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ManualsBrandsCaleffi ManualsBoiler System AccessoriesThermoBloc Boiler Protection, Recirculation & Distribution Unit, 1-1/4" Sweat Connections, 140 F Standard

CALEFFI

ACCREDITED

ISO 9001 No. 0003

ISO 9001 FM 21654

0 1 2 3 4 5 6 7 8 9 10 11

(psi) (ft of head)

0.05

0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70

(gpm)

(lps)

ThermoBloc

™

boiler protection

recirculation and distribution unit

281 series

01224/12 NA

Function

The ThermoBloc

™

boiler protection recirculation and distribution unit

is used in hydronic heating systems with non-condensing boilers,

including solid fuel, biomass, gas LP or oil-ﬁred. It can be installed

with steel, cast iron and copper tube style boilers, automatically

controlling the return water temperature, protection against corrosion

from condensation occurring when a minimum ﬂue gas temperature

is not otherwise maintained. The ThermoBloc

™

unit is compact for

easy installation, reducing required space and ﬁttings. It combines the

functionality of a boiler protection valve with a circulation pump and a

unique ﬂapper check valve allowing for thermosyphon ﬂow between the

boiler and distribution system during a power outage. The ThermoBloc

™

includes three temperature gauges and is encased in an insulation shell.

Product range

281 series ThermoBloc

™

boiler protection recirculation and distribution unit ................................connections 1" and 1-1/4" NPT male and sweat union

Technical speciﬁcations

Materials - body: brass

- shutter: PSU

- spring: stainless steel

- ﬂapper check valve: PPS

- seal: EPDM

- thermostatic sensor: wax

Performance

Suitable ﬂuids: water, up to 50% glycol solutions

Max. working pressure: 150 psi (10 bar)

Working temperature range: 40–210°F (5–100°C)

Termperature gauge scale: 30–250°F (0–120°C)

Thermostatic sensor cartridge: 140°F (60°C) standard

Optional cartridges (consult factory): 115°F (45°C)

130°F (55°C)

160°F (70°C)

Sensor cartridge accuracy: ±3.6°F (±2°C)

Bypass from boiler complete

closing temperature: Tset +18°F (10°C)

Connections: - NPT male union 1" and 1-1/4"

- sweat union 1" and 1-1/4"

Insulation

Material: EPP

Mean thickness: 30 mm

Density: 45 kg/m3

Working temperature range: 40–210°F (5-100°C)

Thermal conductivity: 0.037 W/(m.K) at 10°C

Reaction to ﬁre (UL94): class HBF

Pump

Three-speed pump: Wilo Star S-16

Body: cast iron

Power supply: 115 V – 60 Hz

Max. pressure: 150 psi (10 bar)

Max. temperature: 230°F (110°C)

Agency approval: cULus

Wilo Star S-16 hydraulic characteristics

Summary of content (6 pages)

PAGE 1
ThermoBloc boiler protection recirculation and distribution unit ™ CALEFFI 281 series 01224/12 NA ACCREDITED ISO 9001 FM 21654 ISO 9001 No. 0003 Function The ThermoBloc™ boiler protection recirculation and distribution unit is used in hydronic heating systems with non-condensing boilers, including solid fuel, biomass, gas LP or oil-ﬁred.
PAGE 2
Dimensions Wood biomass and condensation build-up Wood contains a variable moisture content depending on the type (logs, pellets, woodchips, etc.). Water vapor is released during the solid fuel drying phase inside the combustion chamber. The presence of cold surfaces in the boiler or ﬂue gas chimney can lower the temperature of the ﬂue gas down to the dew point, causing condensation.
PAGE 3
Operating principle The thermostatic sensor, completely immersed in the medium, controls the movement of a shutter that regulates the bypass ﬂow from the boiler and toward the system. At boiler startup, the boiler protection recirculation and distribution unit recirculates the bypass ﬂow from the boiler to bring the boiler up to temperature as quickly as possible (ﬁg. 1).
PAGE 4
Construction details Single casting and reversibility The compact brass body casting houses the pump and all functioning components, offering easy installation, either on the right or left side of the boiler. The temperature gauges can be easily removed and reinserted on the back side of the unit. Brass body The brass body prevents the formation of ferrous residues in the system, prolonging boiler operating life.
PAGE 5
Application diagrams Non-condensing boiler system with buffer tank. Use safety devices according to local regulations Air separator Dirt separator Pump Shut-off valve Expansion vessel Check valve Motorized mixing valve Pressure reducing valve Filling unit Backflow preventer NONCONDENSING BOILER Safety relief valve Dirt separator for vertical pipes Air separator for vertical pipes Hydraulic separator Y-strainer Non-condensing boiler, connection to buffer tank in parallel.
PAGE 6
Non-condensing boiler, direct supply to the system. Use safety devices according to local regulations NONCONDENSING BOILER Non-condensing boiler, direct connection to buffer tank. Use safety devices according to local regulations NONCONDENSING BOILER SPECIFICATION SUMMARIES ThermoBloc series 281 Boiler protection recirculation and distribution unit. Connections 1" and 1-1/4" NPT male and sweat with unions. Brass body. Brass shutter locking nut. Polysulfone shutter. Stainless steel spring.