. Reference page 25.
• Make sure there are no faults displayed on the LCD screen.
Reference Figure 86.
NOTE:
The fluid level sensor is located in the Aqua-Hot’s
expansion tank. If the antifreeze solution in the expansion
tank drops below the level of the fluid sensor, the Aqua-Hot
will not operate.
Hot Fluid Line
Cold Fluid Line
Fluid Level Sensor
Fill Cap
Lower Fitting
Expansion Bottle
Connection
Upper Fitting
Figure 85
Figure 84
Figure 86
Low Port Drain
