Pentair Master Temp 400, completely dead


LifeTime Supporter
Feb 26, 2012
Lancaster, PA
He folks,

Master Temp 400, was working great, one evening a few days ago I noticed that once it reached its temp, it would not restart to maintain the temp. This has happened a few times last year, but I reset the heater and things where fine. That nite I went to look at the heater and notice water leaking , and determined the The Pressure Relief Valve (TecMark 4037P-cwcw) had rusted and was gushing water. so I shut down the entire system and order a new PRV. I installed the new valve, no leaks, Great. went to turn the heater on and NOTHING.

to lights, no Nothing, completely dead, check power going to it, yeap had power.. and then I noticed this sound, swirling water sound near the manifold and pool return portion of the heater, sounds like there is air or something loose, is the sound related to the heater being dead ?

can anyone advice on what to check to get the heater up and running

I have a video, but can't figure out how to attach

Any Help would be great.
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