Bradford-White Corp BMT2V, BMT2H warranty Operating Temperature Control, External Boiler Operations

Brute Deluxe (500-2000) Page 27

pump, boiler, and radiation units for one (1) hour.

10.Recheck the water level in the expansion tank. If the water level exceeds ¼ of the volume of the expansion tank, open the tank drain, and drain to that level.

11.Shut down the entire system and vent all radiation units and high points in the system piping, as described in Step 4.

12.Close make-up water valve and check strainer in pressure reducing valve for sediment or debris from the make-up water line. Reopen make-up water valve.

13.Check gauge for correct water pressure and also check water level in the system. If the height indicated above the boiler insures that water is at the highest point in the circulating loop, then the system is ready for operation.

14.Refer to local codes and the make-up water valve manufacturer’s instructions as to whether the make- up water valve should be left open or closed.

15.After placing the unit in operation, the ignition system safety shutoff device must be tested. First, shut off the manual gas valve, and call the unit for heat. After the pre-purge and ignitor heat-up time, the main gas terminals will be energized, attempting to light, for four (4) seconds, and then will de- energize. The unit will go into lockout mode. Second, turn the power off and then on again, open the manual gas valve and allow the unit to light. While the unit is operating, close the manual gas valve and ensure that power to the main gas valve has been cut.

16.Within three (3) days of start-up, recheck all air bleeders and the expansion tank as described in Steps 4 and 8 above.

Important: The installer is responsible for identifying to the owner/operator the location of all emergency shutoff devices.

WARNING

Do not use this appliance if any part has been under water. Immediately call a qualified service technician to inspect the appliance

and to replace any part of the control system and any gas control that may have been

under water.

6.3 Operating Temperature Control

All Brute Deluxe's are equipped with a two-stage aquastat. To utilize this mounted controller be sure to have the "Local/Remote" selector switch to "Local". Set the controller to the desired operating set point. The controller has an interstage differential that can be adjusted from 3°F to 10°F. This allows the user to have some control over how stage 2 and stage 1 call for heat (see Figure 22).

Because the Brute Deluxe controller senses inlet water and the manual reset high limit senses outlet water, the high limit should be set 40-50°F higher than the controller, to avoid nuisance lockout of the manual reset high limit.

6.4 External Boiler Operations

If controlling the stages of the BMT2 from an external source (multiple boiler control, BAS, etc) the "Local/Remote" selector switch above the terminal strip must be placed in the "Remote" position. In this mode, the controller that is mounted on the BMT2 will no longer have control of the unit. The 24V from the unit waits at the input terminal, and the external control switches this 24V from the input terminal to the stage terminal.

6.5 Limit Controls

The manual reset high limit control is provided as standard equipment on all heaters. An additional automatic reset switch is optional.A high limit temperature-sensing bulb is always located in the heater outlet. Burners will automatically shut down whenever overheating occurs.

6.6Operating the Burner and Set Up

6.6.1 Set Up for 0 to 2500 Feet Altitude

The Brute Deluxe appliance utilizes a modular

*1 Difference between the temperatures at which the two switches make R-W. Adjustable from 3°F to 10°F (1.7°C to 5.6°C) on standard models, or from 3.6°F to 12°F (2.0°C to 6.7°C); 55°F to 175°F (13°C to 79°C) models.

*2 Two DPDT switches operate in sequence. Each switch differential is fixed at approximately 3°F (1.7°C) on standard models, or 3.6°F (2.0°C); 55°F to 175°F (13°C to 79°C) models.

Figure 22. Honeywell L8008G.