15
XTherm heaters are equipped with an integral cold
water protection system, which uses a proportional
two-way valve and injection pump to modulate the
return water flow, forcing the boiler pump to pull water
from the boiler outlet to the inlet during operation.
This feature allows the system to achieve and main-
tain a specific inlet temperature target. H models are
designed to operate with system return water tem-
peratures down to 50°F continuous. Under start up
conditions the injector system can operate with fluid
temperatures below 50ºF. Continuous operation below
50ºF return water temperature may cause operational
issues for the unit as well as temperature control insta-
bility. XTherm WH models are equipped with pumps
and proportional valves, which are constructed with
materials appropriate for domestic hot water operating
conditions. Contact your local representative or the
factory for applications assistance.
Hydronic Heating
NOTE:
Injection Pump is field-installed outside the
cabinet, as shown in the piping diagrams.
Fig. 12: High Temp Potable and Process Open Loop: H model, Single with Storage Tank
Fig. 13: High Temp Potable and Process Open Loop: H model, Cascade with Storage Tank
Fig 11: System Sensor Installation
System
Sensor
Thermal
Paste
Drywell
NPT
Fitting
