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Page 30

Copper Brute B4 Volume Water Heaters

Page 31

Thermocouple

Thermocouple

Adapter

Gas Valve

Millivolt

Meter

Pilot

1.      If the heater stays on with the brown wire on the 

gas valve disconnected, replace the gas valve 

(see Section 4.2).

 

Never attempt to repair the gas valve. Such 

attempts will void the warranty, and could lead to 

dangerous results. 

2.      Check electrical components for loose wires. 

Disconnect one of the lead wires on the gas 

valve. If the heater goes off, the wiring could be 

at fault. Repair or replace as necessary.

The main burners cycling on and off can be 

caused by:
1.      Poor wind conditions on an outdoor installation.
2.      Pilot components out of position.
3.      Low gas pressure causing an improper pilot 

flame. 
The pilot flame may appear to be all right until 

the main burners come on, then the pilot flame shrinks. 

An undersized gas supply line may cause this. 

The terminal strip has been included so the 

heater can be operated by various external controls not 

provided by Bradford White. Determine whether or 

not an external control is open by checking for voltage 

at each terminal. If there is voltage at one terminal 

and not the other, examine the external control. It may 

require service or replacement. 

1.      Check all wire connections, ignition cable, and 

using a mirror, make sure there is a pilot flame. 

2.      If everything appears all right, measure flame 

sensing current by connecting a direct current 

(DC) microamp meter between terminal No. 

12 and the GND (BURNER) terminal on the 

ignition control (see Figure 43).

NOTE: Separate the microamp meter leads from 

each other and clear the heater chassis for most of their 

length to properly perform this test.

3.      When the pilot lights, the microamp meter should 

read 1.5 microamps or more with or without the 

main burners firing. A smaller current could be 

caused by poor pilot flame, the position of the 

pilot electrode, or bad cable and connectors.

4.      If the pilot flame and sensor electrode are all 

right, but there is no main burner ignition, clip 

one lead from a volt meter between the yellow 

wire terminal on the transformer and the brown 

wire terminal on the gas valve. 

5.      If the voltmeter reads between 20 to 28VAC, 

but the main burners do not fire, replace the gas 

valve (see Section 4.2).

If the pilot flame and pilot thermocouple 

generator are all right, but there is no main burner 

ignition:
1.      Clip one lead of a volt meter between the yellow 

wire on the transformer and the brown wire 

terminal on the gas valve. 

2.      If the volt meter reads between 20 to 28VAC, 

but the main burners do not fire, replace the gas 

valve (see Section 4.2).