HTP ELP-199 - Manual (Page 18)

18
LP-294 REV. 2.20.14
Install the boiler so the gas ignition system components are protected from water (dripping, spraying, etc.) Allow clearance for basic
service of boiler circulator, valves and other components.
Observe the minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not protected by non-
combustible materials.
On a boiler installed above radiation level, some states and local codes require a low water cut off device, which is an optional part
available through HTP (Part # 7450P-225). Check with local codes for additional requirements. If the boiler supplies hot water to
heating coils in air handler units, flow control valves or other devices must be installed to prevent gravity circulation of boiler water in the
coils during the cooling cycle.
Chilled water medium must be piped in parallel with the boiler. Freeze protection for new or existing systems must use glycol that is
specifically formulated for this purpose. Antifreeze must include inhibitors that will prevent the glycol from attacking the metallic system
components. Make certain that the system fluid is checked for correct glycol concentration and inhibitor level. The system should be
tested at least once a year and as recommended by the glycol solution manufacturer. Allowance should be made for expansion of the
glycol solution in system piping. Example: 50% by volume glycol solution expands 4.8% in volume for a temperature increase from 32
o F
to 180 o F, while water expands 3% with the same temperature rise.
G. PIPING DETAILS*
*NOTE: Systems shown are primary/secondary piping systems. These recommended systems have a primary (boiler) loop, and
secondary circuits for heating. The primary loop and secondary circuits have separate circulators. The use of other near boiler piping
configurations could result in improper flow rates, leading to inadvertent boiler high limit shutdowns and poor system performance.
Mixing valves are required for the protection of low temperature loops.
NOTE: In piping applications utilizing a single zone, it is recommended that the installer use flow / check valves with weighted seats at
or near the boiler to prevent gravity circulation.