© 2003 D 360e - 06/03 18 of 20
Troubleshooting
Establish the
Problem
Understanding
the Sequence of
Operation
Use the Test
Routine
Sketch the
Piping in the
System
Document the
Control
Isolate the
Problem
Test the Con-
tacts, Voltages
and Sensors
When troubleshooting any heating system, it is always a good idea to establish a set routine to follow. By following a consistent
routine, many hours of potential headaches can be avoided. Below is an example of a sequence that can be used when diag-
nosing or troubleshooting problems in a hydronic heating system.
Establish the problem. Get as much information from the customer as possible about the problem.
Is there too much heat, not enough heat, or no heat? Is the problem only in one particular zone
or area of the building, or does the problem affect the entire system? Is this a consistent problem
or only intermittent? How long has the problem existed for? This information is critical in correctly
diagnosing the problem.
Understand the sequence of operation of the system. If a particular zone is not receiving enough
heat, which pumps or valves in the system must operate in order to deliver heat to the affected
zone? If the zone is receiving too much heat, which pumps, valves, or check valves must operate in
order to stop the delivery of heat?
Press the Test button on the control and follow the control through the test sequence as described
in the Testing section. Pause the control as necessary to ensure that the correct device is operating
as it should.
Sketch the piping of the system. This is a relatively simple step that tends to be overlooked, how-
ever, it can often save hours of time in troubleshooting a system. Note flow directions in the system
paying close attention to the location of pumps, check valves, pressure bypass valves, and mixing
valves. Ensure correct flow direction on all pumps. This is also a very useful step if additional assis-
tance is required.
Document the control for future reference. Before making any adjustments to the control, note down
all of the items that the control is currently displaying. This includes items such as error messages,
current temperatures and settings, and which devices should be operating as indicated by the LCD.
This information is an essential step if additional assistance is required to diagnose the problem.
Isolate the problem between the control and the system. Now that the sequence of operation is
known and the system is sketched, is the control operating the proper pumps and valves at the cor-
rect times? Is the control receiving the correct signals from the system as to when it should be oper-
ating? Are the proper items selected in the menus of the control for the device that is to be operated?
Test the contacts, voltages and sensors. Using a multimeter, ensure that the control is receiving ade-
quate voltage to the power terminals and the demand terminals as noted in the technical data. Use
the multimeter to determine if the internal contacts on the control are opening and closing correctly.
Follow the instructions in the Testing the Wiring section to simulate closed contacts on the terminal
blocks as required. Test the sensors and their wiring as described in the sensor Data Brochures.
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