Pentair Minimax NT Error E04

FLSTF · May 29, 2015

Hi everyone. First post here. I have a Pentair Minimax NT 200 that is giving me fits. Late last season the fan started making noises and I started getting the E04 error. The fan was obviously bad so I replaced it. It worked most of the time, but I would get the occasional E04 error, which I thought was do to a bad seal that I put on when installing the new fan. I resealed everything this year and it worked when I first started it up, but now the E04 is back. When it turns on, the fan starts, then after 20-30 seconds it calls for gas but the gas doesn't light and it shuts off the gas. It does this a few times then the E04 comes back. I know it's getting gas because I can smell it but it won't ignite. I checked the tube from the blower to the flow switch and it's clear, and I cleaned out both connections. Now I figured it must be the igniter, so I replaced that. Still nothing. It's doing the same thing, fan turns on, calls for gas and no ignition, shuts off the gas and cycles through again.

I'm at my wits end. Any suggestions would be greatly appreciated.

cit1991 · May 29, 2015

It wouldn't try the gas if it didn't have a pressure signal from the sensor indicating fan operation.

If you have gas (by smell) and no ignition, then all it should need is for the ignitor to work. I had a problem like this once (gas on, smell, no ignition) and it was the gas shutoff valve on the gas line coming in. Yard guys had knocked the handle almost closed...almost. Fully opened it again and it worked fine. Check your gas supply. These things use a lot of gas and the lines can't be restricted.

Good luck.

ps0303 · May 30, 2015

So can you see the ignitor glowing when it tries to light?

FLSTF · May 31, 2015

No I don't see it glow but I checked and there is power going to the igniter. Could the new igniter be bad?

ps0303 · May 31, 2015

If you have power for sure going to the igniter but it doesn't glow, replace igniter.

FLSTF · May 31, 2015

It's a brand new igniter that I just installed.

ps0303 · May 31, 2015

OK. Where are you checking the voltage going to the igniter and what are you getting? If you have voltage going to the igniter but it's not glowing, then it must be dropping out. Set your volt meter up and disconnect the igniter, put a lead on each connector of the igniter wire where the igniter plugs in and then turn heater on. You should see the correct voltage and for about a minute or so when it calls for the igniter to glow. If it's just a very short momentary of voltage, then you might have a bad control module. If you aren't seeing any voltage, bad control module as well more than likely.

You could also have a bad control module that is causing the igniter to go bad. So instead of the 120 you are seeing 240 being sent to it.