Rinnai RHFE-551FA Service Manual page 18

Lock Out Checklist
10. Check resistance on all three gas solenoid valve coils. Unplug each coil before reading resistance. Set
your meter on the 2k scale, you should read somewhere between 1,200 to 1,900 ohms across SV1 and SV2.
Coils SV1 and SV2 each have (1) yellow and (1) black wire. The POV valve with two gray wires should read
somewhere between 80 - 100 ohms of resistance. Next plug the coils back up and turn the unit on. When the
unit is going through the ignition cycle you should have 90 VDC to SV1 and SV2 solenoids. Make sure you
have your meter set to read 100 VDC. Across the POV coil you will read somewhere between 1 - 35 VDC. If
the unit goes to lockout before you have time to read all the coils, you may have to cycle it two or three times.
11. Check for voltage and resistance readings across transformer listed below. Remember any time you are
taking resistance readings, disconnect power to the unit and isolate item being checked.
Across the two white wires you should have 100 VAC or 11.2 ohms.
Across the two red wires you should have 30 VAC or 1.6 ohms.
Across the black and blue wires you should have 13.5 VAC or 1.4 ohms.
Across the blue and yellow output wire from the transformer you should have 155 VAC or 250 ohms.
Across the two gray wires you should have 120 VAC or 12 ohms.
12. Ensure the vent assembly does not exceed thirteen feet and two elbows. Maximum vertical run is eight
feet, then the vent must run horizontal.
13. Ensure jumper for vent extension on rear of your unit is connected to proper terminals. Terminals 2 and 3
are for direct vent, terminals 1 and 2 are used for vent extension of four feet or more.
14. Check thermistor by inserting meter leads into each end of the thermistor plug. Set your meter to the
200k scale and read resistance. You should be able to apply heat to the thermistor bulb and see the
resistance decrease, then place some ice to thermistor and the resistance should increase.
15. Check flame rod circuit on low fire. Cycle unit down to low flame for ten minutes then take flame circuit
reading. The reading should be above 1.2 micro amps.
16. Ensure unit is plugged into a properly grounded outlet. Do not assume you have a ground, check with
your voltage meter.
17. Check for proper polarity of the receptacle.
18. Check ignition circuit, when unit is in the process of ignition, you should have 100 VAC across the blue
and red wires connected to the ignition module.
19. Check for frozen regulators in supply lines.
20. If further assistance is needed, please contact your distributor. If they are unable to assist you with repairs,
contact Rinnai America's service department at 1-800-621-9419.
NOTE: Before any items/products are to be returned to Rinnai, you must first obtain a return authorization
number. Any items returned without this number will be returned at owner's/shipper's expense.
18 Rinnai Direct Vent Service Manual
RHFE-431FA Series