Pentair Minmax Plus 400 Pool Heater Issue

Jump to latest Follow Reply
R

rkongjm

0
Jul 2, 2011
4
I'm wondering if anyone has run into this problem...

I have a 11 year old Purex Minmax Plus 400 Pool Heater which is cycling on and off. Here are the symptoms

When turning on the heater it will run for a few minutes normally and then shut off with the service light on. When this occurs I hear a clicking noise coming from controller module (not the igniter). If I turn off the heater for a short period of time (10 mins) and then turn it back on. The heater runs for a bit and then shuts off again with the clicking noise. This almost seems as if there is some sort of thermal / overheating issue occurring.

If I do not turn off the heater, the igniter in the unit remains hot and the unit does not turn back on. It is only when I shut the heater off for a short period of time that I can get it to restart and run again for a little bit.

This is what I have done so far...

1) I have backwashed the DE filter and also place the filter in recirculate mode. Same problem occurs
2) I have replaced the control module. The problem still occurs.
3) I have tried cleaning out burners by blowing compressed air through them. Still the same issue

Does anyone have any thoughts on anything else that I can check or do?

Thanks in advance!!!
Bob
 
When this problem occurs the following status lights are lit

TSTAT - On
Aux - On
Pressure - On
Heat - Off

Power - On
Service - On

From the Minmax Plus Owner's Manual that I found online states that the issue is the TFuse. However, looking at the TFuse it looks ok, and I would think that it blew due to over heating that it would remain off.

I did do another test, where I moved the TFuse from inside the unit to outside the unit (leaving the access panel off) and the problem still occurred.
 
A bit more information... I did some more testing and tinkering with heater and I think I have come to the conclusion that it may need to be completely replaced.

With the front cover off exposing the burners, I fired up the heater. As expected it ran for about 5 to 10 mins and then shut off. However, this time I noticed some sizzling sounds coming from the heater. On closer inspection I saw that there was some water that would drip onto the burner. When the water dripped onto the pilot/igniter it would put it out, thus shutting the heater down and preventing it from restarting until it was dry again.

So this looks like the manifold on the inside of the unit has a leak, either corroded, cracked, or broken seal. When heater is not running there are no leaks, no drips, or water wet spots underneath the heater. It only seems to occur when the heater is on. So it is making me believe that the leak is caused due to expansion of the manifold (due to heat) or increased pressure in the heater (due to heat).

Right now I am not sure if want to attempt to take apart the heater to replace the manifold or just replace the entire heater since it is now 11 years old.
 
If the water is cold, the dripping you are seeing while fired is likely condensation. Typically the pilot lights have a drip shield to protect them from getting put out, but often times the drip shield corrode and disappear.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply