Pentair Minimax NT STD ERR message

Chucky · Postby **Chucky** » Mon 04 Jun, 2007 01:28

Pool Wiz:

I have a 2003 Pentair Minimax NT STD 400,000 BTU heater. I've had a lot of construction going on in the backyard over the last few years and have turned the gas and electrical off many times. The heater has barely been used and just recently it came up with an ERR message. I have looked over the heater, cleaned it free of debri and have powered off and on to reset the unit. The ERR message is still present. Do you have any suggestions as to what part may be faulty and are there any common problems with Minimax NT in general. Thanks for your support.

Walter · Postby **Walter** » Mon 04 Jun, 2007 10:23

Sounds like you need to contact a pool service company to look at it, their could be just about anything wrong with it. Good Luck

howzball · Postby **howzball** » Mon 11 Jun, 2007 15:41

Chucky wrote:Pool Wiz:
Do you have any suggestions as to what part may be faulty and are there any common problems with Minimax NT in general. Thanks for your support.

If it's anything like the Pentair MiniMax NT we had, the best advice is to wrap a chain around it and drag it to the curb. I'll never buy another Pentair Heater!

This unit was in service for exactly one year and when it was removed, it looked like a 30 year old unit. It was that burned out and sooted up.

After numerous errors and several trips out by their service rep. they now tell us that the Minimax NT was just a stopgap fix for a LowNox system at the time and they have now stopped making them.

They replaced our unit with a 200,000 btu Peerless unit that oddly, resembles R2D2 or a shop vac but it's working perfectly so far.

I was impressed to learn that a 200,000 BTU unit on a 50,000 gallon pool keeps up perfectly, 90 degrees F. all the time.

Guest · Postby **Guest** » Sun 08 Jul, 2007 00:14

i have the same err message on my unit. i have checked everything and all connections are solid. i have tried turning power off and back on. what do you recommend beside calling mfg. thanks

Guest · Postby **Guest** » Thu 12 Jul, 2007 18:12

I have a mini max 250 btu that iv'e had nothing but problems with. My latest problem is the temp reads 110-114 deg no matter what i do

James · Postby **James** » Fri 13 Jul, 2007 13:00

Our MiniMax NT 250K BTU had the same problem - except the cabinet was completely rusted out. It looks like it has been there for 30 years, and it looked like that after only 1 to 1.5 years of service. Pentair wouldn't cover any repairs or replacement even though the unit was still well under warranty.

The new MasterTemp series from Pentair is much better in terms of design, I think, since most of the unit is plastic. I hope that doesn't turn out to be a problem, but since my biggest problem with the MiniMax NT was corrosion, I am happy not to see steel all over the place.

A word of warning - I purchased the heater from an online store, who was in coordination with Pentair during the purchase. After receiving the pool (the following day!!!), I started calling local companies about installation. They are all basically pissy that I didn't purchase the heater from them, and several have basically said "we're not touching it because it probably doesn't have any warranty".

I do finally have an authorized Pentair service company coming next week to do the installation.

Pentair just bought Sta-Rite, so unfortunately, we're running out of choices.

Backglass · Postby **Backglass** » Fri 13 Jul, 2007 13:12

Heat pumps have a flow sensor so they don't kick on when the pump isn't running. Perhaps it is bad and thinks there is no flow?

SteveM · Postby **SteveM** » Fri 30 May, 2008 19:00

Anonymous wrote:I have a mini max 250 btu that iv'e had nothing but problems with. My latest problem is the temp reads 110-114 deg no matter what i do

did you find fault with high readings? Mine does same.

Travlnwood · Postby **Travlnwood** » Fri 28 Nov, 2008 16:58

I agree 100% with Chucky. Wrap a chain around your minimax NOW before you spend anymore money on it and drag it to the curb! EACH and EVERY time I have tried to heat my pool or spa with this unit since purchasing it in 2005 it has cost me another $500 in repairs. It's a lemon. Has anyone had any satisfaction from the manufacturer?

96fatboy · Postby **96fatboy** » Mon 08 Dec, 2008 10:33

The NT heaters will give an ERR message when the thermistor is bad or voltage to the back of the control board drops below 20vac. 9 times out of 10 it is the thermistor or temp sensor. A soot build up would lead me to believe there was an issue with either gas pressure or gas flow. With the heater fired the pressure into the valve should maintain no less than 6" wc for natural gas 13" for propane. If the pressure is good, it is a good idea to clean the orfices regularly to ensure good gas flow to the burners.

Pentair Minimax NT · Postby **Pentair Minimax NT** » Tue 21 Apr, 2009 14:10

It is unanimous. The minimax NT is a loser. Won't buy pentair ever again. I have had a few consecutive weeks of use, but my repair man is sending his kid to Ivy League now.

rastare1a · Postby **rastare1a** » Sun 14 Feb, 2010 17:18

I had to remove and clean an electronic chlorinator attached to my system. When I restarted the system, the MinimaxNT started giving an ERR message and the service light is on. Besides calling a technician is there anything that I can try on my own to get the Err message off? Cycling the power as suggested in the manual did not work.

Thanks in adavance

Guru · Postby **Guru** » Thu 18 Feb, 2010 14:40

9 times out of 10 the "ERR" code is caused by a bad thermistor (temp sensor). This can very easily be checked. Simply open the front door and look directly behind the control board. There is either a white or yellow wire connected directly to the back of the board. Make sure heater is off, then unplug wire and turn on. If this was the problem, the "ERR" should be replaced by 3 dashes: need new temp sensor. If it STILL is getting the "ERR", it's the control board itself: 2 knobs= 6800 controller, digital= "DDTC" board. Hope this helps. Alot of people don't like the NT but it IS a higher end piece of equipment.

rastare1a · Postby **rastare1a** » Tue 23 Feb, 2010 19:31

Hey Guru,

Thank you so much for the advice and the tips. I will keep your response for future reference. As it stands, I ignored the ERR message once I determined water was still flowing through the system. I checked the system two or three times and the ERR message was still displayed. Today however during it's usual run-time the temperature was once again displayed on the LED readout. I don't know why or how it recovered, but for now I guess that will do. I haven't tried to turn the heater on yet, but will update the forum if there is a problem.

Thanks again..

andreyayrapetov · Postby **andreyayrapetov** » Fri 28 May, 2010 14:32

I had a flood the other day by my pool equipment while the filter pump was running. The pump zapped and broke. I replaced the pump and now the Heater is showing Err code. I called Pentair. The tech had me check the thermistor and that was fine. He said it's probably my DDTC board. Before I spend $250+ I wanted to know if there was a way to test that or any other suggestions. Thanks in advance.