Raypak RAYTHERM 133-4001, Installation & Operating Instructions Manual

Page: 46 / 52

46
COMBINATION FLAME SENSOR/
IGNITER AND PILOT BURNER
Fig. 38: Typical Burner Tray Illustrated
burner Tray Removal
1. Shut-off power and gas supply to the heater.
Disconnect union(s) and pilot tubing, then loosen
and remove burner hold-down screws.
2. Disconnect wires at gas valve and slide burner
drawer out.
Gas Valve Removal
1. Shut-off gas supply to the heater. Remove gas pip-
ing to gas valve inlet.
2. Disconnect wires, pilot tubing and bleed line, if
required.
3. Turn vertical gas pipe from manifold slightly and
unscrew gas valve.
4. Reverse above procedure to re-install.
Gas Valve Adjustment - Robertshaw
(Invensys) 7000 Series 2-Stage Gas
Valve with Solenoid Valve
1. Turn the heater off.
2. Remove the 3/8” nut or the #10 Torx screw.
3. Lift solenoid valve up, keeping the wires connect-
ed to the solenoid valve.
4. If only low fire adjustment is needed, go to Step 9.
5. Using a 3/8” wrench, carefully remove the alu-
minum cap that was under the solenoid
valve-count # of turns when removing the cap.
Be careful not to drop the cylinder (weight) or the
small spring that is under the cap –see Fig. 39.
6. Remove the spring and store in a safe place.
7. Using an Allen wrench, turn the screw clockwise to
increase or counterclockwise to decrease high fire
manifold pressure –see Fig. 39.
8. Install the spring, weight and aluminum cap –tight-
en the cap using same # of turns as was used in
removing the cap.
9. For low fire adjustment, tighten the aluminum cap
to increase and loosen to decrease low fire mani-
fold pressure.
10. Install 2-stage solenoid valve and turn heater on,
check manifold pressures.
11. Repeat steps 3 to 10 until correct manifold pres-
sures are obtained.
12. Secure 2-stage solenoid valve by tightening the
3/8” nut or #10 Torx screw.
Fig. 39: 2-Stage Gas Valve Adjustment (Invensys)
NOTE:
Attach a manometer and check the manifold
pressures –both high fire and low fire– before
making any adjustments.