Laars Rheos RHCH, Installation And Operation Instructions Manual, Page: 44 / 60

LAARS Heating Systems
Page 44
determined the actuator is working properly, the gas
valve body may need to be replaced. To remove the
gas valve body, shut off 120V power and the gas
shutoff valve. Remove the right side and front panels.
Remove the valve actuator. Unscrew the valve body
from the gas train. After the valve has been removed,
replace with a new valve in reverse order. Turn on gas
shutoff valve and 120V power and check appliance
operation and tightness of gas valve connections.
7.2.15 Gas Pressure Switches
The high and low gas pressure switches are 24V
manual reset switches that act to cut power to the gas
valves if the gas pressure is too low or too high for
proper operation. The gas pressure switches used are
integrally vent limited, and do not require venting to
atmosphere. To remove a switch, remove the screw
on the plastic housing and pull the clear cover off.
Disconnect the two wires from the screw terminals.
Twist the switch off the pipe nipple. Reassemble in
reverse order. For natural gas, set the low gas pressure
switch to 3" w.c. For propane, set the low gas pressure
switch to 5" w.c. For natural and propane, set the high
gas pressure switch to 14".
Figure 38. Control Panel.
Figure 37. Gas Train.
Solenoid Safety
Gas Valve
Modulating Gas
Valve Actuator
Modulating Gas
Valve Bodies
Manual
Gas Valve
On/Off Gas
Valve Actuator
Gas Orifice
Low Gas
Pressure Switch
Pressure
Differential
Tube Assembly
Pressure
Switch
Air Inlet
Transition
High Gas
Pressure Switch
Control Packs B and E Gas Trains
High Gas
Pressure Switch
Modulating Gas
Valve Body
Manual
Gas Valve
Solenoid Safety
Gas Valve
Air Inlet
Transition
Pressure
Switch
Gas
Orifice
Pressure
Differential
Tube Assembly
Modulating Gas
Valve Actuator
On/Off Gas
Valve Actuator
Low Gas
Pressure Switch