Max-e-therm not firing

[swedejr]

First post here… my Max-e-therm heater isn’t firing when I go to put it on. Control board is relatively new. Probably replace a year or two ago.
I put “spa” function on, shows temp, “heating “ led flashes for about 30 seconds, and then the “Service Heater “ comes on.
Fenwal box shows 1 flash omits led, meaning no air flow. Jumpered out F1 and F2 and fan comes on. So I know the fan is good.
I tried jumpering out pressure switch and air flow switch.
Any ideas? Bad control board? Bad Fenwal?

Thanks in advance!

 

[1poolman1]

First post here… my Max-e-therm heater isn’t firing when I go to put it on. Control board is relatively new. Probably replace a year or two ago.
I put “spa” function on, shows temp, “heating “ led flashes for about 30 seconds, and then the “Service Heater “ comes on.
Fenwal box shows 1 flash omits led, meaning no air flow. Jumpered out F1 and F2 and fan comes on. So I know the fan is good.
I tried jumpering out pressure switch and air flow switch.
Any ideas? Bad control board? Bad Fenwal?

Thanks in advance!

During the try for ignition, does the fan turn on?

 

[swedejr]

No. I get nothing. I jumped out the fan, and it will spin. Nothing on startup

 

[swedejr]

”Heating” led will come on for a few seconds, then “service heater” comes on

 

[1poolman1]

”Heating” led will come on for a few seconds, then “service heater” comes on

Here's a troubleshooting guide attached.

 

[swedejr]

Thanks Poolman! I’ll try to troubleshoot tomorrow morning.

 

[swedejr]

So… the Fenwal unit was bad. Installed that, and found the igniter was a no go. In trying to remove that, it came out in pieces due to a ton of corrosion.
Looks like I’m in for a new heater. No sense throwing good money after bad.