Swimming Pool Blog


Hayward Pool Heater Troubleshooting

Hayward Pool Heater Troubleshooting
by Mark Garcia February 24, 2015

When it comes to troubleshooting Hayward pool heaters, there's not too much difference between the problem solving process for other gas-fired heaters, made by Jandy, Pentair or Raypak. The components of a Hayward pool heater are also very similar to gas heaters made by other manufacturers.

To troubleshoot a gas-fired appliance, you have to think like a "combustioneer". Gas fired pool heaters are very similar in operation to a home gas-fired furnace, with the main difference being that a pool heater heats water and a home furnace heats air. Big difference, but other than that, they operate pretty much the same.

Here's two charts for Hayward pool heater troubleshooting, the first is for millivolt heaters and the one further down is for electronic or digital heaters, those that give an error code on display. 

 

HAYWARD MILLIVOLT POOL HEATER TROUBLESHOOTING GUIDE

Troubleshooting chart for Hayward Universal H-Series millivolt pool heaters, with standing pilot, models H150, H200, H250, H300, H350, H400

PROBLEM PRESENTING
PROBABLE CAUSES POSSIBLE SOLUTIONS
HEATER CYCLES ON & OFF DIRTY FILTER OR PUMP BASKET CLEAN FILTER OR BASKETS
  EXTERNAL BYPASS OUT OF ADJUSTMENT ADJUST BYPASS VALVE
  INTERNAL BYPASS BROKEN OR STUCK INSPECT/REPAIR BYPASS
  PRESSURE SWITCH OUT OF ADJUSTMENT ADJUST PRESSURE SWITCH
  LIME SCALE IN HEAT EXCHANGER CLEAN OR REPLACE H.E.
   
SOOTING OF HEAT EXHANGER  HIGH WATER FLOW INTO HEATER >125 GPM  INSTALL EXTERNAL BYPASS
   INTERNAL BYPASS BROKEN OR STUCK  INSPECT/REPAIR BYPASS
   LACK OF AIR COMBUSTION  IMPROVE AIR FLOW TO HEATER
   LOW GAS PRESSURE  CHECK GAS LINE SIZE
   IMPROPER VENTING  INSPECT CORRECT EXHAUST
   BLOCKED HEAT EXCHANGER  CLEAN HEAT EXCHANGER
   BLOCKED BURNERS  CLEAN DEBRIS ON BURNERS
   
PILOT OUTAGES  LOW GAS PRESSURE  INCREASE PILOT GAS PRESSURE
   RESTRICTED GAS FLOW  CLEAN PILOT ORIFICE
   WEAK THERMOPILE <400mv output  REPLACE THERMOPILE
   HIGH WINDS  INSTALL HIGH WIND STACK
   BROKEN PILOT GAS TUBING  REPLACE PILOT TUBING
   STUCK GAS VALVE  REPLACE GAS VALVE
   
LIME SCALE IN HEAT EXCHANGER  INTERNAL BYPASS BROKEN OR STUCK  INSPECT/REPAIR BYPASS
 THERMAL CONTROL VALVE BROKEN  TEST IN PAN OF BOILING WATER
 POOR WATER CHEMISTRY  ADJUST WATER BALANCE
 EXTERNAL BYPASS OUT OF ADJUSTMENT  ADJUST BYPASS VALVE
   
HEATER WILL NOT BRING POOL TO DESIRED TEMP
 
 
 
 
 
HEATER TOO SMALL ADD SOLAR COVER
STARTING TEMPERATURE TOO LOW ADD SOLAR COVER
POOL PUMP NOT RUNNING LONG ENOUGH CHECK TIME CLOCK
DIRTY FILTER OR PUMP BASKET CLEAN FILTER OR BASKETS
THERMOSTAT OUT OF ADJUSTMENT ADJUST/REPLACE THERMOSTAT
BAD WIRING / BAD CONNECTIONS CHECK WIRING / CONNECTIONS
WATER FLOW IS TOO LOW ADJUST BYPASS FOR MORE FLOW
   
 HEATER WON'T FIRE OR LIGHT BAD GAS VALVE USE JUMPER WIRE TO JUMP ACROSS
"TH" TERMINALS ON GAS VALVE
BAD PRESSURE SWITCH USE JUMPER WIRE TO JUMP ACROSS WIRES ON PRESSURE SWITCH
BAD THERMOSTAT USE JUMPER WIRE TO JUMP ACROSS WIRES ON THERMOSTAT
BAD HIGH LIMITS USE JUMPER WIRE TO JUMP ACROSS WIRES ON HIGH LIMITS
BAD ON/OFF SWITCH USE JUMPER WIRE TO JUMP ACROSS WIRES ON ON/OFF SWITCH
  BAD FIREMAN'S SWITCH USE JUMPER WIRE TO JUMP ACROSS FIREMAN'S SWITCH ON TIMECLOCK
   

 

HAYWARD DIGITAL POOL HEATER TROUBLESHOOTING GUIDE

Troubleshooting chart for Hayward Universal H-Series electronic pool heaters with a digital display, models H150, H200, H250, H300, H350, H400

CODE FAULT DIAGNOSIS POSSIBLE SOLUTIONS
LO PRESSURE SWITCH VERIFY PUMP IS RUNNING TURN PUMP ON
CHECK SWITCH WIRING & CONNECTIONS INPSECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION
MEASURE SWITCH CONTINUITY REMOVE WIRES AND MEASURE OHMS WITH PUMP ON; IF CLOSED - SWITCH IS OK. IF OPEN, RECONNECT WIRES & PROCEED.
CHECK WATER FLOW CLEAN FILTER, PUMP BASKETS, IMPELLER FOR BLOCKAGE.
ADJUST PRESSURE SWITCH TURN ADJUSTMENT SCREW 1 TURN CLOCKWISE, TO SEE IF LO ERROR CODE CLEARS.
DEFECTIVE PRESSURE SWITCH REPLACE PRESSURE SWITCH
   
AUTOMATIC TEMP LIMITER SWITCH CHECK SWITCH WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
MEASURE SWITCH CONTINUITY REMOVE WIRES AND MEASURE OHMS WITH PUMP ON; IF CLOSED - SWITCH IS OK. IF OPEN, RECONNECT WIRES & PROCEED.
HIGH WINDS DOWN DRAFTING CHECK FOR HIGH WINDS, IF PRESENT, INSTALL HIGH WIND STACK
CHECK FOR RESTRICTED OR BLOCKED EXHAUST FOR INDOOR UNITS OR UNITS WITH STACK, INSPECT FOR BIRD'S NESTS OR EXCESSIVE COBWEBS
CHECK FOR SOOTED OR DAMAGED HEAT EXCHANGER REMOVE TOP TO INSPECT HEAT EXCHANGER FOR HEAVY BLACK SOOT, LEAF DEBRIS OR LIME DEPOSITS
TEMPERATURE LIMITER SWITCH IS DEFECTIVE REPLACE TEMPERATURE LIMITER SWITCH
   
MANUAL TEMP LIMITER SWITCH CHECK SWITCH WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
MEASURE SWITCH CONTINUITY REMOVE WIRES AND MEASURE OHMS WITH PUMP ON; IF CLOSED - SWITCH IS OK. IF OPEN, RECONNECT WIRES & PROCEED.
HIGH WINDS DOWN DRAFTING CHECK FOR HIGH WINDS, IF PRESENT, INSTALL HIGH WIND STACK
CHECK FOR RESTRICTED OR BLOCKED EXHAUST FOR INDOOR UNITS OR UNITS WITH STACK, INSPECT FOR BIRD'S NESTS OR EXCESSIVE COBWEBS
CHECK FOR SOOTED OR DAMAGED HEAT EXCHANGER REMOVE TOP TO INSPECT HEAT EXCHANGER FOR HEAVY BLACK SOOT, LEAF DEBRIS OR LIME DEPOSITS
RESET SWITCH RESET SWITCH, IF TRIPS AGAIN, REPLACE SWITCH
TEMP LIMITER SWITCH IS DEFECTIVE
 
REPLACE TEMPERATURE LIMITER SWITCH
 
   
LIMIT SWITCH FAULT CHECK SWITCH WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
MEASURE SWITCH CONTINUITY REMOVE WIRES AND MEASURE OHMS WITH PUMP ON; IF CLOSED - SWITCH IS OK. IF OPEN, RECONNECT WIRES & PROCEED.
CHECK WATER FLOW VERIFY THAT WATER FLOW RATE IS >25 GPM MINIMUM
LIMIT SWITCH IS DEFECTIVE REPLACE LIMIT SWITCH
 
BO BYPASS OPERATION CHECK #2 DIP SWITCH ON BACK OF CONTROL MODULE #2 DIP SHOULD BE ON FOR REMOTE OPERATION. MOVE TO OFF IF NO REMOTE CONTROL IS USED.
 
IF IGNITION FAILURE ENSURE GAS SUPPLY VALVES ARE OPEN CHECK THAT GAS METER, GAS REGULATOR AND GAS VALVE ARE ALL OPEN
CHECK FOR LOW GAS SUPPLY INLET GAS PRESSURE MUST EXCEED MINIMUM ON RATING PLATE.
CHECK IGNITER WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
CHECK GAS VALVE WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
GAS VALVE FAILURE MEASURE VOLTAGE ACROSS GAS VALVE DURING IGNITION. IF 24V, BUT VALVE DOES NOT OPEN, REPLACE GAS VALVE.
GAS VALVE RELAY FAILURE MEASURE VOLTAGE ACROSS GAS VALVE DURING IGNITION. IF 24V IS NOT PRESENT, REPLACE RELAY.
 

SF
TEMPERATURE SENSOR INPUT FAILURE CHECK SENSOR WIRING & CONNECTIONS INSPECT WIRES FOR KINKS OR RODENT DAMAGE. INSPECT TERMINALS FOR BREAKAGE OR CORROSION.
SENSOR DEFECTIVE REPLACE TEMPERATURE SENSOR
 
HS OVERHEATING POOL WATER TEMP > 104° VERIFY REMOTE THERMOSTAT SET POINT
CHECK WATER FLOW VERIFY THAT WATER FLOW RATE IS >25 GPM MINIMUM
 
HF FLAME SENSE FAULT FLAME SENSE FAILURE REPLACE IGNITER
 

 

I hope that these charts are helpful in solving your Hayward pool heater problems. Pool heaters can be the most baffling piece of pool equipment, but if you think like a combustioneer, and consider the proper flow of gas, water and electric, you're sure to find a solution quickly.

Troubleshooting pool heaters is a methodical process; or a process of elimination really. First eliminate water flow issues, then gas flow issues, and finally the low voltage electric currents that run between pool heater components. And if you have Hayward heater error codes on display, that makes finding the problem almost easy!

Oh, I almost forgot, if you need any Hayward Pool Heater Parts, you know where to find them! :-)

 

Thanks for Reading!
Mark Garcia

 



{Ratings}