Instructions / Assembly
Installing Your Heater 
6 
The  following  steps  are  needed  for  proper  installation  and  safe 
operation of  your heater.    If you  have  any doubts  as to  any 
requirements,  check  with  local  authorities  for  local  and  state 
codes affecting the installation. 
Obtain professional help where needed. 
DO NOT install this heater in a travel trailer, recreational vehicle, 
or mobile home. 
IMPORTANT 
For satisfactory and trouble-free operation, be sure to: 
1.  Locate the heater properly within the space to be heated. 
2.  Provide for adequate combustion air, adequate air circulation 
around  the  cabinet  inside  the  open  room  and  a  proper  vent 
system. 
3.  Maintain all minimum clearances which apply to your heater. 
Locating the Heater 
WARNING: Gas burning appliances require air for 
combustion and proper venting.  Minimum fresh air 
opening  of  1  square  inch  per  1,000  Btu/hr.  input 
rating must be provided for ventilation. 
EXAMPLE: A 30,000 Btu/hr. input unit requires the equivalent of a 
30 inch wide window be open 1 inch for safe operation. 
WARNING:  Danger  of  property  damage,  bodily 
injury  or  death.    Even  when  a  house  meets 
requirements  for  unconfined  space  with  adequate 
air  infiltration,  it  is  recommended  that  a  fresh  air 
intake  be  installed to  lessen  the  possible dangers 
from any future changes on the home. 
Consider  the  following  points  before  attempting  to  install  the 
heater: 
1.  In choosing the  location for the  heater, the  following factors 
should be considered: 
a.  Convenience to the gas supply. 
b.  Arrangement of the rooms or area to be heated. 
c.  Probable location of the furniture. 
d.  General appearance. 
e.  Safe clearance from anything that could catch fire. 
f.  Ability to properly vent the heater. 
2.  Locate the heater centrally in the area which it is to heat. The 
ideal location is at the source of cold air, which is an outside 
wall.  If the heater is on an outside wall, the cold air will be 
warmed before it moves through the room. 
3.  Place the heater where the air will circulate freely throughout 
the area to be heated.  If one heater is intended to heat the 
entire house,  it is advisable  to consider the  installation of 
grilles immediately below the ceilings to permit circulation of 
hot  air  from  room  to  room.  Return  air  grilles  are  also 
desirable. 
4.  Be  certain  the  heater  is  placed  where  the  air  is  free  to 
circulate around it. Never install the heater in a wall recess. 
The minimum clearance required to any wall or object can be 
found  on  the  rating  plate  located  inside  the heater  control 
door  on  the  base  plate.  We  recommend  a  24-inch  min. 
clearance from the burner access door for the ease of lighting 
and for observation of pilot and burner flames. 
5.  The heater must be installed so that the draft hood is in the 
same pressure zone as the combustion air. 
6.  The  heater  may  be  placed  directly  on  wood  floors.    Heavy 
pile  or  shag  rugs  may  restrict  normal  air  flow.    Some  floor 
coverings discolor easily from even low heat.  To assure safe 
operation,  a  metal  or  wood  panel,  extending  the  full  depth 
and width of the appliance must be placed under the heater. 
Optional floor boards are available from Williams. 
7.  Do  not place  the  heater where curtains,  draperies, or  any 
other  material  may  come  into  contact  with  any  part  of  the 
heater. 
GAS CONTROLS 
1.  All  models  are  regulated  on  natural  or  L.P.  Gases.  The 
regulator is built into the gas control valve. 
2.  All models are equipped with a 100% pilot safety shutoff and 
vent safety shutoff system. 
3.  CAUTION: Do not connect 115V electrical service line to gas 
control valve or wall thermostat. 
GAS SUPPLY 
For  natural  gas,  the  minimum  inlet  gas  supply  pressure  for  the 
purpose  of  input  adjustment  is  5"  water  column.  The  Maximum 
inlet gas supply pressure is 7" water column. 
For  L.P.  Gas,  the  minimum  inlet  gas  supply  pressure  for  the 
purpose of  input adjustment is 11" water column. The maximum 
inlet gas supply pressure is 13" water column. 
The gas pressure and input to the burners must not exceed the 
rated  input  and  pressure  shown on  the  rating  plate.  On  Natural 
Gas, the manifold pressure should be 4 inches water column. The 
manifold pressure should be 10 inches water column for L.P. Gas.  
Orifice changes may be required to suit the gas supplied. 
For  heaters  located  at  elevations  between  sea  level  and  2,000 
feet, the measured input must not be greater than the input shown 
on the rating plate of the heater.  For elevations above 2,000 feet, 
the measured input must not exceed the input of the rating plate 
reduced by 4 percent for each 1,000 feet that the heater is above 
sea level. 
MINIMUM REQUIRED CLEARANCES 
MODEL 
"A" SIDE 
"B" CEILING 
"C" REAR 
200 SERIES 
350 SERIES 
500 SERIES 
650 SERIES 
2" 
6" 
6" 
6" 
36" 
57" 
57" 
57" 
3" 
6" 
6" 
6" 
24”  min.  Clearance  is recommended  on  side  with  burner  access 
door  for ease of  lighting  and for  observation of  pilot  and  burner 
flames. 










