Pentair Minimax NT Problems?

Electric heaters, gas heaters, heat pumps,
solar heaters, geothermal heating, solar pool
covers and wood-burning pool heating equipment.

Pentair Minimax NT Problems?

Postby papoolservice » Fri 09 Jul, 2010 10:35

I've been working on heaters for 20 years. the nt tsi - as well as most electronic heaters - but this pentair being the worst - IS JUNK. Every one I've installed I was back replacing flame sensors and blowers within a year. As far as the HSI, just trying getting one shipped! I had three broken in shipping before I got one that was in one piece. Installing or removing them is a surgical procedure as they are more fragile than glass. If you have condensation building up on one you may have an insulation problem.

i am fighting with one AS WE SPEAK and have replaced the valve, the blower, vac sensor, flame sensor, fenwal control, and tested both incoming and differential pressures with no problems. However, E04's and E05's continue to pop up, and this thing is an hour away from me.

My advice - if you REALLY want something that's easy to diagnose, stick with MV, and if you do commercial work, Raypak DOES make an ASME header in MV. Raypak is a bit more expensive but worth it - it's all they do - and they have taken strides to make them easier to work on, based on service tech complaints such as mine. Apparently hayward is getting into ASME this year but they're all electronic.

Putting electronic controls in units that are burning in the hundreds of degrees is just bad practice...the sensors and controllers should be located somewhere outside of the heater, then maybe you'd have something. The blowers burn up fast - especially if the heater is used alot. I have a 250kbtu on a condo pool, 19000 gallons, no cover, and they want the temp at 88 constantly. The heater burns constantly and they don't want to hear that there are cheap parts in their heater. they think I'm putting garbage into the heater - it's all OEM parts, they're junk. Let the customer fight with it for a few years and then talk them into a good price on a millivolt. Install a relay and put a power vent inline in the stack. You'll accomplish the same thing and be able to troubleshoot it in 5 minutes or less every call you get.

recycle the heat exchanger and use that money to lower the customers price for the new heater. you'll save two headaches.


Pentair Minimax NT Problems?

Postby Artman1 » Sun 18 Jul, 2010 22:06

pool baby wrote:I have a Minimax Nt gas heater. The technician put a new heating element on it because it stopped heating. Stated it was fixed . Now when I turn it on the heat light comes on for about 10 seconds and the blower then it shuts it's self off. Any suggestions?

I had a very similar problem with mine. I replaced the flame sensor (about $17) and all's okay now.

Pentair Minimax NT Problems?

Postby mdrdpchc » Tue 20 Jul, 2010 20:39

how can fix e04---fan failure.

Pentair Minimax NT Problems?

Postby hmiller-2010 » Tue 27 Jul, 2010 06:37

:shock: Call and get tech support.

Pentair Minimax NT Problems?

Postby poolandspaguy59 » Mon 12 Sep, 2011 17:07

I have had nothing but bad with this heater. very expensive to fix. problem after problem. if you have nothing better to do and alot of money. but one. i only bought one but paid for 2 in as little as 4 years and i dont charge myself labor. no joke they suck...

Pentair Minimax NT Problem -

Postby Indi » Thu 20 Oct, 2011 21:01

My Minimax NT isn't working - When I checked it out, I smelled gas so I turned off the pilot, then turned it back on, only to smell gas again (now it's off). Also, I noticed water seepage on the sheet metal on the bottom of the heater and on the ground below and around the heater. Could these be related?

Pentair Minimax NT Problems?

Postby Icanfixanything » Tue 15 Nov, 2011 20:18

jcombs wrote:I have the Mini Max NT Nat Gas 400 and I have replaced the blower motor assembly twice in 5 years because it rusted. It has a rubber ture on the side that goes to a vacum switch, I an not getting sucton from the blower assembly to the tube can anyone tell me if the suction out of the barb is strong enough to feel?

Next time instead of replacing the entire blower, you can easily replace the blower wheel as it is common that it rusts and falls apart. The part # is Fasco 1-6143. Cost $27 and fixed it in about 20 minutes.

Pentair Minimax NT Problems?

Postby Leonking » Wed 30 Nov, 2011 21:30

My heater is showing An eo4 problem. The heater was wrking fine all summer and mysteriously stoped heating. Had a tech come out to look at it and within 10 min said it was a bad fan. That he could not diagnose it any future without that fixed first. He then said that the price for the fan is 550 to 650 dollars. I had to send him away for now. Is he rt? Any help would be appreciated.
Not a heater repair guy

Pentair Minimax NT Problems?

Postby Not a heater repair guy » Fri 02 Dec, 2011 09:54

I'll give everyone having weird intermittent behavior with their Pentair Minmax heater a hint up front, before the long story below. REPLACE THE RUN CAPACITOR ON THE FAN MOTOR! It is a $10 to $20 part that can be replaced in 15 minutes. Just waste $20 and do it first and see if it fixes all your problems.

Turn off breakers, confirm no power to unit, remove 6 screws on top that hold the fan cover down, pull the cover up and off, and remove and replace the oval run capacitor. You need a 5MFD, 370 V or greater oval capacitor, available on the internet or most HVAC supply stores.

E04, EO5, fan eventually not running, ignitor module flashing once, twice, control panel eventual not powering up were all caused by the capacitor slowly degrading and taking out the AC transformer and low voltage power to the ignition module and DDTC controller board.

The next post gets the long story.....
Not a heater repair guy

Pentair Minimax NT Problems?

Postby Not a heater repair guy » Fri 02 Dec, 2011 10:31

Long version of the previous post, read the post before this for the short version if you are getting E04, E05, reseting panel, all with fan apparently running fine. A $10 part might fix all your problems!

I'm an engineer, I like fixing things. I have a pentair minimax, about 7 years old. Worked fine except after about 3 years, it would throw and E04 right after a big rain storm. By the time things dried out and I got out to fix it, it would clear.

About a month ago, heavy rain, EO4, more persistant than before. Sometimes run, but mostly E04. Plenty of time to fix it this time. Fan is running; must be the fan switch. I replace it; E04 with fan running. Check the hose, clear the hole into the fan; E04 with fan running. Look at the motor housing, what a crappy job they did sealing it up with goop, maybe it is leaking. Go to the autoparts store to get some high temp RTV (it is hot down there), seal it up real good; EO4 with motor running!

I decide to simulate the proper operation of the fan switch with a wire (leave terminals open until I hear the fan, then short them with a wire). Heater starts! WTF? Repeat this a few times, once out of ten times the fan fail light comes up on the ignitor, one other time it flashes twice (no heat after ignition) but mostly starts. WTF?

After the 10th time, the entire panel goes blank, won't come up. Check the AC transformer that powers up the panel. No output. Transformer blown? WTF? Was the transformer feeding flakey power the the modules and make them act weird?

Order a transformer on the internet for $40 including shipping (local price $60 to $160, and I had to wait 3 days and then go back and pick it up when it came in). Easy install, except one mounting hole was off and had to open it up with a drill. Power up and voila, panel lights up. Turn it on and whish, heater starts up.
I go off and crack open my beer, come back, and the unit is shut off! WTF?

Turn it on, and fan doesn't start. WTF? Power is going to the fan, but not running. Touch the motor housing and almost burn myself. Touch the run cap, crap really hot. Remove it, do the capacitor test with multimeter (look it up on the internet, short the cap first for safety) and it tests bad. Order a cap on the internet beacuse it is midweek, and HVAC places only like to open between 10:00 and 3:00 on weekdays.

Get the cap, install it in 15 minutes, power up. Whoosh fires right up!. Turn off, power up 3 for 3. Let it run, cycles, works GREAT!

The sequence of most likely events was that the run cap slowly degraded, and was throwing all kinds of electrical spikes back into the input power. The messed up input power feed through the step down transformer, corrupting the power to the ignitor and DDTC controller, causing wierd behavior at first, then eventually blowing the input transformer itself. The cap then degraded to the point that the motor wouldn't even run. Thnak god it finally completely died and pointed me to the root cause of all my problems!

Let everyone know if this fixes your problem, or if it was just my bad luck. I have a feeling a lot of bad motors, ignitors, and other problems are just due to a $10 cap wearing out....

Return to “Solar & Pool Heaters”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests