Install Instructions

CG i GAS-FIRED wATER BOILER- sERIEs a- Boiler Manual
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Troubleshooting - control module lights (cont.J
CHART 2- TSTAT CIRC & POWER lights flas hm g
- Usually indicates 48 VAC on thermostat circuit (stray voltage) -
I& WARNING I
Electrical shock hazard - Wherever you see .t. TURN OFF POWER& , follow the instruction s. Failure to follow
instructions could result in severe
personal injury, death, or substantial property damage.
.
Disconnect the two external wires connected to the bo iler
.
If a voltage does occur under any condition, check and
thermost
at leads (two black l ow voltage leads in J- box). correct the external wir ing. (This is a common probl em
Connect a vo ltmeter across these two incoming wires .
when using 3-wire zone valves.)
.
Close each thermostat, zone valve and relay in t he external
.
Once the external thermostat c ir cu it wiring is checked and
c
ir cuit one at a time and check the voltmeter reading correct ed if necessary, reconnect the external thermostat
across the wires. circuit wires to the
bo iler thermost at wires and allow the
There should NEVER
be a voltage reading .
bo iler to cycl e.
.
Did you find a voffage across the 1\Vo external thermostat circuit wires?
Yes
No
.
Leave external bo iler thermost at connection wires
.
If no vonage is found under any condition of t he external
disconnected from
bo il er.
th ermostat c ir cuit, connect the two boiler thermost at
connect io n leads toget he r (o r jumper t he bo iler aquastat
.
Troubleshoot the external thermostat c ir cu it until you find
T-T terminals) .
the source
of the st ray voltage. ( Pa y close attent io n to
the wiring connect
io ns to 3-wire zone valves.)
~
.
T um off power to the boiler f or 1 minute.
.
Co rr ect the pr ob l em and repeat the voltmet er test above,
T
um on power and allow bo iler to cycle .
.
verifying t he re is no lo nger a vo ltage reading under any
condition in the external thermost at circuit.
Do the TSTAT and POWER lights sli//tiash?
.
An isolating relay may be required .
- No
I I
Yes
.
Boiler should now operate pe r t he normal sequence of
I:
Repla ce control module .
operat
io n shown in Figure 30, page 38.
Retes
t.
Part Num ber 550-142-780/0712 55