Suction Cups on Jager (or other) Heater

[punman]

I see some tank photos where the submersible heater is mounted at the back or side of the tank in a horizontal or diagonal configuration. I can never get mine to stick, and even in a vertical position it does not work and I end up taking the suction cups off and let the heater hang. Brand of heater does not seem to make any difference when I try the suction cups. What is the trick here?

 

[tlindsey]

Brand of heater does not seem to make any difference when I try the suction cups.

I've had the same experience with heaters. The area has to be free of biofilm or algae and suction cups do wear out.

 

[neutrino]

I've had the same experience with heaters. The area has to be free of biofilm or algae and suction cups do wear out.

+1 to both, but I find I have to replace them every so often-- same for canister tubes, really, suction cups quit sticking eventually and I replace them.

 

[Denon]

I've had really good luck with these things for my eheim jager heaters. https://www.amazon.com/gp/product/B07J9QJ7YX/