20 Most Recent Pentair Minimax Ch 400,000 Btu Propane Pool Heater Millivolt Ignition Questions & Answers

check gas pressure and supply line could be running out if ok when shuts down check voltage at transformer

It will not work more than a few minuets. The small tank will not contain enough volume required for the liquid propane to boil off the amount of vapor you need to feed the heater. In fact you are more likely to damage the heater if it does run because it will be a very lean burn.

Cleaning the Thermal couple can work at times, however most times you will need to replace it. You may also be having an issue with the ignition control. You are in pretty deep now and it would seem like you are determined to save this heater, I would change them both. http://www.parts4heating.com/Pool-Heaters-Pentair-MiniMax-NT-400-s/696.htm

I am not sure if you have solved this issue, or not, but just in case.

If the tablets are not dissolving, there are two possible reasons. The first is that older tablets do not dissolve that well and if this is the issue, but new ones.

The second is that the 320 has a small screen at the bottom of the tubing. This can become clogged, or some the the tubing, and will need to be cleaned. The best thing to clean the parts on the 320, or other In-Line Feeders, is NON-ACETONE FINGER NAIL POLISH REMOVER. Make sure you use the NON-ACETONE kind since Acetone can melt the plastic parts!

You just need to soak them in the polish remover and rinse. If scrubbing is needed do so with a soft cloth, tooth brush or other non-abrasive material. For a parts breakdown and manual on the feeder, please follow the link below.

http://www.pentairpool.com/pdfs/320Chlorine-BromineFeeder_UG.pdf

Possible bad water temperature sensor.

You have a bad igniter. What is the model number on the unit?

A lot of people are have trouble getting their pool heaters to work after sitting for a long time. And one common complaint is that the pilot light will lite, but then the burners won't fire up. We have found that like a lot of furnaces the thermocoupler will corrode rather quickly when not constantly used, i.e. pilot light lite. Most of the time the problem can be rectified just by cleaning the thermocoupler with either steel wool or a green scouring pad. This takes off the corrosion which allows the thermocoupler to be heated by the pilot light, which will then allow the gas valve to open to provide gas to the main burners.

Once you do get the main burners activated, take a look at your flames. If they are burning blue primarily then the system it operating to peak performance but if there is more yellow than blue, it is usually a sign that your burners have become dirty or corroded and you need to clean them for peak performance. A good medium stiff brush and a good vacuum should help with that. Just don't try for perfection and scub to hard.

If the unit has milli volt gas system, make sure that the thermopile is properly heated by the pilot flame so that it can generate 500 to 759 milli volt to fire up the main burners. Check the thermostat board if the relay contacts on th/pp and pp closes as the potentiometer is increased. Milli volt that will energize the main valve of the gas valve passes through this contact and also on thermal cut off fuse, pressure switch, safety shut off and hi limit, make also sure that the contacts of these components are closed or having continuity across the terminals when tested with an ohm meter.
For your reference, you can download owner's manual complete with wiring diagram, parts list and troubleshooting guide for different models at http://www.pentairpool.com/pdfs/MiniMaxCHOM.pdf
Regards.

British thermal unit: a unit of heat equal to the amount of heat required to raise one pound of water one degree Fahrenheit at one atmosphere pressure; equivalent to 251.997 calories. The amount of heat needed to raise 1 pound of water 1 degree F (equal to 252 calories).
(British thermal unit) Describes the heat value of fuel for appliances - the higher the BTU, the more heat available for cooking.
A Btu is equivalent to 252 calories and serves as the base unit for measuring the heat content of a fuel source.

-The Ugly Pool Guy www.wefixuglypools.com

If you have a pilot their will be a flame sensor that's part of it. If this is a glow plug start it will be a probe that goes through the fire wall and is just above the burners. When you get flame the electrons align so that you will get a signal back at the ignition control that will let teg heater run. If it dosn't get a signal it shuts down so you don't get a build up of gas. Then it reset's and tries again. What your describing is a bad sensor or wire. Could be carbon build up on the sensor. If you can't find any problems with these you may have a bad ignition control box. First I would check the wire, connectors and probe itself.

Pull the lower front panel and inspect the top of the burner. If there are ashes and debris on top of the burner, especially near the ignitor, then clean it off.

First have you always had this connected to propane? There are different models for natural gas and for propane.If you connect a natural gas to propane the "jets" are way too big for propane. How did you clean the jets? IF you "drilled" them out they may be too large now. If you have adjusted the gas regulator, decrease gas pressure. I believe this unit has a combustion blower, be sure it is debris free on inlet and in fan, check for leaves. Make sure black smoke is not coming from debris built up inside of heater. Here is a link to a location for the complete manual for your heater: http://lawnandgarden.manualsonline.com/manuals/mfg/pentair_pool_products/400k_btu_hr.html

Any pool store or a hardware store. It is just a 2 pound pre. sw. Take it with to be sure the threads on the bottom match up. You can probally get a universal that will come with assorted adaptors. First be sure you dont have a plug at the hole it goes into. Be sure that your baskets are clean and your filter is clean and their is nothing clogging your impeller. These are the things that a pressure switch guards against. If it is one of those things then it is just doing it's job and a new one will do the same thing. Good luck.

Maybe these two links will help you... Good luck!!! Link one and link two