Eheim used to be a great quality product. I have been using their aquarium products for decades. Now the last two heaters I bought have failed within 30 days.
Tetra HT Submersible Aquarium Heater: Efficiently Regulate Temperature with Electronic Thermostat
9 Review
π Fluval E300 Electronic Heater - 300W Advanced Aquarium Heater for Tanks up to 100 Gallons (A774)
9 Review
Convector Electrolux ECH/T-2000 M, white
21 Review
Hardy Leaf Black Forest Asian Java Fern Potted Live Water Aquatic Aquarium Plants For Freshwater Fish Tank By Greenpro Microsorum Pteropus
39 Review
Mini pump Xiaomi Mijia Electric Pump 1S, plastic, black
55 Review
Jasonwell Magnetic Aquarium Fish Tank Glass Algae Cleaner - Floating Brush (L Size)
37 Review
Vacuum cleaner TEQQO Aquastick 3 in 1 Power, grey/turquoise
26 Review
Efficient 2-In-1 Magnetic Fish Tank Cleaner With Non-Slip Design And Scratch-Free Blades
37 Review