Mastertemp 400 intermittently working/not working

[miller351]

Hello all. My Mastertemp 400 (Model: 460736) has been intermittently working and not working for the past year or 2. It goes thru a few weeks to a couple months working and the same timeframe not working. When working correctly, I hear the click from the circuit board, I hear the air flow and gas flow right after. Then it fires right up.

Now, when I turn it on, I hear a click from the circuit board, but thats it (no audible blower or gas sound. I have already checked with the gas company, no issues there). The display membrane says service heater. The circuit board on the underside has AFS and LED11 lit. All of the visible wires look good & secure. I do not see any blockage for the blower & air flow. The gas valve is switched to on. The AFS light goes out when I give a easy blow into intake side tube (but nothing else happens). The heater temp is set to high 90s (water is currently in the low 80s).


The heater is controlled by a pentair easytouch control system. The heater is almost 5 years old. The only thing fixed/replaced on it (about 2 years ago) is the display membrane.

Any help would be appreciated.

 

[borjis]

might try to remove the panel and inspect the burner tray & ignitor area for spider webs.

 

[Poolbreh]

If the blower isn’t coming on you will need to run through the troubleshooting.

It could be a loose connection after changing out membrane. Or it could be something more serious.

 

[1poolman1]

might try to remove the panel and inspect the burner tray & ignitor area for spider webs.

Master Temp = sealed combustion chamber.

 

[ajw22]

The blower needs to begin running and the air flow switch needs to sense proper air flow before anything happens with the ignition sequence.

Various information about testing the air blower is in Pentair MasterTemp Heaters - Further Reading

Check the insides carefully for any signs of rodents in the heater. They like nesting in the air blower area.

 

[ps0303]

Bad blower motor or bad run start capacitor if so equipped.

Post a picture of the motor.

 

[Cabby]

I have to remove my heater in the Intellicenter interface and re-create it to get it to fire up on occasion.

 

[miller351]

Bad blower motor or bad run start capacitor if so equipped.

Post a picture of the motor.

I took off the back piece of the motor and all looks good from what I saw so far. This flat head screw must be connected to the blower fan itself because when I turn it, it spins freely with no obvious issues.

 

[miller351]

might try to remove the panel and inspect the burner tray & ignitor area for spider webs.

Sorry, but can you be more specific as to where the burner tray & ignitor is for a Mastertemp 400?

 

[miller351]

I have to remove my heater in the Intellicenter interface and re-create it to get it to fire up on occasion.

Thank you for the tip, I will try that.

 

[miller351]

As I was poking around, I saw a solid red light on this Igniter Control module. Could this be the root cause?

 

[borjis]

Sorry, but can you be more specific as to where the burner tray & ignitor is for a Mastertemp 400?

My error. It doesn't have that ability.

 

[miller351]

Update: the issue is resolved.

As soon as I replaced the Igniter Control Module, the heater fired right up.