John Wood Atmospheric Gas (Standard) - Manual (Page 25)

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TEMPERATURE AND PRESSURE
RELIEF VALVE
DISCHARGE LINE TO DRAIN
MANUAL RELIEF
VALVE
FIGURE 19.
6. Disconnect the white and red wires from the gas
control valve/thermostat (Figure 20). Use needle nose
pliers to grip the connector(s). IMPORTANT: Grip the
connector carefully to prevent damage. Do not grip or
pull the wires themselves.
7. Grasp the manifold tube and push down slightly to free
the manifold tube and pilot tube.
8. Remove the screws (SAE 1/4” nut driver) securing the
manifold/burner assembly to the combustion chamber.
See Figure 21.
9. Carefully remove the manifold/burner assembly from
the combustion chamber. BE SURE NOT TO DAMAGE
ANY INTERNAL PARTS.
MANIFOLD SCREW (2)
MANIFOLD COMPONENT BLOCK
MANIFOLD DOOR
THERMAL SWITCH
PILOT TUBE MANIFOLD TUBE
VIEWPORT
THERMOPILE AND
SWITCH WIRE
CONNECTIONS
PIEZO IGNITER BUTTON
GAS CONTROL VALVE/THERMOSTAT
GAS CONTROL/
TEMPERATURE KNOB
VAC
OUTER DOOR
NOT SHOWN
FIGURE 21.
Removing the Burner from the Manifold/
Burner Assembly
Natural Gas (Low Nox) & L.P. Gas Burner
1. Take off the burner by removing the two (2) screws
located underneath the burner.
2. Check the burner to see if it is dirty or clogged. The burner
may be cleaned with soap and hot water (Figure 22).
IMPORTANT: DO NOT remove the orifice.
BURNER
(BOTTOM VIEW)
SCREWS
PILOT ASSEMBLY
(BOTTOM VIEW)
FIGURE 22.
Replacement Parts
IMPORTANT: The following maintenance procedures are
for the FVIR System components and should be performed
by a qualified technician.
Replacement parts may be ordered through your plumber
or the local distributor. Parts will be shipped at prevailing
prices and billed accordingly. When ordering replacement
parts, always have the following information ready:
1. model, serial, and product number
2. type of gas
3. item number
4. parts description
See Repair Parts Section for a list of available repair parts.
Removing the Manifold/Burner Assembly
1. Turn the gas control/temperature knob to the “OFF”
position (Figure 20).
2. Before performing any maintenance, it is important to turn
off the gas supply to the water heater at the manual gas
shut-off valve. This valve is typically located beside the
water heater. Note the position of the shut-off valve in the
open/on position, then proceed to turn it off (Figure 3).
3. With the unit shut-off, allow sufficient time for the water
heater to cool before performing any maintenance.
IGNITER
WIRE
RED WIRE
(LEFT SIDE)
PILOT
TUBE
MANIFOLD TUBE
IGNITER
BUTTON
IGNITER
LEAD
WIRE
WHITE
WIRE
(RIGHT
SIDE)
GAS CONTROL/
TEMPERATURE KNOB
VAC
FIGURE 20.
4. Remove the outer door.
5. Disconnect the following from the gas control valve/
thermostat: pilot tube (SAE 7/16” wrench), igniter wire
(from the igniter lead wire), and manifold tube (SAE 3/4”
wrench). See Figure 20.
NOTE: L.P. Gas systems use reverse (left-hand) threads
on the manifold tube.
properly. To prevent water damage, the valve must be
properly connected to a discharge line which terminates at
an adequate drain. Standing clear of the outlet (discharged
water may be hot), slowly lift and release the lever handle
on the temperature and pressure relief valve to allow the
valve to operate freely and return to its closed position.
See Figure 19. If the valve fails to completely reset and
continues to release water, immediately shut off the
manual gas control valve and the cold water inlet valve
and call a qualified technician.
MAINTENANCE OF YOUR WATER HEATER