Page 30 | GT INSTALLATION AND OPERATION INSTRUCTIONS |
The gas supply pressure to the boiler while running at maximum rate must be between 4 to 9 in, 102 to 229 mm, W.C. for natural gas installations; 9 to 12 in, 229 to 305 mm, W.C. for propane installations. This pressure can be measured on the gas valve using a manometer, Figure 41 or 42. Ensure that the regulator is capable of maintaining this pressure under all operating conditions. The gas valve is also equipped with a manifold pressure port, Figure 41 or 42.
Figure 41 - Gas Valve Layout, GT-150 & 200
Figure 42 - Gas Valve Layout, GT-400
Manifold Pressure
Line Pressure
Input Screw 
Ignition System
A.Connect a manometer to the line pressure port shown in Figure 41 or 42. Make sure that the gas supply piping has been purged of air and that all gas joints up to the gas valve have been thoroughly checked for leaks. Wait at least five minutes for any gas to dissipate before turning on the electrical power.
B.Read, understand and follow the operating instructions below.
C.Raise the thermostat at least 5 degrees above the room temperature. The boiler should enter the pre- purge mode before energizing the silicon carbide igniter. Once the igniter is hot, the main gas valve will open and the burner should light. If the burner fails to light the system will make three more ignition attempts. If the burner has not lit after the last ignition try, the gas valve will close and the system will go into lock out. DO NOT attempt to reset the system until the ignition system has been inspected and the problem resolved. Once the problem has been resolved and 5 minutes have passed since the last ignition attempt, reset the system by turning the thermostat to it’s lowest setting and then back to where it was or by momentarily interrupting the electrical power to the boiler.
D.With the burner in operation close the manual shutoff valve in the gas supply line. As soon as the burner fl ame goes out, open the manual shutoff valve. A normal ignition sequence should take place.
E.With the burner in operation, interrupt the power to the control circuit by lowering and raising the thermostat. A normal ignition sequence should follow.
F.To test the ignition safety shutoff device, close the manual shutoff valve in the gas supply line. Within 6 seconds of main burner fl ame extinction, the main gas valve solenoid should close with an audible noise. The igniter should glow and make three attempts at ignition. After unsuccessfully attempting to light the burner the ignition module should lock out.
