Shutting down the heater

1. While the heater is in low fire set the switch marked HEATER CONTROL to OFF (Fig. 2).

2. Allow the circulation pump and the auxiliary pumps (HC heater only) to continue operating for approximately 10 minutes.

3. Set the switch marked CIRC. PUMP to OFF (Fig. 2).

4. For HC heaters, set all switches marked AUX. PUMP to OFF.

5. Make sure these valves are closed:

   • Main gas manual shutoff valve ( Fig. 7).
   • Secondary gas manual shutoff valve (Fig. 7).
   • Pilot gas manual shutoff valve (Fig. 7).
   • Close valve in the fuel oil supply line to heater.

6. Set the power disconnect switch (the handle) on the control panel (Fig. 2) to OFF.

Starting heater for routine operation
Follow steps 1 through 9 of the procedure for purging water from the system.

Flame scanner precaution
The flame scanner and amplifier used on HC and HCS heaters are the non-self checking types . However, the flame monitor checks the flame scanner each time the heater is started. Consequently, it is extremely important that the heater cycles off and on a minimum of once every 12 hours.

If the heating system is highly stable (as it should be), the heater may not automatically cycle off and on that often. Therefore, to ensure that the flame scanner is okay, you should manually switch the heater off for a second or two and then back on. Do this once each morning and once again late in the day.

In the event that the flame scanner fails while the heater is operating, it may not shut the heater down. Thus, the scanner could allow the fuel valves to remain open, even if there is an inadvertent loss of flame. This would allow the heater and surrounding area to become saturated with unlit fuel, creating an extremely unsafe condition.

If you try to restart a heater that has a defective flame scanner, the heater will not restart. Instead, the flame monitor will show the message FALSE FLAME. This most likely indicates that the flame scanner is bad and should be replaced. Although a defective amplifier, programmer or chassis can also cause a false flame indication, a defective flame scanner is usually the problem.

Never disconnect and reconnect the flame scanner or take any other action to circumvent the scanner in order to restart the heater. Instead, replace the component. Otherwise, you could create an unsafe condition as described above.