20 Most Recent Pentair Minimax NT Heater - Page 9 Questions & Answers

sometimes the door is just stuck. try pulling the door as you turn the locking screw. sometimes you need to use a flat head screw driver to help the door open as you turn the screw back and forth

check the manual or go online if you don't have one. each error code will have a description of possible problem

Is there any lights on? If there are and still no error code, just blinking lights. Check the thermistor. I had a similar problem. Heater had power, lights were on SW was green but no error code and would not fire up. I replaced the thermistor. It took me all of 5 minutes and heater fired up and is working great.

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First you will need to get a hold of a digital or analog multimeter and set it for the lowest range of Ohms you can. Your safety circuit is a string of several switches all strung together in a row with the gas valve at the end and the beginning of said string. Any one switch being open or a bad connection anywhere in the circuit and the heater will not fire. You task is to remove one end of the circuit from the valves TH or TT post and put one end of you meter on that wire and the other end on the TH/PP terminal. It will likely read infinite resistance. Leave one meter lead where it is and remove the other. Follow the circuit from the connected lead up to the first switch. Check continuity from the lead left connected to both sides of the switch. If there is continuity to both sides the switch is fine. Keep moving from switch to switch until you find the bad switch or connection. There may be more than one. When the circuit is working properly and there is nothing within the heater to cause it to shut off you should have 5 ohms or less across the entire circuit. Once you get the reading to that level the heater will work as it should If you are not familiar with the process I described you would be better served hiring a pool technician to perform this repair as you can cause significant damage to the heater if you do not repair it properly.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

IMPORTANT! IT IS RECOMMENDED THAT NO MORE THAN TWO IGNITION ATTEMPTS IN SUCCESSION BE PERFORMED FOR NATURAL GAS SYSTEMS . BEFORE FURTHER IGNITION
ATTEMPTS, WAIT AT LEAST FIVE MINUTES FOR GAS TO CLEAR.

1. Should the main burner fail to light, or flame is not detected during the trial for ignition period the
control will go into lockout and the valve will be turned off immediately.
2. Recovery from lockout requires a manual reset by resetting the thermostat or turning off the ON/OFF switch for a minimum period of 5 seconds.

If the heater continues to go into Ignition Lockout mode:
The ignition control box will spark the pilot and detect that it is lit. These boxes are very reliable but they can fail. I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

Replace your flame sensor

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Couple of possibilities:

1) There is not enough system pressure to close the heaters pressure switch so the heater will not fire.

2) The pressure switch is damaged or has failed.

3) Poor flow from a frozen line.

Assuming your pump is on and any valves in your pipes are set correctly is there decent return pressure back to the pool? If so it is not a freeze issue.

The first place to start then would be the baskets and filter. Start at the skimmer(s) baskets and then the pump strainer basket and finally clean your filter. If it’s a sand filter backwash it. If it’s a cartridge or DE filter, clean it according to your manufacturer’s direction. In some cases cleaning a cartridge filter will no longer satisfy heater pressure requirements meaning you will need to replace the element.

If you are able, you can check for continuity across your pressure switch with the heater off but the pump turned on to be sure it is operating correctly.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

HI is a code for Water temp over 114. If this is what you have the temp sensor has gone bad. Or thermister. It will be a small tube that slides into the water manifold with two wires coming from it. A white nut sets it in place unscrew this pull out follow the wires to unplug then slip the new one in.

It is also possible that you have enough water flow to close the pressure switch circuit, but not enough to keep the water from getting to 114 F by the time it reaches the temp sensor.

Also, the bypass valve might just need an adjustment . If its bypassing too much water, you will get this code as well.

Hope these ideas help

if you have ignition and you know that the flame sensor is good, it is either a wiring problem or the ignition module.
Note: Ive installed brand new flame sensors that were defective. Took me days to figure it out since id just replaced it.

Yes there is, but only a service technician is allowed to adjust it. However, the fact that you are only reaching 78 degrees makes me think something else is wrong.

Your bypass valve is probably the culprit. It is located where the Pipes enter the heater. It has a spring on it that is thermally activated to open and close. This allows the right amount of water to pass through the heater. Too much water and the water will not heat up. Too little water and the heater will vibrate and howl!

You could also have a faulty thermostat.

Also, always use a heater blanket when trying to heat a spa or pool. It will save you lots of money and time! And they are cheap!

Depends on how you turn it on: At the heater itself or with an automation system. If its with an automation system than your problem is with it. I assume this is the case.

When you turn the spa off make sure you turn the heater off first and then wait a few minutes before turning off the spa pump.

Also, check your programming.

Unscrew the 5 screws holding in the restrictor plate. then unscrew the 2 screws holding the sensor. Then clean it. Then reverse.

FYI flame sensor is the part on the bottom inside the cabinet next to the ignitor. It will have one wire only

R5 is a revision number

You may have a bad board or bad keypad bezel. Try using the other thermostat button. Either Pool or Spa button should activate the unit.

You might try pulling the tray and see what the burners look like. If you have a manule you can follow the directions on turning the heat exchanger around and it will tell you how to pull the exchanger without hurting anything. Once you get it out you can pull the header and see if you have any build up inside it. If you have access to a manometer you should check your gas pressures into and out of the gas valve and be sure their OK.
Before you buy a control module it would be worth while to have a repairman out to check it out.
Hope this helps.

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Splice the two wires together and try to fire the heater. MAKE SURE THE PUMP IS ON when trying this to avoid any possible damage to the heater. Once you confirm the unit works with the pressure switch bypassed put the wires back until the new part arrives. DO NOT operate the heater with a jumped pressure switch as any disruption to water flow can create a very serious danger to anyone or anything near the heater.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!

John

First of all, if your service tech cant diagnose your heater, its time for a new technician. There are a multitude of possibilities that could cause your heater to operate this way. To try to help you though Id need more information. Please contact me @ [email protected] if you wish me to walk you through some troubleshooting procedures. Also below you will find 2 links. The top link is to Pentairs service center locator. Just search in your area, and it will list reputable companies approved for working on this heater. The second link is a link to the SERVICE manual for this heater. It is not a users manual that would come with the heater, it is a step by step instructional on how to troubleshoot every aspect of the heater. This is the first thing your tech should have gotten BEFORE servicing this heater.


http://www.pentairpartners.com/dealerlocator/dealerlocatorlist.aspx
http://www.pentairpool.com/pdfs/MiniMaxNTServiceManual.pdf

Troubleshooting starts on page 35

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Hi means the unit believes the water is 114 degrees or higher. The problem, assuming the water is really not that warm, is the thermistor in the header. You need to replace it with a new one as its function is to read water temp and feed that info back to the control board. It is a part most people can replace on their own.

Your part number should be: 471566

If this answer does not fix your problem, please comment with additional details prior to rating the answer. You may also contact me thru our website at www.arrowpools.net. Positive feedback is appreciated once your problem is solved!

John

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That unit will not fire until you resolve the pressure switch issue; either the flow is reduced to low and the pump/filter system needs to be thoroughly cleaned or the switch or control board has failed and need to be repaired.

Start with a cleaning of all baskets and filter to see if the light clears and the heater works; if not look at replacing the pressure switch. It is not uncommon for the switches to fail but check it with a meter set to ohms if you can. Power off the heater first and pull one of the wire leads off. Put the probes on the terminals with the pump running and see if you have a circuit. If not, replace it. If the switch tests fine the problem is in the control board and it will need to be replaced.

If this answer does not fix your problem, please comment with additional details prior to rating the answer. You may also contact me thru our website at www.arrowpools.net. Positive feedback is appreciated once your problem is solved!

John