HTP 850 LPHL - Manual (Page 37)

37
LP- 205 REV. 3.28.14
The gas piping must be sized for the proper flow and length of pipe to avoid pressure drop. The gas meter and regulator must be
properly sized for the total gas load. If you experience a pressure drop greater than 1" w.c. (.87 kPa), the meter, regulator or gas line
may be undersized or in need of service. You can attach a manometer to the incoming gas drip leg after removing the cap. The gas
pressure must remain between 3.5" (.87 kPa) and 14" (3.5 kPa) during stand-by (static) mode and while in operating (dynamic) mode.
If an in-line regulator is used, it must be a minimum of 10 feet from the boiler. It is very important that the gas line is properly
purged by the gas supplier or utility. Failure to properly purge the lines, or improper line sizing, will result in ignition failure.
This problem is especially noticeable in NEW LP installations and empty tank situations. This situation can also occur when a utility
company shuts off service to an area to provide maintenance to their lines. This gas valve must not be replaced with a conventional gas
valve under any circumstances.
DO NOT adjust or attempt to measure gas valve outlet pressure. The gas valve is factory-set for the correct outlet pressure and
requires no field adjustment. Attempts by the installer to adjust or measure the gas valve outlet pressure could result in damage to the
valve and cause substantial property damage, severe personal injury, or death.
E. GAS VALVE
Figure 20 – Mod Con 300/500 Gas Valve