Central heating pump GRUNDFOS ALPHA1 L 25-40 180

Thanks to its compact design, PWM signal control capabilities, and operation at higher ambient temperatures, the ALPHA1 L is suitable for most heating installations and devices equipped with Grundfos pumps. This means you can easily replace a damaged or energy-inefficient pump, saving time and money.

The ALPHA1 L 25-40 180 pump has a number of advantages:

• Three fixed characteristics/fixed rotational speeds.
• Operating mode for radiator heating systems
• Operating mode for underfloor heating systems.
• Ability to cooperate with external devices (e.g. gas boiler) using a PWM signal with modulated pulse width.
• Maximum lift height 4 m and maximum flow rate 2.7m3/h
• Low energy efficiency index EEI < 0.20
• Easy and quick unlocking of the pump shaft using a screw located in the center of the panel
• Low noise level below 43 dB.
• Ceramic shaft prevents magnetic particles contained in heating water from settling on it.

PWM Signal

PWM input signal with profile A (heating). At high PWM signal percentage values (duty cycles), hysteresis prevents the pump from switching on and off in case of input signal fluctuations around the threshold value. At low PWM signal percentage values, pump speed is high for safety reasons. In case of cable damage (interruption) in an installation with a gas boiler, the pumps will continue to operate at maximum speed and receive heat from the heat exchanger. This function can also be used by circulation pumps in heating systems to ensure heat absorption in case of PWM line damage. If the PWM signal is unavailable, it is possible to set the ALPHA1 L pump to proportional-pressure constant-pressure regulation or fixed rotational speed.