Just can't seem to adjust the temp. It flashes 77, but the temp stays at 75. Why?

I was having the same problem, though mine was stuck at 74.5--it stayed blue and never got higher, though it was set to 77. I called Hagen, and they said try unplugging it for 10 minutes, then plug it back in to see if that helps. It didn't; they'd said if that was the case it was defective and to return it. Mine was <1 week old.

I just bought this item September of last year and it wont let me adjust the temperature after the initial setting when I first had it

So you move the adjusting orange dial/thingy and doesn't change temp? Some times you have to move it all the way, let it return to the neutral position and the move it again to and so on. If that doesn't work, it may be faulty, contact Fluval, these have good warranty.

does this heater go in the tank

To clear any confusion, the heater is fully submersible to 39 inches. The photos in the instruction showing tank placement are misleading. The ones marked with an X means do not let it hang by the cord and do not just lay it on the bottom of the tank. Rest assured that the unit is sealed well and you are better off fully submerging the unit to prevent water evaporation from negatively affecting the heater.

Will I have "low flow" problems running only sponge filters?

Your air pump running the sponge filters circulate the water. The pump power will determine whether or not there is “low flow.”

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Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

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Fluval E 300 Watt Electronic Heater

Q: I just bought this item September of last year and it wont let me adjust the temperature after the initial setting when I first had it

So you move the adjusting orange dial/thingy and doesn't change temp? Some times you have to move it all the way, let it return to the neutral position and the move it again to and so on. If that doesn't work, it may be faulty, contact Fluval, these have good warranty.

Q: does this heater go in the tank

To clear any confusion, the heater is fully submersible to 39 inches. The photos in the instruction showing tank placement are misleading. The ones marked with an X means do not let it hang by the cord and do not just lay it on the bottom of the tank. Rest assured that the unit is sealed well and you are better off fully submerging the unit to prevent water evaporation from negatively affecting the heater.

Q: Will I have "low flow" problems running only sponge filters?

Your air pump running the sponge filters circulate the water. The pump power will determine whether or not there is “low flow.”

Product ID: 2221553

Details

Brand
Fluval
Capacity
100 gallons
Color
Blue
Power Source
Corded
Wattage
300 watts

🧠Dual sensor microprocessor control

🌡️300W precise heat output

🛡️Integrated fish guard safety

COP 347399

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Description

🌊 Heat with precision, protect with passion.

TRUSTED DURABILITY - Backed by a 5-year warranty, this heater is built to keep your tank thriving long-term.
SAFETY FIRST DESIGN - Advanced integrated fish guard protects your aquatic friends from harm, because they deserve the best.
SLEEK SPACE SAVVY - Slim mounting bracket fits seamlessly into any aquarium setup without clutter or fuss.
SMART DUAL SENSOR TECH - Real-time temperature monitoring powered by an intelligent microprocessor ensures no surprises.
PRECISION HEATING MASTERY - Maintain your aquatic ecosystem with ultra-accurate 0.5°C increments for optimal fish comfort.

The Fluval E 300 Watt Electronic Heater is a cutting-edge aquarium heater featuring a dual sensor microprocessor system for precise temperature control in 0.5-degree increments. Designed for tanks up to 100 gallons, it continuously monitors water temperature and includes an integrated fish guard for enhanced safety. Its slim mounting bracket ensures a neat installation, and a 5-year warranty guarantees reliable performance for your aquatic environment.

Specifications

ASIN	B001VMSK0I
Best Sellers Rank	#17,614 in Pet Supplies ( See Top 100 in Pet Supplies ) #21 in Aquarium Heaters
Brand Name	Fluval
Capacity	100 gallons
Color	Blue
Customer Reviews	4.3 4.3 out of 5 stars (6,226)
Global Trade Identification Number	00015561107747
Heat Output	300 Watts
Included Components	Fluval Advance Electronic Aquarium Heater (300 Watt)
Is Electric	Yes
Item Type Name	HAGEN FLUVAL E 300W HEATER
Item Weight	0.37 Kilograms
Manufacturer	Rolf C. Hagen (USA) Corp.
Manufacturer Part Number	A774
Manufacturer Warranty Description	5 years; fluval e series heaters are guaranteed against defects in material or workmanship under normal aquarium usage and service for 5 years. We offer a 5 year guarantee on all nonreplaceable parts which means that the heater will be repaired or replaced at the manufacturer's discretion, free of charge, when the complete heater is returned with proof of purchase and postage paid. This warranty d…
Material Type	Plastic
Model Number	A774
Mount Type	Slim mounting bracket
Power Source	Corded Electric
Style Name	E300
UPC	015561107747 015561014168
Unit Count	1.0 Count
Voltage	230 Volts
Wattage	300 watts

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