w w w . c a l e f f i . c o m
1
NA10294.03
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.
These items are designed for use in closed hydronic systems. Do not use
in plumbing applications. These items do not meet the low-lead plumbing
standards of U.S. and Canada.
Product range
281 series boiler protection recirculation and distribution unit. NPT
male or sweat, sizes 1”, 1-1/4”.
Technical Characteristics
· Materials: - Body:
brass
- Shutter:
PSU
- Spring:
stainless steel
- Flapper check valve:
PPS
- Seal:
peroxide-cured EPDM
- Thermostatic sensor:
wax
· 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:
130°F (55°C) standard
115°F (45°C), 140°F (60°C),
160°F (70°C) optional cartridges
· 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”
281 Series
Installation, commissioning and servicing instructions
© Copyright 2018 Caleffi
ThermoBloc™ boiler protection recirculation and distribution unit
