Bradford-White Corp BWCV Manual De Usuario

Internet Version for Reference Only

Page 34

Copper Brute II

Page 35

10.    Inspect the inside of the copper tubes for scale 

buildup. Scale can build up on the inner surface 

of the heat exchanger tubes, which can restrict 

water flow. If the tubes show signs of scaling, 

clean the internal surface. Bradford White offers 

a tube cleaning kit part number R0010000.

11.    Reassemble in the reverse order, and check 

appliance operation after start-up.

There are many causes of lockouts. The three 

most common causes are: (1) inadequate gas supply, 

(2) poor combustion, (3) ignitor failure.

1.      Inadequate gas supply: Before proceeding, ensure 

that the gas supply has not been shutoff or the LP 

tank (LP heaters) is not empty. Then, restart the 

heater and observe the operational cycle. After 

a 15-second fan pre-purge, the ignitor will heat 

up for 20 seconds, and then the unit will light. 

If it does not, check the gas supply pressure to 

the appliance, after resetting the appliance and 

attempting another start-up. The gas pressure to 

the appliance must be above 5" W.C. (1.2kPa) 

throughout the entire start-up cycle. If it is not, 

correct the supply problem (check gas valves or 

supply piping). If the supply pressure is adequate, 

consult the factory for assistance.

2.      Poor Combustion: Poor combustion should 

be suspected if there is a strong flue gas odor. 

The odor may result from an improper gas/air 

ratio (high or low O

2

 or CO

2

). Copper Brute II 

appliances operate best with 45% excess air (8% 

CO

2

 on natural gas, 9.2% CO

2

 on LP). Check the 

CO

2

 of the appliance and adjust if necessary.

3.      Ignitor failure: If the heater goes through a 

normal start cycle but combustion does not 

occur, ignitor failure should be suspected. Check 

the ignitor by unplugging the ignitor plug and 

measuring the ignitor resistance. It should be 

50-80 ohms. If the resistance is not 50-80 ohms, 

replace the ignitor. If the resistance is correct, 

reset the heater and check for 120 VAC at the 

ignitor plug during the start cycle. If there is no 

voltage, replace the faulty ignitor wire harness or 

the ignition control.

A defective burner can cause a delayed ignition. 

If the gas supply pressure is proper and the gas 

valves are functioning properly, then burners should 

be inspected. There should be no distortion or 

perforations in the burners outside of the active burner 

port area. Replace if indicated.

Short cycling will generally occur only in 

combination space heating and water heating 

applications when the water heater is operating in the 

space-heating mode. Because the Copper Brute II is a 

stage-fired water heater and its input will reduce when 

there is a reduction in heating load, short cycling is 

greatly reduced. If the heating load drops below the 

minimum input of the water heater for an extended 

period, the water heater will have a tendency to short 

cycle. If short cycling is frequently experienced, 

regardless of the control’s attempt to limit it, the 

heating load should be redistributed to control it. See 

Section 6.2 regarding controller setup.

If short cycling occurs in a water heater 

application, it is probably caused by undersized 

piping between the water heater and the storage tank 

or by some other factor that restricts proper water 

flow through the water heater. The cause should be 

determined and corrected. 

Appliances operating with an improper air/fuel 

ratio are very inefficient and consequently, have 

very high gas consumption. Because efficiency is 

high when the CO

2

 is high (or O

2

 is low), appliances 

operating with low CO

2

 or high O

2

 (especially LP 

appliances) consume more gas. Adjust the CO

2

 or O

2

 

for optimum efficiency. If no combustion analyzing 

equipment (CO

2

 or O

2

) is available then a proper 

adjustment of the air/fuel ratio (CO

2

 or O

2

) cannot be 

accomplished. However, by briefly sniffing the flue 

gases it is possible to determine if the CO

2

 or O

2

 is 

within the proper range. No significant flue gas odor 

should be detected when combustion is proper. A 

strong piercing smell indicates poor combustion and 

generally a lean mixture - low CO

2

 or high O

2 

. The 

CO

2

 should be 8% at high fire. To check the CO2, first 

verify that the supply gas pressure is within 5" to 13" 

w.c. (1.2 to 3.2 kPa) With the heater running with all 

stages firing, set the air box pressure to 1.5" w.c. (0.37 

kPa) (as a starting point), by adjusting the air shutter(s) 

at the bottom of the fan(s). Check the CO2, and adjust 

the air shutters if further adjustment to the CO2 is 

needed. Models 1250 to 2000 have two blowers and 

two air chambers (boxes). The pressure of each air box 

must be equal when the final adjustment is made.

A trouble shooting chart for the temperature 

control is shown on the following page.