tekmar 360 Mixing Control - Manual (Page 18)

© 2009 D 360 - 03/09 18 of 20
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 diagnosing
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 inter-
mittent? 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, however, 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 assistance 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 infor-
mation 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 correct times?
Is the control receiving the correct signals from the system as to when it should be operating? 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.
Establish the
Problem
Understand the
Sequence of
Operation
Use the Test
Routine
Sketch the
Piping in the
System
Document the
Control
Isolate the
Problem
Test the Contacts,
Voltages &
Sensors
Troubleshooting