Pool & Spa Heaters

ELECTRICAL TROUBLESHOOTING055, 105 & 155 Models If the pool/spa water is too cold, troubleshoot the system as follows:Check voltage at 24 V terminals.VOLTAGE BETWEEN 21.5-28.5 V.Set control to max. temperature. After 2-3cycles, check water temperature.TEMPERATURE BELOW 40°CDisconnect sensor leads from circuit board.Measure sensor resistance with ohmmeter.RESISTANCE 1-14k OHMS.Check water temperature; estimate expected sensorresistance from chart below.MEASURED AND ESTIMATED RESISTANCEMATCH WITHIN 20 PERCENT.Disconnect potentiometer leads from circuit board.Measure resistance with ohmmeter. If resistance is:0-100 ohms at minimum setting;9k to 11k at maximum setting, replace circuitboard.Above 11k ohms but less than15 k ohms, replace potentiometer.Above 15k ohms, fix loose or broken wires;replace potentiometer if necessary. Reconnectall leads and check out system.Check voltage at 24 V terminals.VOLTAGE OUTSIDE RANGE 21.5-28.5 V.Check transformer, 230 V supply, correct as necessary.If230 V side of transformer is open circuit, checkcombustion chamber for heat leaksCheck 3 Amp fuse.TEMPERATURE 40°C-40.5° C.Control ok.If the pool/spa/hot tub water is too hot, troubleshoot the system as follows:RESISTANCE 0 OHMS (SHORT CIRCUIT)Check system for shorted wires or open circuits.Replace sensor if necessary.MEASURED AND ESTIMATED RESISTANCEDON'T MATCH.Replace sensor. Reconnect all leads and checkout system.VOLTAGE BETWEEN 21.5-28.5 V.Set control to max. temperature. After 2-3cycles, check water temperature.TEMPERATURE ABOVE 42°CDisconnect sensor leads from circuit board.Measure sensor resistance with ohmmeter.RESISTANCE 1-14k OHMS.Check water temperature; estimate expectedsensor resistance from chart below.MEASURED AND ESTIMATED RESISTANCEMATCH WITHIN 20 PERCENT.Disconnect potentiometer leads from circuit board.Measure resistance with ohmmeter. If resistanceis:0-100 ohms at minimum setting:9k to 11k at maximum setting,replace circuit board.VOLTAGE OUTSIDE RANGE 21.5-28.5 V.Check transformer, 230 V supply, correct as necessary.If 230 V side of transformer is open circuit, checkcombustion chamber for heat leaksCheck 3 Amp fuse.TEMPERATURE 40°C-40.5° CControl ok.RESISTANCE ABOVE 15k OHMS (OPENCIRCUIT) OR SHORT CIRCUIT.Fix loose or broken wires. Replace sensor ifnecessary.MEASURED AND ESTIMATED RESISTANCEDON'T MATCH.Replace sensor. Reconnect all leads and checkout system.Above 11k ohms, replace potentiometer.0 ohms (short circuit), replace potentiometer.Reconnect all leads and check out system.SENSOR RESISTANCE AT VARIOUS TEMPERATURESTemperature (deg C) 16°C 20°C 21°C 25°C 30°C 31°C 35°C 40°C 41°C(deg. F) 61 68 70 77 86 88 95 104 106Resistance (k ohms) 14.9 12.5 11.9 10.0 8.1 7.7 6.5 5.3 5.13327-01-04