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P/N 42-9452 8/08 Copyright Hydrotherm
KN USER’S CONTROL MANUAL
Troubleshooting
(continued)
5
Situtation
Suggested procedure
HeatNet boilers are detected but
then lost and then detected again.
Th e H-Net communications cable may be receiving interference from the blower, ignition, or other form
of radiated electrical noise.
Termination of the jumpers may not be correct or there is more than one master.
Ensure that the termination dip switchs are set on the MASTER boiler and only the LAST MEMBER
boiler. All of the other member boilers should have their termination dip switches OFF.
Th ere may be two or more MASTER boilers. Ensure that only one header sensor is present and con-
nected to the HEADER input. Th ere should be no wires or sensors connected to the HEADER input if
the boiler is operating as a member.
Verify that the HNet cables are of a shielded or twisted pair type. Shielding of the cable is required.
Minimize possible electrical interference by routing the communications cables away from electrical
noise sources, such as motors, ignition controls, contactors, etc.
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1.
2.
3.
4.
Only the MASTER boiler Fires, but
the system has many boilers and
is using HeatNet.
In order for the MASTER boiler to act as a MASTER, the header sensor must be set to TYPEZ, and there
must be a header sensor present.
At power-up, the header sensor is auto detected. If the temperature of the header sensor at power-up is
greater than –25 °F and less than 240 °F it is considered a valid sensor. Th
e boiler will default to the MEMBER
mode if the temperature is not in this range, and can only be run locally or by external inputs.
Th e HNet needs a communications cable daisy-chained between boilers. Ensure that a good connection
is made on the communications board and that the lights on the dual RJ45 jacks fl ash (roughly twice a
second). Th e MASTER is the only one that should fl ash with no communications cables plugged in.
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You get the error message –
WATER FLOW SWITCH or WAITING
FOR FLOW.
If the control does not sense a closed circuit at input connection, FLOW SWITCH, check to make sure the
circuit for the circulator pump is correct, that the pump is being energized, and that the fl ow prove switch
is working properly.
If there is no fl ow prove switch, check to make sure that a jumper wire has been connected across the
FLOW SWITCH terminals.
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You have forgotten the password.
Turn the ON/OFF switch off . Th en depress and hold the ESC key while turning it back on. Th is will load
the default password “AAAAAA”.
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Firmware update program starts
to load, but then stops.
Ensure that the USB driver for your PC/Laptop computer is properly installed.
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IN UNITED STATES: 260 NORTH ELM ST. • WESTFIELD, MA 01085 • (413) 564-5515 • FAX (413) 568-9613
IN CANADA: 7555 TRANMERE DRIVE • MISSISSAUGA, ONT. L5S 1L4 • (905) 672-2991 • FAX (905) 672-2883
www.hydrothermkn.com
