2. Baxi AquaHeat HIUs

Commercial Solutions

Heat Interface Units

For homes fed with heat from a heat network, the Baxi AquaHeat HI/HWI (Heating Indirect/Hot Water Indirect)is the answer to your apartment’s heating and hot water requirements.


The Baxi AquaHeat HD/HWI (Heating Direct/Hot Water Indirect) provides an alternative highly efficient, low cost solution and the Baxi AquaHeat HI (Heating Indirect) is perfectly suited to supply heat to communal and commercial premises in your development.

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DIRECT HIU
INDIRECT HIU

Features and Benefits

Multiple outputs

Range of heating outputs from 4kW to 60kW and domestic hot water outputs from 18kW to 57kW.

Easy installation

Optional first fix rail with in-built filling loop and stand-off bracket to allow for installation with various primary and tertiary pipework. Pre-wired with heat meter and Mercurius remote monitoring module.

Highly efficient

Ultra-fast acting, fully modulating PICV perfectly matches energy supply to instantaneous demand and high performance insulation providing very low heat losses.

Remote monitoring and control

Mercurius platform for remote monitoring to reduce site on time and giving visibility of errors to improve first-time fix rates.

Reliable

Water Regulation WRAS and Reg4 approved. BESA 2023 V3 compliant in preparation for HNTAS market regulation. Covered with a 5-year parts and labour warranty.*

BESA 2023 V3 accredited

High performing Indirect HIU with 8 best practice passes. The first BESA 2023 certified Direct HIU with best practice Heat Loss performance.
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Product Literature

Specification Guides

Specification Guides

Technical Specifications

Technical Specifications

BIM Files

BIM Files

Baxi Aquaheat HIU

Baxi AquaHeat HIU
BIM file

Reports

Reports

TM65

TM65

Baxi AquaHeat HIU - Heat Interface Unit Dimensions

AquaHeat HI

Dimensions

A: HIU width = 540mm 

B: HIU height = 857mm

C: HIU depth = 260mm

D: Side Clearance = 30mm

E: Upper Clearance =100mm

F: Lower Clearance = 30mm

G: Front Clearance (in operation) = 200mm 

 

Service clearances shown here are the minimum

recommended dimensions. Greater clearance will 

aid installation and maintenance.      

Baxi AquaHeat HI/HWI Heat Interface Unit Dimensions

AquaHeat HI/HWI

Dimensions

A: HIU width = 540mm

B: HIU height = 750mm

C: HIU depth = 260mm

D: Side Clearance = 30mm

E: Upper Clearance = 100mm

F: Lower Clearance = 30mm

G: Front Clearance (in operation) = 200mm 

 

Service clearances shown here are the minimum

recommended dimensions. Greater clearance will 

aid installation and maintenance.      

aquaheat-hdhwi-dimensions.png

AquaHeat HD/HWI

Dimensions

A: HIU width = 300mm

B: HIU height = 544mm

C: HIU depth = 250mm

D: Side Clearance = 30mm

E: Upper Clearance = 30mm

F: Lower Clearance = 100mm

G: Front Clearance (in operation) = 200mm

 

Service clearances shown here are the minimum 
recommended dimensions. Greater clearance will 
aid installation and maintenance.

Technical Specification 

Product ModelAquaHeat HI/HWI - 4/50AquaHeat HI/HWI - 4/50AquaHeat HI/HWI - 14/50AquaHeat HI/HWI - 14/50AquaHeat HI - 50AquaHeat HI - 50AquaHeat HD/HWI - 12/50AquaHeat HD/HWI - 12/50
with Heat Meter & Mercuriuswith Heat Meter & Mercuriuswith Heat Meter & Mercuriuswith Heat Meter & Mercurius
Product Code78674707867472786747678674777867474786747578922847892283
Net Weight (Dry) (kg)2726.52726.7303010.510.5
Net Weight (Wet) (kg)27.52727.527.231.531.51111
Gross Weight (packaged) (kg)2726.52726.7303010.510.5
Height (packaged) (mm)750750750750857857544544
Width (packaged) (mm)540540540540540540300300
Depth (packaged) (mm)260260260260260260250250
Heat Loss in keep warm mode high temp (DH 70°C) (kWh / 24h)0.950.950.950.95--0.610.61
Heat Loss in keep warm mode low temp (DH 55°C) (kWh / 24h)0.910.910.910.910.690.69
Primary Side
Max operating pressure (bar)16161616161666
Max operating temperature (˚C)9090909090909090
Maximum primary flow rate (DHW mode) (55 primary / 50 dhw (m3/h)0.90.90.90.9--0.90.9
Maximum primary flow rate (space heating mode) (55 primary / 45/35 CH) (m3/h)0.260.260.60.6330.50.5
Maximum primary pressure differential (kPa)600600600600600600
Min primary pressure drop req. at Maximum primary flow rate (DHW Mode) (kPa)16161616--1616
Space Heating hydraulics
Max operating pressure (bar)2.52.52.52.53366
Max operating temperature (˚C)8585858585859090
Safety relief valve setting (bar)333333N/AN/A
Heating temperature setpoint (min - max) (˚C)15 - 8515 - 8515 - 8515 - 8515 - 8515 - 8515 - 9015 - 90
Heating temperature setpoint (default) (˚C)4545454545455555
Heating nominal pump head (kPa)70707070--N/AN/A
DHW hydraulics
Max operating pressure (bar)10101010--1010
Min cold water supply pressure (bar)1111--11
Hot water temperature setpoint (min-max) (˚C)40-6540-6540-6540-65--40 - 6540 - 65
Hot water temperature setting (default) (˚C)50505050--5050
Electrical
Power supply (V / Hz)230V ~50 Hz230V ~50 Hz230V ~50 Hz230V ~50 Hz230V ~50 Hz230V ~50 Hz230V ~50 Hz230V ~50 Hz
Permanent live required (yes/no)yesyesyesyesyesyesyesyes
Power consumption (max space heating output) (W)6565656565656565
Power consumption (standby) (W)33333333
Power consumption (max space heating output, with Mercurius) (W)7575757575757575
Power consumption (standby, with Mercurius) (W)1313131313131313
Minimum external fuse rating (A)55555555
Internal fuse rating (A)55555555
Connection Types / Sizes
Primary network flow3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Primary network return3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Space heating flow3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Space heating return3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Cold water feed3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Domestic hot water flow3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male3/4 ISO G 228 male1 female1 female3/4 ISO G 228 male3/4 ISO G 228 male
Space heating safety valve discharge (mm)151515151212N/AN/A

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