Paloma PH2-20R DVSN, Engineering Handbook

Page: 13 / 172

SVC 820-Tankless Gas Trouble Shooting Manual Page | 13
13
34 Ambient Thermistor
1. Check Thermistor wiring for damage
2. Check and clean Ambient Thermistor
3. Ohm Thermistor
If wiring and component readings are normal:
1. Check for restrictions in airflow around unit and vent terminal
2. Ensure fan blade is tight on motor shaft and spins freely
35
Improper Thermistor
Connection
1. Check that all Thermistors are secured to proper connections on Control
Board
2. Check that all quick connectors between Control Board and Thermistors
51 Gas Control Valve
1. Check Gas Control Valve wiring harness for loose or damaged terminals
2. Ohm Gas Control Valve
52
PGFR Valve
(Modulating Valve) 1. Check PGFR Valve wiring harness for loose or damaged connections
2. Ohm PGFR Valve
61
Installation/Maintenance:
Blower Motor
1. Ensure Blower Motor will turn freely. Motor will operate with a small amount
of restriction
2. Check wiring harness to Motor for damaged and/or loose connections
3. Check venting length not to exceed max lengths and bends
65 Water Control Valve
1. Check Water Control Valve wiring harness for loose or damaged terminals
2. Check for proper voltage to Water Control Valve
66 Water Bypass Valve
1. Check Water Bypass Valve wiring harness for loose or damaged terminals
2. Check for proper voltage to water by-pass solenoid
71 Gas Control Valve
1. Check Gas Control Valve wiring harness for loose or damaged terminals
2. Ohm Gas Control Valve
72
Flame Rod
(Detected False Flame)
1. Ensure Flame Rod(s) is touching flame when unit fires
2. Check inside burner chamber for any foreign material blocking flame at Flame
Rod(s)
3. Check all wiring to Flame Rod for damage
4. Check Flame Rod for proper voltage
5. Remove Flame Rod and check, clean with steel wool (Do not use sandpaper)