Ignition Sequence not activated when burner light is on (Fan is on and Fenwal not flashing)Ĭheck for 24 Volts between terminal B1 on Sentry & Ground.ġ. Check venting termination with required venting described in manual. If 24V is not present replace transformer.Ģ. If so check for 24V between C and D terminals, see wiring diagrams. A problem is indicated when ASC is displayed continuously.ġ. It can occur momentarily during normal operation. This is displayed when the boiler has turned the blower off and is expecting the air switch to be open. If fan is not running, check 120V wiring to blower, if ok remove low voltage harness from blower, if blower fails to start, replace blower, if blower does start problem may be with blower or Sentry control.ĪSC Indicates that the Air Switch is Closed The GX-400 condensate drain switch must be set at 3 in, 76 mm WC.Ĥ. If fan is running, air switch may be faulty, ensure that it’s set for 0.2 in, 5.1 mm WC. Check for blockage on the intake and exhaust vents.ģ. Negative side of switch connects to the port on the 1 1/2 in, 38 mm, ABS elbow.Ģ. Are the vinyl tubes connected between the air switch and the ports on the inlet pipe. A problem is indicated when ASO is displayed continuously.ġ. This is displayed when the boiler is expecting the air switch to be closed by a differential pressure generated when the combustion blower turns on. If DHW temp light is turning off the aquastat or call for domestic has been satisfied.ĪSO Indicates that the Air Switch is Open If the thermostat demand light is turning off, the thermostat has satisfied.Ģ. If OD probe is being used, the HI setting will be calculated using formula in Section 8.ġ. Reset calculation being used to lower HI setting. Check for proper water flow and flow switch operation.īurner shuts off before set-point temperature is reached (and burner light goes out) the Flow Switch on the GX-400 is also in the 24V circuit. Check for 24V between B on terminal block and F1 on Sentry plug, if not present a limit has tripped (see wiring diagram).ģ.
(Sentry will retry ignition sequenceġ hour after ER6 code originally occurs or if control is reset)Ģ. Check ignition sequence to determine which component is not functioning. There is a problem in the ignition sequence it could be caused by a faulty igniter, flame sensor, gas valve or improper line pressure or combustion. “Flame Lock Out” Sentry has sensed a lack of 24V to the gas valve during operation or a Fenwal ignition lockout.ġ. Reduce indirect Aquastat setting, or Increase difference between (Lo Setting) and (indirect Aquastat setting). 0.4 Us, flow is going through boiler & indirect circuit.Ģ. Not enough flow to keep boiler from tripping on limit. The Indirect call will now be ignored until power is reset or the indirect call is interrupted.ġ. The control has determined an Indirect water heater problem the boiler has cycled off 10 times during a single call for domestic. (Note: ER3 will be displayed if temperature sensed is less then 32☏, 0☌.) Note: If problem is corrected by resetting power, Sentry control had locked-up contact Hydrotherm. Or, the wiring to the outdoor probe is grounded.Ĭheck wiring. Water probe.Sentry is sensing an open circuit at water probe. The water probe is transmitting an invalid signal - closed circuit. Reduce the Hi setting (and/or) ensure that there is proper water circulation in the system. Check to see if water is dripping on the sensor.Ģ. The Safety High Limit of 215☏, 102☌, has been reached.ġ.
HydroTherm GX SERIES boilers troubleshooting Refer to vent damper manufacturer's instructions.
Check National Fuel Gas Code and vent manufacturer's recommendations.Ĩ. Undersized chimney or vent, high draft loss in vent.ĥ. Clean flueways or vent and remove obstructions.ĥ. Shut down boiler and notify gas provider.Ĥ. Incorrect thermostat heat anticipator setting.Ģ.
Shut down and cool boiler, drain and flush system.Ħ. Check circulator, replace if necessary.ĥ. Check chimney and venting recommendations.Ĥ. Increase rate to input on rating label.Ĥ. Check air supply, ventilation and venting system.ġ. Check air supply, ventilation and venting system.ĥ. Excessive downdraft or draft problems in boiler room.Ħ. Improperly sized/drilled orifice spuds.ĥ. Troubleshoot intermittent ignition gas valve. Check and correct in accordance with wiring diagrams.ġ0. Start boiler using Lighting/Operating Instructions.Ĩ.
Check wiring and contacts, relay, temperature setting. HydroTherm 70-195 boilers troubleshootingĢ.