HTP MC120 - Manual (Page 50)

50
LP-171 Rev. 4.10.14
connection to the swirl plate and blower.
B. GAS PIPING
1. Run the gas supply line in accordance with all applicable codes.
2. Locate and install manual shutoff valves in accordance with state and local requirements.
3. In Canada, the Manual Shutoff must be identified by the installing contractor.
4. It is important to support gas piping as the heater is not designed to structurally support a large amount of weight.
5. Purge all gas lines thoroughly to avoid start up issues with air in the lines.
6. Sealing compound (pipe dope) must be used and approved for gas connections. Apply sparingly, and only to the male threads. Care
must be taken when applying compound to prevent blockage or obstruction of gas flow which may affect the operation of the heater.
Failure to apply pipe sealing compound as detailed above could result in substantial property damage, severe personal injury, or death.
CSA / UL listed flexible gas connections can be used when installing the heater. Flexible gas connections have different capacities and
must be sized correctly for the connected heater firing rates. Consult with the flex line supplier to assure the line size is adequate for the
job. Follow local codes for proper installation and service requirements.
Never use an open flame (match or lighter) to check for gas leaks. Use a soapy solution to test connection. Failure to use a soapy
solution test or check gas connection for leaks could result in substantial property damage, severe personal injury, or death.
Use a two-wrench method when tightening gas piping near the heater and its piping connection: One wrench to prevent the heater gas
line connection from turning; the second to tighten the adjacent piping. Failure to support the heater gas piping connection could
damage the heater beyond repair. Such damage IS NOT covered by warranty.
C. CHECK INLET GAS PRESSURE
The gas valve is equipped with an inlet gas pressure tap that can be used to measure the gas pressure to the heater. To check gas
pressure, perform the steps listed below:
1. IMPORTANT! Before you connect to the inlet pressure, shut off the gas and electrical power to heater.
2. Loosen the pressure tap with a small screwdriver. Refer to Figure 28 for location.
3. Each heater is equipped with a needle valve that will accept a 5/16 ID hose to connect to a digital manometer or liquid gauge
designed to measure incoming pressure from 0-
35” w.c. See Figure 28.
4. Turn on the gas and power up the heater.
5. Put the heater into manual test mode (details on test mode are in Part 12 Section D). 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 correct action that is needed to provide proper gas pressure to the
heater. If Gas Pressure is within normal range proceed to Step 6.
6. Exit test mode, then turn power off and shut off gas supply at the manual gas valve before disconnecting the hose from the gas
monitoring device. Tighten screw on the pressure tap and turn gas on. Check for leaks with soapy solution. Bubbles will appear on the
pipe to indicate a leak is present.
Ensure the pressure tap screw is properly tightened to prevent gas leaks. Failure to do so could cause substantial property damage,
severe personal injury, or death.