26
17-08-00
All Models
PRESSURE SWITCH ADJUSTMENT
1.
With pump and heater on, turn adjustment
knob (clockwise) until a click is heard
from the gas valve.
2.
Turn adjustment knob
(counter clockwise)
1/4 turn.
3.
Turn pump off and on several times.
Heater should shut off immediately. If it does
not,repeat steps above until proper
adjustments is made.
Adjustment
Knob
PRESSURE SWITCH ADJUSTMENT RANGE
NOTE:
If heater is installed outside of the limits
shown, a flow switch must be used in place of the
pressure switch when mounted and wired adjacent to
the heater.
TWO SPEED PUMPS
In some cases, the flow on the low speed is insuffi-
cient to operate the heater. This is apparent when the
pressure switch cannot be further adjusted or if the
heater makes banging noises. In these cases, the
pump must be run at high speed when heating the
water.
CAUTION:
Do not operate the heater without the
function of a properly adjusted pressure switch or flow
switch.
1.5 m Max
1.5 m Max
FLAME ROLL-OUT SAFETY SWITCH
The heater is equipped with a thermal cutoff device to
prevent flame roll-out in the event that the heat
exchanger becomes blocked. This is a "Single-use"
type fusible link or thermal fuse, that must be replaced
when disabled by an over temperature condition,
caused by excessive restriction in the heat
exchanger flue passage.
HIGH LIMITS
The heater is equipped with one manual reset over-
heat thermostat located in the return header, set to
open at approx. 100°C. the other is the Automatic
Gas Shut-off limit, set to open at 57°C and located in
the Inlet/Outlet header.
NOTE:
An erratic high limit is often characteristic of
internal heat exchanger problem, i.e. scale buildup,
defective bypass. Refer to troubleshooting sections.
055, 105 & 155 Models
HIGH LIMIT & MANUAL RESET HIGH LIMIT THER-
MOSTAT REMOVAL
Disconnect top portion of unit. (See heat exchanger
removal procedure steps 1 thru 7 and step 10).
1.
Remove Jacket Top,Flue Collector and Baffle.
2.
Remove defective high limit and replace with
new high limit.
Manual Reset
High Limit
Thermostat
Automatic
Gas Shut-off High
Limit Thermostat
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Automatic
Reset
Thermostat
