Raypak VERSA 155C - Manual (Page 23)

PILOT SAFETY (Millivolt System)
The heaters equipped with the standing pilot
(millivolt system), have pilot generators which act as a
safety device to shut off the flow of gas to the main
burners and the pilot burner in case the pilot flame is
extinguished. The pilot burner must be manually re-
lighted to place the heater in operation again. Refer to
the lighting instructions provided on the heater label.
PILOT SAFETY (IID Units) ELECTRIC IGNITION
The heater employs a pilot safety which closes the
main gas valve within 8/10ths of a second whenever the
pilot flame is interrupted. Pilot flame is automatically lit
when the device is powered. Unit performs its own
safety check and opens the main valve only after the
pilot is proven to be lit.
BURNER DRAWER 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 (2) screws that mount burner tray to unit,
and (2) screws that secure gas valve to jacket.
6. Disconnect wires that terminate at gas valve.
7. Slide out burner tray.
8. Reverse above procedure to reinstall.
GAS VALVE REMOVAL
1. Shut off gas supply to the heater. Remove gas
piping 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.
MAIN BURNER AND ORIFICE REMOVAL
1. Remove burner drawer. See burner drawer
removal procedure.
2. Remove screws and burner hold down bracket.
NOTE: If the heat exchanger is sooted badly, the
burner hold down bracket and spacer can become
distorted from direct flame impingement and this usu-
ally necessitates replacement of these parts.
23
Burner Hold Down Bracket
Burners
HONEYWELL PILOT ROBERTSHAW PILOT
Air
Opening
Pilot
Orifice
Orifice
Pilot
Fig. # 8057.0
Fig. # 8045.1 Fig. # 8102.0
3. Lift burners from slotted spacers and slide from
orifices. Clean with a wire brush.
4. Orifices usually do not need to be replaced. To
clean, run either copper wire or wood toothpick
through orifice. Do not enlarge hole. To remove
orifice, use a socket wrench and remove from
manifold. DO NOT overtighten when reinstalling.
PILOT REMOVAL AND CLEANING
1. Disconnect pilot tubing, and wires from gas valve.
2. Remove pilot assembly from burner tray.
3. Remove pilot from bracket.
4. Remove pilot orifice and air opening (Honeywell
MV unit only), and clean with wire or small brush.
CAUTION! Do not enlarge hole in pilot orifice.
5. Reverse above procedure to reinstall.