43
2. Loosen the pressure tap with a small screwdriver. Refer to Figs. 20 and 21 for locations.
3. Each unit is equipped with a needle valve that will accept a 5/16 ID hose to connect to a digital
manometer or liquid gauge to measure incoming pressure from 0-35” w.c.
4. Turn on the gas and power up the unit.
5. Put the unit into manual service mode (details on service mode are in the back of this manual). In
service mode, monitor pressure to assure it does not drop below 1 inch from its idle reading. If gas
pressure is out of range, or pressure drop is excessive, contact the gas utility, gas supplier, qualified
installer, or service agency to determine the correct action needed to provide proper gas pressure to the
unit. If gas pressure is within normal range, proceed to Step 6.
6. Exit Service mode, then turn power off and shut off the gas supply at the manual gas valve before
disconnecting the hose from the gas monitoring device. Tighten the screw on the pressure tap, turn gas
on, and check for leaks with a soapy solution. If a leak is present, bubbles will appear on the pipe.
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.
Summary of Contents for Mod Con 300 HL
Page 13: ...13 Figure 2 ...
Page 31: ...31 Figure 13 ...
Page 37: ...37 J SIDEWALL VENTING DIAGRAMS Figure 16 Sidewall Venting with Tee and Coupling ...
Page 38: ...38 Figure 17 Sidewall Venting Diagrams ...
Page 39: ...39 K VERTICAL VENTING DIAGRAMS Figure 18 Two Pipe Roof Venting with Tee and Coupling ...
Page 40: ...40 Figure 19 Roof and Sidewall Venting with Stainless Steel ...
Page 44: ...44 E GAS VALVE Figure 21 ...
Page 45: ...45 Figure 22 ...
Page 55: ...55 Figure 28 Mod Con Internal Connection Diagram ...
Page 73: ...73 Figure 32 ...
Page 74: ...74 Figure 33 ...
Page 75: ...75 Figure 34 ...
Page 76: ...76 Figure 35 ...
Page 77: ...77 Figure 36 ...
Page 80: ...80 ...
Page 81: ...81 ...
Page 82: ...82 MAINTENANCE NOTES ...
