Grundfos COMFORT 15-14 BX T Circulator Pump

The Grundfos COMFORT 15-14 BX T circulator pump, reference 93094846, is designed for domestic hot water recirculation in residential installations. Its operation keeps hot water circulating through the return pipe to reduce waiting time until DHW is available at the points of use and to limit the water wasted while it reaches the desired temperature.

This BX T version combines a brass pump housing suitable for drinking water with an integrated shut-off valve and check valve, external G 1 connection and automatic temperature control. It also features a low-consumption permanent magnet motor, integrated temperature sensor, dry-run protection and thermal insulation for the pump housing.

Circulator specifically for domestic hot water recirculation

The Grundfos COMFORT 15-14 BX T is specifically designed for domestic hot water recirculation circuits. The pump circulates water between the generator or storage tank and the points of use through a return line, helping keep hot water available in the installation.

Grundfos states that COMFORT pumps are intended for residential buildings and that, depending on the pipe layout, they can also be used in certain larger residential installations.

Automatic temperature control

The letter T identifies this version as a pump equipped with temperature control. The COMFORT continuously measures the water temperature using an integrated sensor and automatically adjusts its start and stop points.

It does not require the user to manually set an on or off temperature. The electronics determine the operating limits based on the maximum temperature detected in the circuit.

As an operating example, Grundfos indicates that if the maximum temperature detected in the system is 45 degrees Celsius, the pump may stop when the water exceeds approximately 41 degrees Celsius and restart when it drops below about 38 degrees Celsius.

The maximum system temperature is re-evaluated periodically, allowing the control to adapt to the actual conditions of the installation.

T version without timer or AUTOADAPT

The COMFORT 15-14 BX T must be distinguished from the TDT and TA variants in the same family. This model specifically features automatic temperature control.

• COMFORT T: temperature-based control.
• COMFORT TDT: timer and temperature control.
• COMFORT TA: AUTOADAPT control based on consumption habits and temperature.

Reference 93094846 corresponds to the BX T version, so it does not include the digital timer of the TDT variant or the habit-learning function of the TA version.

Maximum flow rate of 0.5 cubic metres per hour

The COMFORT 15-14 range offers hydraulic performance specifically sized for DHW recirculation circuits:

• Maximum flow rate: 0.5 cubic metres per hour.
• Maximum head: 1.2 metres.
• Maximum outlet pressure: 10 bar.
• Minimum inlet pressure: 0.05 bar.

These performance values make it possible to maintain the circulation required in domestic hot water return circuits without using an oversized pump for the application.

Electrical consumption of only 5 to 7 watts

The Grundfos COMFORT incorporates a permanent magnet motor designed to deliver low electrical consumption.

• Power consumption: 5 to 7 watts.
• Supply: 1 × 230 volts.
• Frequency: 50/60 hertz.
• Appliance class: double insulation.
• Protection rating: IP44.

The pump is supplied with an approximately 1.5-metre power cable and plug, making electrical connection easier during installation.

Sphere rotor motor

The COMFORT uses a sphere rotor design. Grundfos uses this construction to reduce the risk of blockage caused by limescale deposits and to facilitate operation with water of different hardness levels.

The manufacturer specifies that the pump can operate with water hardness without a specified limit, a particularly relevant feature in DHW installations located in hard-water areas.

Dry-run protection

The pump includes electronic dry-run protection. If the unit runs mainly with air, the electronics repeatedly stop the rotor to protect the bearing.

Once the circuit is properly filled and vented, the pump can resume normal operation.

Brass housing for drinking water

The hydraulic housing is made of brass, a material used by Grundfos in this family for contact with drinking water.

The pump also has approvals for drinking water applications such as UBA, WRAS and ACS, together with CE and VDE safety approvals.

Integrated shut-off and check valves

The BX designation identifies the version factory-fitted with:

• Integrated shut-off valve.
• Integrated check valve.

These valves make installation and maintenance easier. The check valve prevents reverse flow, while the shut-off valve allows the pump to be isolated during certain interventions.

External G 1 connection

Reference 93094846 has G 1 external connections and an installation length of 140 millimetres.

• Connection: G 1 external thread.
• Connection length: 140 millimetres.
• Approximate net weight: 1.14 kilograms.
• Approximate gross weight: 1.24 kilograms.

These characteristics should be checked against the available space and existing connections when the pump is used as a replacement for another circulator.

Water temperature up to 95 degrees Celsius

Grundfos specifies a wide temperature range for the pumped liquid:

• Minimum liquid temperature: 2 degrees Celsius.
• Maximum liquid temperature: 95 degrees Celsius.

The pump is intended exclusively for circulating drinking water within the conditions indicated by the manufacturer.

Low noise level

The permanent magnet motor and rotor construction allow quiet operation. Grundfos declares a noise level of 22 dB(A) or less.

This low acoustic level is especially suitable for residential installations where the pump may be located near living areas.

Thermal insulation included

The pump is supplied with a pump housing insulation shell. This element helps reduce heat losses from the brass housing to the surrounding environment.

Temperature control complements this feature by preventing the pump from having to run continuously when the water in the circuit is already at a sufficient temperature.

Reduced heat losses through temperature control

Compared with a circulator running continuously 24 hours a day, Grundfos indicates that temperature control mode can help reduce the heat losses associated with recirculation.

According to the comparative data published by the manufacturer for the COMFORT range, T control can reduce recirculation heat losses by approximately 25% compared with continuous operation, although actual savings depend on the installation, insulation, temperatures and usage habits.

Compact installation

The compact design makes installation easier in confined spaces. Grundfos allows different head orientations, provided the positions and requirements indicated in the installation instructions are respected.

For versions with temperature control, Grundfos recommends avoiding direct exposure of the sensor to the heat from the DHW generator. Among other instructions, it sets a minimum distance of approximately 50 centimetres from the water heater.

Installation and commissioning

Before putting the pump into operation, the circuit must be properly filled, flushed and vented to remove air.

The COMFORT includes dry-run protection, but the manufacturer states that this function must not be used as a substitute for correct circuit commissioning.

During installation, the flow direction indicated on the pump housing must also be respected.

Easy maintenance

The detachable design allows the head to be separated from the housing for cleaning tasks. The rotor can be removed to eliminate possible limescale deposits following Grundfos maintenance instructions.

The integrated shut-off valve in the BX version simplifies certain operations on the motor without the need to completely drain the circuit.

Applications of the Grundfos COMFORT 15-14 BX T

The pump is mainly intended for DHW recirculation circuits in residential installations with a return line.

It can be part of installations with different hot water production systems, provided the hydraulic configuration is compatible and the operating conditions indicated by Grundfos are respected.

Scope of delivery

According to Grundfos documentation, the supply includes:

• COMFORT 15-14 BX T circulator pump.
• Integrated power cable with plug.
• Insulation shell for the pump housing.
• Integrated shut-off valve in the BX version.
• Integrated check valve in the BX version.
• Quick installation and operating guide.

Technical characteristics of the Grundfos COMFORT 15-14 BX T

• Brand: Grundfos.
• Range: COMFORT.
• Model: COMFORT 15-14 BX T.
• Reference: 93094846.
• Application: domestic hot water recirculation.
• Fluid: drinking water.
• Control mode: automatic temperature control.
• Temperature sensor: integrated.
• Maximum flow rate: 0.5 cubic metres per hour.
• Maximum head: 1.2 metres.
• Liquid temperature: 2 to 95 degrees Celsius.
• Maximum outlet pressure: 10 bar.
• Minimum inlet pressure: 0.05 bar.
• Housing material: brass.
• Connection: G 1 external.
• Installation length: 140 millimetres.
• Check valve: integrated.
• Shut-off valve: integrated.
• Motor: permanent magnet.
• Rotor design: sphere rotor.
• Power consumption: 5 to 7 watts.
• Voltage: 230 volts.
• Frequency: 50/60 hertz.
• Electrical class: double insulation.
• Protection rating: IP44.
• Noise level: 22 dB(A) or less.
• Dry-run protection: yes.
• Permissible water hardness: no limit specified by Grundfos.
• Power cable: approximately 1.5 metres with plug.
• Housing insulation: included.
• Approximate net weight: 1.14 kilograms.
• Drinking water approvals: UBA, WRAS and ACS.
• Safety approvals: CE and VDE.

DHW recirculation with automatic control and low consumption

The Grundfos COMFORT 15-14 BX T combines in a compact unit the main functions needed for a domestic hot water recirculation installation: brass housing for drinking water, automatic temperature control, check valve, shut-off valve, dry-run protection and a permanent magnet motor consuming only 5 to 7 watts.

Its G 1 connection, 140-millimetre installation length, quiet operation and automatic thermal regulation make reference 93094846 a particularly practical solution for DHW installations that need hot water quickly and want to avoid unnecessary continuous pump operation.