Troubleshooting Step By Step Procedure
The following is a step by step procedure to help in troubleshooting any problems with this
boiler. These steps should be performed only by qualified personnel with experience in
hydronic heating systems, and electrical heating equipment. You are working with high
voltages and should be extremely careful.
Before energizing boiler, ensure system is full of water.
(1) Make sure that there is power to the boiler. There must be power to the boiler to
complete these troubleshooting steps.
a) On 240 volt single phase models there should be power at the main terminal block.
You should read 120 volts between L1 and N, 120 volts between L2 and N, and 240
volts between L1 and L2.
b) On three phase models there should be power at the main terminal block. You should
take three readings on the main terminal block, you should read the appropriate
voltage for your model between L1 and L2, between L2 and L3, and between L1 and
L3. You should also read 120 volts on the terminal block on the lower right side on
the terminals labeled SL and SN.
c) Disconnect the thermostat wires from the terminals “STAT 1”. Measure the voltage at
the top of the boiler at each heating element. If you measure voltage at any of the
elements, then the element relay for that element is stuck on and needs to be
replaced.
(2) Check the fuse on models equipped with a fuse.
a) Remove the fuse located inside the boiler. Check it for continuity. Replace with a new
fuse of the correct type if necessary.
b) Otherwise replace the existing fuse.
(3) Check that there is 24 volt AC power on the secondary side of the transformer. These
are the two wires running from the transformer to the control board. There must be 24
volt AC power on the secondary side of the transformer for the boiler to operate. If there
is no power the transformer needs to be replaced.
(4) With the thermostat wires still disconnected from step (1)c), disconnect the outdoor
sensor as well, then connect a jumper wire from one terminal of STAT 1 to the other
terminal of STAT 1.
a) This should energize the relay to the right of the control board, you should hear a
click. If not check that there is 24 volt AC power on the two terminals with purple
wires.
b) If there is no power at the relay, the control board needs to be replaced.
c) If there is power, but the relay is not turning on, replace the relay.
(5) When the relay is energized, it will supply 120 volt power for running the pump, and
activate the control board.
a) There should now be 120 volt AC power to the terminals labeled PL and PN.
b) If there is no power, replace the relay.
(6) With the circuit board now activated, the power relays should turn on one at a time.
There is about a one to two minute delay before the first relay turns on, and about the
same for each additional relay. If they have not started to come on as yet, temporarily
20
