HELLO EVERYONE,
I'M NEW TO BOILER REPAIRS(I'M AN INSTALLER).THIS IS MY FIRST POST.PUMA 80(PERMANENT PILOT) FIRES UP FULL FLAME FOR HOT WATER.THE BURNER DOESN'T MODULATE DOWN TO LOW FLAME AND THE BURNER FLAME CUTS OUT.THE WATER GOES COLD AND THEN THE BOILER IGNITES AGAIN...THE CYCLE GOES ROUND AND ROUND.I'VE TRIED DISCONNECTING ONE OF THE LEADS ON THE MODULATION ON THE GAS VALVE WHEN RUNNING THE HOT TAP AND THE FLAME CUTS OUT THEN GOES TO LOW FLAME.I HAVE CHANGED THE H/W THERMISTOR AND THE USER DISPLAY BOARD(BOTH DONE NOTHING TO HELP).THE POTENTIAL DIAL ON THE FRONT OF BOILER FOR THE H/W HAS NO EFFECT WHEN TURNING UP OR DOWN ON THE FLAME?THE PRESSURE IS GOOD ON THE HOT WATER SIDE(I KNOW IT'S A COMBINED HEAT EXCHANGER AND THIS COULD BE THE PROBLEM?)I'M NOW LEFT TO THINK MODULATION PCB OR HEAT EXCHANGER SCALED?ALSO THE PUMP HAD A VERY LOW RESISTNCE OF ONLY 50 OHMS....HELP
AS I SAID I'M VERY NEW TO BREAKDOWN SO FORGIVE MY KNOWLEDGE AND ANY SILLY POINTS I MAY HAVE MADE,THANKS BRAD.
I'M NEW TO BOILER REPAIRS(I'M AN INSTALLER).THIS IS MY FIRST POST.PUMA 80(PERMANENT PILOT) FIRES UP FULL FLAME FOR HOT WATER.THE BURNER DOESN'T MODULATE DOWN TO LOW FLAME AND THE BURNER FLAME CUTS OUT.THE WATER GOES COLD AND THEN THE BOILER IGNITES AGAIN...THE CYCLE GOES ROUND AND ROUND.I'VE TRIED DISCONNECTING ONE OF THE LEADS ON THE MODULATION ON THE GAS VALVE WHEN RUNNING THE HOT TAP AND THE FLAME CUTS OUT THEN GOES TO LOW FLAME.I HAVE CHANGED THE H/W THERMISTOR AND THE USER DISPLAY BOARD(BOTH DONE NOTHING TO HELP).THE POTENTIAL DIAL ON THE FRONT OF BOILER FOR THE H/W HAS NO EFFECT WHEN TURNING UP OR DOWN ON THE FLAME?THE PRESSURE IS GOOD ON THE HOT WATER SIDE(I KNOW IT'S A COMBINED HEAT EXCHANGER AND THIS COULD BE THE PROBLEM?)I'M NOW LEFT TO THINK MODULATION PCB OR HEAT EXCHANGER SCALED?ALSO THE PUMP HAD A VERY LOW RESISTNCE OF ONLY 50 OHMS....HELP
AS I SAID I'M VERY NEW TO BREAKDOWN SO FORGIVE MY KNOWLEDGE AND ANY SILLY POINTS I MAY HAVE MADE,THANKS BRAD.