Rinnai RHFE-551FA Service Manual page 27

Lockout 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, (pins 21 and 27) you should have 98 ~ 105 VAC or 6 ~ 8 ohms.
Across the two red wires, (pins 30 and 31) you should have 28 ~ 50 VAC or 1 ~ 3 ohms.
Across the black and blue wires, (pins 22 and 23) you should have 10 ~ 15 VAC or 0.5 ~ 2.4 ohms.
Across the blue and yellow wires, (pins 23 and 32) you should have 130 ~ 185 VAC or 200 – 400 ohms.
Across the two gray wires, (pins 17 and 18) you should have 110 ~ 120 VAC or 10 ~ 14 ohms.
___ Across the two purple wires, (pins 24 and 25) you should have 4.5 ~ 6 VAC or 1 ~ 2 ohms.
___ Across the purple and brown wires, (pins 24 and 28) you should have 2 ~ 3 VAC
___ Across the black and yellow wires, (pins22 and 32) you should have 160 ~ 180 VAC or 200 ~ 212 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. 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.
14. 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.
15. Ensure unit is plugged into a properly grounded outlet. Do not assume you have a ground, check with
your voltage meter.
16. Check for proper polarity of the receptacle.
17. 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.
18. Check for regulators that may be freezing up in supply lines.
Rinnai Direct Vent Service Manual
RHFE-431WTA
RHFE-556WTA
27