Condensate switch failures (Posting here because you folks use these pumps a lot)

Diversitech

Although I have never used that exact model I have two of their floatless cube units under my mini spits, I have had quite a bit of trouble with both of them, one more than the other. Evidently they try to match pump speed with condensate flow, that produces a lot of noise on a continual basis. Interestingly,I just purched a new Aspen mini white pump that is located externally to the mini split, very similar to the Diversitech style but it uses a standard float and is designed to be easily cleaned. After a delay in this pump arriving it was explained to me that Diversitech just purchesed that division of Aspen. Another problem with the floatless units is they use a computer dc supply that draws current all the time, probably more on standby than a normal float style uses all year.



Also not to bash on Diversitech but I had one of their standard condensate pumps(the red one) with the float fail. The closed cell foam they use for the float actually became water logged under a condensing boiler and shut down the boiler. I was given another pump and so far so good.

Condensate pump on a Condensing Burner

The condensate from a condensing gas appliance is acidic and some condensate pumps are not rated for that use. If you are using a non-rated pump, you will see failures. So far that and a lack of maintenance are the only common problems I see with any regularity.