Bradford-White Corp BMT2H, BMT2V warranty High Altitude Adjustment and Set Up

Page 28 BRADFORD WHITE CORP.

design to achieve its stage-firing. The setup must be checked before the unit is put in operation. Problems such as failure to start, rough ignition, strong exhaust odors, etc. can be due to improper setup. Damage to the Brute Deluxe resulting from improper setup is not covered by the limited warranty.

1.Using this manual, make sure the installation is complete and fully in compliance with the instructions.

2.Determine that the appliance and system are filled with water and all air has been bled from both. Open all valves.

3.Observe all warnings on the Operating Instructions label and turn on gas and electrical power to appliance.

4.Switch on the appliance power switch located on the right side of the unit.

5.The Brute Deluxe will enter the start sequence, as long as the unit is being called for heat. The blower and pump come on for pre-purge, then the ignitor warm-up sequence starts and after the ignitor warm-up is complete and all safety devices are verified, the gas valves open. If ignition doesn’t occur, check that there is proper gas supply. Wait 5 minutes and start the unit again. During initial start up, air in the gas line may cause the Brute Deluxe to "lock out" during the first few trials for ignition. Depending on the ignition modules installed, the manual reset button on the ignition modules may need to be depressed to restart the Brute Deluxe.

6.When the unit is running, the supply gas pressure must be checked. Inlet gas pressure must not exceed 13" W.C. (3.2kPa). The minimum inlet gas pressure is 5" W.C. (1.2kPa).

7.Once the inlet gas pressure is verified, the outlet gas pressure from each valve (manifold gas pressure) must be checked, and adjusted, if necessary. The manifold gas pressure must be 2.5" W.C. (0.62kPa).

8.Complete the setup by checking the CO2 at the outlet of the unit. The CO2 should be 8% for natural gas, or 9.2% for propane.

9.After placing the appliance in operation, the Burner Safety Shutoff Device must be tested.

(a)Close gas shutoff valve with burner operating.

(b)The flame will go out and blower will continue to run for the post purge cycle. One additional attempt to light will follow. Ignition will not occur as the gas is off. The ignition control will lockout, and will have to be reset before the unit will operate.

(c)Open gas shutoff valve. Restart the appliance. The ignition sequence will start again and the burner will start. The appliance will return to its previous mode of operation.

NOTE: Unit sizes 1000–2000 have two ignition controls and two ignitors, which work independently of one another. If the ignition control for stage 1 fails to properly

light the main burners for that stage, the second ignition control will still be active, and will be able to energize stage 2. This, of course, will only occur upon call for stage 2 and if all other safety devices confirm that the unit will run in a safe condition.

6.6.2High Altitude Adjustment and Set Up

Brute Deluxe appliances may be operated at high

altitude (7700 ft., 2347 m) with a reduction in output of approximately 10%. At altitudes of less than or more than 7700 ft. (2347 m) the appliance will perform equally as well, but with differing reductions in output. At elevations higher than 7700 ft. (2347 m) the reduction in output will exceed 10% and at elevations below 7700 ft. (2347 m) it will be less than 10%. High altitude adjustment must not be made on appliances operating at elevations below 2500 ft. (762 m).

No orifice changes are required to adjust the Brute Deluxe appliances for high altitude. High altitude adjustment is accomplished by adjustment of the gas valve manifold pressure and the air shutter(s). The required instruments used to assist in these adjustments are a CO2 or O2 Analyzer and a U-Tube Manometer or other device capable of reading a pressure of 2.5-3.0 inches W.C. (0.62-0.75 kPa).

Start the adjustment process by checking the CO2 in the “as installed” condition. Adjust the air shutter(s) so that the CO2 is about 8% or the O2 is about 6.8% for appliances operating on Natural Gas. For appliances operating on LP Gas adjust the air shutter(s) so that the CO2 is about 9.2% or the O2 is about 6.8%. Appliances with two blowers should be adjusted so that the air shutters below each blower are open the same amount.

Once the CO2 or O2 has been set, the manifold pressure may be adjusted. Remove the 1/8 NPT plug from the lower side of the gas valve that is to be set and install a fitting, hose and manometer. Start the appliance and observe the manifold pressure. Manifold pressure must be adjusted to 3.0 in. W.C. (0.75 kPa) (for high altitude only, standard operating pressure is 2.5 in. W.C. (0.62 kPa)). It is adjusted by removing the slotted cap on the gas valve and turning the adjustment screw (beneath the cap) clockwise to increase pressure and replaced after the adjustments have been completed and the fitting, hose and manometer have been removed and the 1/8" plug has been replaced. Repeat this process until all gas valves have been set. Note: The pressure can be set only when the appliance is operating and only when the particular gas valve being adjusted is energized by a call for heat from the staging control.

After all of the gas valve manifold pressures have been set, the CO2 or O2 must be reset. CO2 or O2 will have changed when the manifold pressure was adjusted. Open the air shutter(s) to reduce the CO2 or O2 to the values achieved previously.

The procedure is complete when all gas valves are adjusted to a manifold pressure of 3.0 in. W.C. (0.75 kPa) and the CO2 is adjusted to 8.0% for Natural Gas