Williamson-Thermoflo SCH High Boy, Manual Manual

SCH & SCL

Oil Furnaces

 – 

Furnace Manual

670-000-006-1007  

5

Connect fuel oil piping 

General oil piping requirements 

•

  Location and installation of oil tanks, oil piping and burners 

must follow: 

•

  NFPA 31, Standard for the Installation of Oil-Burning 

Equipment. 

•

  In Canada, CSA B139, Installation of Oil-Burning 

Equipment. 

•

Local codes and regulations. 

•

Information provided with burner and fuel pump. 

•

  If any part of fuel oil tank is above level of burner, an anti-

siphon device must be used to prevent flow of oil in case of 
oil line break. 

•

Support oil lines as required by codes. 

•

Make tank connections with swing joints or copper tubing to 
prevent breaking in case the tank settles. Make swing joints 
so they will tighten as tank settles. Non-hardening pipe joint 
compounds should be used on all threads. 

Do not use Teflon tape as an oil pipe sealant. It 
can cause valves to fail, creating hazards. Use 
only flare fittings. Do not use compression fittings. 
Failure to comply could result in severe personal 
injury, death or substantial property damage from 
oil leakage and/or fire hazard. 

•

  Underground pipe must be run in a casing to prevent oil 

leaking into ground or under floor. Check local codes for 
information. 

Oil piping connection at burner 

•

Connect oil line to burner using a flare fitting. 

Use of any connection other than a flare fitting at 
the oil connection to the burner could result in a 
fuel oil leak, with the potential for severe personal 
injury, death or substantial property damage. 

•

  See local codes for appropriate arrangement and piping of 

filter, control valves, etc. connecting to oil tank. 

•

  Refer to burner manual for oil system requirements. Verify 

that suction lift does not exceed stated limit. Where lift 
exceeds limit for a one-pipe system, use a two-pipe system 
as directed in burner manual. 

Electric shock hazard. Can cause severe 
personal injury or death if power source, including 
service switch on furnace, is not disconnected 
before installing or servicing. 

6

Wire furnace & burner 

Wire burner 

The burner harness is factory-wired to the furnace at the factory. 
Plug the burner harness into the mating burner connector to wire 
the burner. Refer to the wiring diagram on pages 16 and 17 for 
further information. 
 
 

Install and wire thermostat / shut-off 
system 

Mount the room thermostat on an interior wall in the natural 
circulating path of room air. Do not locate the thermostat so it is 
exposed to cold air infiltration, drafts from windows or doors, air 
currents from supply or return air registers, behind obstructions, 
on a shelf, in a closet, or in a corner. 

Ensure that the thermostat will not be exposed to heat from a 
nearby fireplace, radio, television, lamp or rays from the sun. Do 
not mount the thermostat on a wall over a supply or return duct, 
chimney or vent. 

WARNING 

Wire thermostat to the vent terminal pressure switch and to the 
furnace electrical box (refer to wiring diagram). Set thermostat 
anticipator as shown on wiring diagrams on pages 16 and 17. 
 
 

Connect power wiring 

All wiring must conform to: 

•

  National Electrical Code, ANSI/NFPA 70, latest edition and 

any additional national, state or local codes. 

•

  In Canada, CSA C22.1 Canadian Electrical Code Part One 

and any local codes. 

•

  Wiring must be N.E.C. Class 1. If original wire as supplied 

with furnace must be replaced, type 105° C wire or equivalent 
must be used. Supply wiring to furnace must be sized for the 
load required (see Section 12). 

•

Provide electrical ground at furnace as required by codes. 

Connect 120 VAC/60 Hertz, single phase separate electrical line 
from the main house panel to the power leads in the furnace 
electrical box as shown on wiring diagram, pages 12, 13, 14 and 
15. Provide a fused disconnect in the power wiring, following all 
local codes. 

Ensure the wire size and type are adequate for the electrical load 
(see Section 12 and furnace nameplate for value). 
 
 

Limit control 

The furnace is equipped with a fan switch/limit control. This 
control limits the air leaving the heat exchanger to 200° F or less. 
The fan switch continues fan operation until the air drops to a 
preset temperature. For most installations, set the blower ON 
setting at 110° F and blower OFF setting at 90° F. If a longer cool 
down period is desired, lower the OFF setting. 
 

WARNING 

WARNING 

15