Clearances and Height Requirements | Monessen Hearth NB24, NB18

CLEARANCES and HEIGHT REQUIREMENTS

Heat resistant material (minimum requirements) with no wooden mantel or other combustible projection:

To install the gas logs into a fireplace with no wooden mantel, shelf or other combustible projection above the fireplace opening, measure the heat resistant material height, per Figure 5, then see TABLE A.

Heat resistant materials such as slate and marble must be at least 1/2” thick. Sheet metal should not be installed onto combustible material.

IMPORTANT: If you cannot meet these minimum clearances you must operate the heater with chimney flue damper open. Refer to “Installing Vented Applications” found on page 18.

Heat

Resistant

Material

Measure

this

distance

Heater in

Fireplace or

Firebox

Figure 5 - Measuring Heat Resistant Material

HEAT RESISTANT	REQUIREMENTS FOR SAFE INSTALLATION
MATERIAL
MATERIAL	NB18	NB24
MEASUREMENT
12" or more	Hood not required.	Hood not required.
8" to less than 12"	Hood not required.	Extend heat resistant material
		to 12" OR install hood. See
		Figure 5.
Less than 8"	Extend heat resistant material	Extend heat resistant material
	and 8” AND install hood. See	to 8" AND install hood. See
	Figure 5.	Figure 5. OR, extend heat
		resistant material to a height of
		at least 12".

TABLE A - Heat Resistant Material Requirements with no Mantel or Combustible Projection

12

81D0107

Image 12

Monessen Hearth NB24, NB18 operating instructions Clearances and Height Requirements

Contents

Model NB18, NB24 Read and Save These InstructionsWhat to do if YOU Smell GAS Contents Important Safety Information InstallerOwner Massachussetts Residents only What YOU will Need for Installation Getting StartedMake Sure YOU have Received ALL Parts Product Features and Specifications General Installation Information CodesAdequate Combustion and Ventilation AIR BTU / Hr = Fireplace and Hearth Dimensions Model Placement in a Fireplace with a Restrictive Barrier Height of Restriction Minimum Depth of Fireplace/Firebox Clearances and Height Requirements Sidewall and Ceiling Clearances Clearances and Height Requirements Measuring Heat Resistant Material for Mantel Minimum Mantel Clearance with No Hood -NB18 Mum of 10 at a minimum of 28 above the opening Floor Clearance Minimum Clearance above Combustible Flooring Installing Vented Applications Before Fully Installing the UnitBefore Installing the Appliance Damper Stop Installation Installing Vented Applications Assembly ProcedurePlacing and Securing Appliance Connecting the GAS Flexible Tube Manual Shutoff Gas Supply Inlet Valve Checking GAS Pressure Millivolt Valve Control Figure Electrical Wiring Millivolt Connecting Optional Wall Switch or ThermostatATE Connecting Remote Receiver Checking System OperationComplete Millivolt System Check LOG Placement Placing Rock Wool Placing Log #3 EMBER, GRATE, and Rock Installation Cast Iron Grate InstallationPlacing Flickering Embers Placing the Decorative Rock Flame Appearance Checking the Pilot FlameMillivolt Control and Thermostat Control Checking the Burner Flame Operating Instructions Operating Instructions What to do if YOU Smell GAS To Turn OFF GAS to Heater Operating Instructions and Cleaning and Servicing Cleaning and Servicing Troubleshooting Observed Problem Possible Cause Remedy ODS/pilot lights, but flame Replacement Parts Burner Assembly Replacement Parts List Accessories Sold Separately Berkley OAK Refractory Logs Description Qty BO18-R BO18-F BO24-R BO24-F BO30-R BO30-F Carbon Monoxide Detector Requirements Special Requirements 81D0107 81D0107 Lifetime Warranty Five Year WarrantyBasic Warranty