Start-up – Lochinvar KNIGHT 800 User Manual

Page 52

Installation & Operation Manual

Start-up

Final checks before starting the boiler

Read the Knight XL Service Manual to familiarize
yourself with SMART SYSTEM control module
operation. Read this manual, page 53 for proper steps to
start boiler.

Verify the boiler and system are full of water and all
system components are correctly set for operation.

Verify the preparation procedures of Section 10, pages 50
and 51 have been completed.

Fill the vent condensate trap with water (removing the
retaining screw in order to remove the 2 inch PVC cap
with the switch located at the top of the trap). Replace
the cap. Press the cap onto the trap until the cap makes
contact with the drain. Replace the retaining screw.

Verify electrical connections are correct and securely
attached.

Inspect vent piping and air piping for signs of
deterioration from corrosion, physical damage or
sagging. Verify air piping and vent piping are intact and
correctly installed per this manual.

Start the boiler

Read and follow the Operating instructions in FIG. 10-2,
page 53.

If boiler does not start correctly

Check for loose connections, blown fuse or service switch
off?

Is external limit control (if used) open? Is boiler water
temperature above 200°F (93°C)?

Is thermostat set below room temperature?

Is gas turned on at meter or boiler?

Is incoming gas pressure less than 4 inches w.c. (.99 kPa)?

If none of the above corrects the problem, refer to the
Troubleshooting Section of the Knight XL Service Manual.

Check system and boiler

Check water piping

Check system piping for leaks. If found, shut down the
boiler and repair immediately. (See WARNINGS on
pages 50 and 51 (startup) regarding failure to repair
leaks.)

Vent any remaining air from the system using manual
vents. Air in the system will interfere with circulation and
cause heat distribution problems and noise.

Check vent piping and air piping

Check for gastight seal at every connection, seam of air
piping, and vent piping.

Venting system must be sealed gastight to
prevent flue gas spillage and carbon
monoxide emissions, which will result in
severe personal injury or death.

Check gas piping

Check around the boiler for gas odor following the
procedure on page 41 of this manual (connecting gas
supply piping).

If you discover evidence of any gas leak,
shut down the boiler at once. Find the
leak source with a bubble test and repair
immediately. Do not start the boiler again
until corrected. Failure to comply could
result in severe personal injury, death, or
substantial property damage.

Propane boilers – verify conversion

Verify propane conversion has been completed per the
Propane Conversion instructions.

DO NOT adjust or attempt to measure
gas valve outlet pressure. The gas valve is
factory-set for the correct outlet pressure.
This setting is suitable for natural gas and
propane, requiring no field adjustment.
Attempting to alter or measure the gas
valve outlet pressure could result in
damage to the valve, causing potential
severe personal injury, death, or
substantial property damage.

Check flame and combustion

Turn the main power off to the boiler by placing the
“On/Off ” switch in the OFF position.

Remove the flue temperature sensor from the flue pipe
connection. NOTE: Combustion measurements will be
made at this point.

Turn the main power on to the boiler by placing the
“On/Off ” switch in the ON position.

ƽ WARNING

ƽ WARNING Knight XL boilers are typically shipped

ready to fire on natural gas. Check boiler
rating plate to determine which fuel the
boiler is set for. If set to natural gas, it may
be converted to LP by installing an orifice
or by making a gas valve adjustment (see
pages 13 and 14). In order to operate on
LP gas, an orifice MUST BE installed or a
gas valve adjustment MUST BE made.
Failure to comply could result in severe
personal injury, death, or substantial
property damage.