Sta Rite MaxiTherm "Service System" PS LED on

[davilito]

My maxitherm heater wont fire. the service system light is on. The PS LED (under the display panel) is on. I checked the pressure switch and it is not malfunctioning. Even jumped it and system still wont fire up.
Thoughts?
Thanks.

 

[ps0303]

So you shut off the heaters power, jumped the pressure switch, and turned unit back on and what happened? Did the PS light go out or stay lit?

 

[davilito]

Yes. Powered down, disconnected power (I have it on a switch), removed the leads going do the PS and jumped them with a jumper lead I made to close the circuit. When I powered up and started the heater, there was no change. Only the service system light is on on the top of the panel and the PS LED is still on under the panel.

Thanks for your help.

D

 

[danpik]

It is possible that the board is looking for the switch to be open prior to starting. This is something that was added a few years ago to prevent the switches from being "permanently" disabled. Check the vacuum port to be sure there is no obstruction blocking the flow.

 

[ps0303]

I'm saying the control board has an issue. You can still jump out a pressure switch on these units before they try to start. The air switch is a different story as you have to wait a few seconds before you jump it out once the system tries to start up.

 

[danpik]

I'm saying the control board has an issue. You can still jump out a pressure switch on these units before they try to start. The air switch is a different story as you have to wait a few seconds before you jump it out once the system tries to start up.

My bad. I was thinking the vacuum switch not the pressure/flow switch.

 

[davilito]

Do you mean the control board under the display or the brain inside the enclosure in the unit?

 

[ps0303]

Under the dome where you saw the PS light, that is the board I am talking about. The display is part of it.

 

[Pool Clown]

Visually inspect the wires all the way that run from the pressure switch to the board. Just to be sure they have not been chewed.

 

[chefaustin]

Visually inspect the wires all the way that run from the pressure switch to the board. Just to be sure they have not been chewed.

I ran into a situation last year where I was getting an AFS LED. Wasted money on a new air flow switch only to still find the heater not firing up. Ultimately ended up pulling the blower motor out to find several dead mice and other debris down in the flame holder that was restricting the flow of air through the system. Cleaned it up and resolved the problem.