Nordyne M1M, M1G, M1B, M1S owner manual Robertshaw Valve, Convertible Pressure Regulator

Robertshaw

Valve

Figure 34. Convertible Pressure

Regulator

d. To remove the gas valve assembly, remove screw(s) from gas valve bracket. Gas valve and spud may be removed. Orifice is located at the end of the spud (M1G*,M1M*),or re- move three (3) bolts from U-shaped manifold plate and orifice assembly (M1B*).

e. Replace the main orifice with the L.P. gas orifice supplied in the envelope located by the gas valve. Check to insure the orifice size matches the nameplate.

f.It is not necessary to convert the pilot orifice.

g.For Honeywell gas valves with the regulator converter (Figure 33), check for the letters NAT or LP on the pressure regulator cap. Unscrew the cap, invert it, replace, and tighten until snug.

h.For the Robertshaw gas valve with the regu- lator converter (Figure 34), remove the black cover and unscrew the converter located on top of the gas valve. Invert the converter. (For “LP” the red ring will be located at the bottom and the “LP” stamping on the con- verter will appear right side up.) Then screw converter back into the regulator, hand tight plus 1/8 turn, and replace the black cover onto the converter top to protect the threads.

i.Reassemble the burner assembly into the furnace.

j.Reconnect the gas piping and electrical wires to the gas valve.

k.Open the manual shut-off valve and follow the FURNACE START-UP procedure as outlined previously in this manual to put the furnace into operation.

NOTE: The pilot flame is adjustable by turning the adjustment screw located on the gas valve with a small screwdriver. (See Figure 29)

TROUBLESHOOTING - STANDING PILOT MODELS

Main Burner Does Not Come On

a. Check the electrical supply to the furnace. b. Be sure the furnace On-Off switch is in the

“ON” position.

c. Check for proper thermostat operation.

d. Check for broken or open thermostat wires.

e.Check to make sure the insulation located on the inside of the front panel is glued securely around the fan switch and the limit switch.

f.Shut off the electrical supply to the furnace and remove the electrical box cover.

g.Check for a defective transformer or blown fuse.

h.Check electrical circuit for proper grounding, polarity, and make sure the electrical con- nections are tight.

i.Check to see if limit switches may have failed to close.

j.Replace the electrical box cover and restore electrical power to the furnace. Turn the On- Off switch to “ON” and raise the thermostat setting above room temperature.

k.Check for 24 volts at the gas valve.

l.Replace the gas valve if the pilot is estab- lished and it does not open when powered with 24 volts.

Gas Valve Powered (24 volts)– No Main Flame

a. The manual shut-off valve must be on. b. The pilot flame must be established.

c. The gas valve control lever must be in the “ON” position.

d. Check gas pressure coming to the gas valve.

e.Replace the gas valve if the main burner does not come on under the above conditions.

Pilot Will Not Light or Goes Out a. Check the incoming gas pressure.

b. Check for the proper pilot orifice. See the nameplate SPECIFICATION.

c.Check for proper pilot flame adjustment. See

“BURNER ADJUSTMENTS.”

d.Check the thermocouple millivoltage.

•Millivoltage should read between 18 and 30 mv.

•If the closed millivolt reading is not between 18 and 30 mv., the gas valve electromagnet

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