HeatMaster 400 stack flue sensor replacement

Jun 3, 2012
Hi folks. the heatmaster 400 threw an e05 error. heater turns on for 15 seconds and then turns off. all research shows that it is a bad sensor.

The question: Is there a difference in longevity in the Pentair 42002-0024S vs the non Pentair stack flue sensors? Pentair brand is upwards of $70+, non Pentair replacements are $22 on Amazon. Is there a difference? Thanks.



TFP Expert
In The Industry
Jul 6, 2011
You get what you pay for in most cases. Although it might be more expensive, the real deal Pentair part should be the way to go. I have no clue who makes the knock offs or if they are reliable. I guess the worst that could happen is the knock off fails and the heater melts down.