Raypak 106, User'S Installation And Operation Manual

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7.1.4.  Flame Roll-Out Safety Switch

Heaters  are  equipped  with  a  thermal  cutoff  device  to 

prevent  flame  roll-out  in  the  event  the  heat  exchanger 

becomes blocked. This is a “single-use” type fusible link 

or  thermal  fuse,  that  must  be  replaced  when  disabled 

by  an  over-temperature  condition,  caused  by  excessive 

restriction  in  the  heat  exchanger  flue  passage,  roll-out, 

high winds, etc.

7.1.5.  High Limits

The  heater  is  equipped  with  two  automatic  high  limits. 

Both are located in the In/Out header. Both are set to open 

at 135°F (57°C).

NOTE:

 An erratic high limit is often characteristic of an 

internal heat exchanger problem, e.g. scale build-up, 

defective bypass. Refer to Troubleshooting section.

7.1.6.  High Limit Removal

1.  Shut off main electrical power switch to heater.
2.  Remove rear In/Out inspection panel.
3.  Remove defective high limit and replace with a new 

high limit.

4.  Replace inspection panel.

Figure 39.  High Limit Switch

7.1.7.  Burner Tray Removal

1.  Shut off main electrical power switch to heater.
2.  Shut off gas upstream of heater.
3.  Remove front door
4.  Disconnect gas line from gas valve. 
5.  Remove (3) screws holding the anti-rotation bracket 

in place. 

6.  Remove bracket an set aside. 
7.  Remove (4) screws as shown in the image.
8.  Disconnect wiring from gas valve. 
9.  Remove (2) screws holding the control panel up.
10.  Flip the control panel forward. 
11.  Disconnect  ignition  wire  and  remove  with  burner 

tray. 

12.  Reverse above procedure to reinstall.

Figure 40.  Burner Tray Assembly

7.1.8.  Gas Valve Removal

1.  Remove burner tray.
2.  Disconnect pilot tubing from gas valve
3.  Rotate  the  gas  valve  counter  clockwise  to  remove 

valve from nipple. 

4.  Reverse above procedure to reinstall.

SCREWS HOLDING 

TRAY IN PLACE

Figure 41.  Gas Valve Removal

7.1.9.  Pilot Removal and Cleaning 

1.  Remove burner tray from heater
2.  Disconnect tubing from gas valve.
3.  Remove (2) screws holding pilot bracket in place.
4.  Remove the pilot assembly by pushing the pilot
5.  Remove the locating pilot screw from the bracket to 

release the pilot assembly.

6.  Reverse above procedure to reinstall