Lochinvar KNIGHT 399 - 800 Guide

User’s Information Manual
Models: 399 - 800
If the information in this manual is not followed exactly, a fire or
explosion may result causing property damage, personal injury or
loss of life.
This appliance MUST NOT be installed in any location where
gasoline or flammable vapors are likely to be present.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do not use any phone in your
building.
• Immediately call your gas supplier from a near by phone.
Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
• Installation and service must be performed by a qualified
installer, service agency, or the gas supplier.
WARNING
Save this manual for future reference.
KBX-USER Rev F

2
Hazard definitions
The following defined terms are used throughout this manual to bring attention to the presence of hazards of various risk levels or
to important information concerning the life of the product.
DANGER
WARNING
CAUTION
CAUTION
NOTICE
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious
injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious
injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not
avoided, may result in property damage.
NOTICE indicates special instructions on installation, operation, or maintenance that are important but not
related to personal injury or property damage.
Contents
HAZARD DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . 2
PLEASE READ BEFORE PROCEEDING . . . . . . . . . . . . 3
1. PREVENT COMBUSTION AIR CONTAMINATION . . . 4
2. MAINTENANCE SCHEDULE . . . . . . . . . . . . . . . . . . . . 5
Maintenance Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Boiler Must Be Serviced and Maintained . . . . . . . . . . 6
Check Boiler Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Check Pressure Temperature Gauge . . . . . . . . . . . . . 6
Check Vent Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Check Air Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Check Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Check Condensate Drain System . . . . . . . . . . . . . . . . 6-7
Check Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Test Low Water Cutoff (if installed) . . . . . . . . . . . . . . . 8
Reset Button (low water cutoff) . . . . . . . . . . . . . . . . . . 8
Check Boiler Piping (gas and water) . . . . . . . . . . . . . . 8
Operate Relief Valve . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Shut Boiler Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. OPERATING INSTRUCTIONS . . . . . . . . . . . . . . . . . . . 9
4. SMART SYSTEM CONTROL MODULE
Knight XL Control Module . . . . . . . . . . . . . . . . . . . . . . . . 10
Access Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Saving Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Parameter Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
A: General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
B: Temperature Settings . . . . . . . . . . . . . . . . . . . . . . . 13
C: Data Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
E: DHW Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
F: Outdoor Air Reset . . . . . . . . . . . . . . . . . . . . . . . . . 14
Status Display Screens . . . . . . . . . . . . . . . . . . . . . . . . . . 15-18
NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Revision Notes . . . . . . . . . . . . . . . . . . . . . . . . . Back Cover

User’s Information Manual
Please read before proceeding
The Knight XL Installation and
Operation Manual along with the
Knight XL Service Manual are for use
only by a qualified heating
installer/service technician. Refer only
to this User’s Information Manual for
your reference. Improper installation,
adjustment, alteration, service or
maintenance can cause property
damage, personal injury (exposure to
hazardous materials) or loss of life.
Installation and service must be
performed by a qualified installer,
service agency or the gas supplier (who
must read and follow the supplied
instruction before installing, servicing,
or removing this boiler. This boiler
contains materials that have been
identified as carcinogenic, or possibly
carcinogenic, to humans).
Failure to adhere to the guidelines on
this page can result in severe personal
injury, death, or substantial property
damage.
Boiler service and maintenance –
• To avoid electric shock, disconnect electrical supply
before performing maintenance.
• To avoid severe burns, allow boiler to cool before
performing maintenance.
Boiler operation –
• Do not block flow of combustion or ventilation air to
the boiler. This boiler is equipped with a control which
will automatically shut down the boiler should air or
vent be blocked. If vent or air blockage is easily
accessible and removable, remove it. The boiler should
attempt to restart. If blockage is not obvious or cannot
be removed, have the boiler and system checked by a
qualified service technician.
• Should overheating occur or gas supply fail to shut off,
do not turn off or disconnect electrical supply to the
circulator. Instead, shut off the gas supply at a location
external to the appliance.
• Do not use this boiler if any part has been under water.
The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced.
Boiler water –
• Thoroughly flush the system (without boiler
connected) to remove sediment. The high-efficiency
heat exchanger can be damaged by build-up or
corrosion due to sediment.
• Do not use petroleum-based cleaning or sealing
compounds in the boiler system. Gaskets and seals in
the system may be damaged. This can result in
substantial property damage.
• Do not use “homemade cures” or “boiler patent
medicines”. Serious damage to the boiler, personnel,
and/or property may result.
• Continual fresh make-up water will reduce boiler life.
Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger,
and causes failure. Addition of oxygen carried in by
makeup water can cause internal corrosion. Leaks in
boiler or piping must be repaired at once to prevent
makeup water.
Freeze protection fluids –
• NEVER use automotive antifreeze. Use only inhibited
propylene glycol solutions, which are specifically
formulated for hydronic systems. Ethylene glycol is
toxic and can attack gaskets and seals used in hydronic
systems.
When calling or writing about the boiler
– Please have the boiler model and serial
number from the boiler rating plate.
Consider piping and installation when
determining boiler location.
Any claims for damage or shortage in
shipment must be filed immediately
against the transportation company by
the consignee.
Factory warranty (shipped with unit)
does not apply to units improperly
installed or improperly operated.
3
NOTICE
WARNING
NOTICE

User’s Information Manual
1 Prevent combustion air contamination
4
If the boiler combustion air inlet is located
in a laundry room or pool facility, for
example, these areas will always contain
hazardous contaminants.
To prevent the potential of severe personal
injury or death, check for areas and products
listed in Table 1A before installing the boiler
or air inlet piping.
If contaminants are found, you MUST:
• Remove contaminants permanently.
—OR—
• Relocate air inlet and vent
terminations to other areas.
WARNING
WARNING
Products to avoid:
Spray cans containing chloro/fluorocarbons
Permanent wave solutions
Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Refrigerant leaks
Paint or varnish removers
Hydrochloric acid/muriatic acid
Cements and glues
Antistatic fabric softeners used in clothes dryers
Chlorine-type bleaches, detergents, and cleaning solvents
found in household laundry rooms
Adhesives used to fasten building products and other
similar products
Areas likely to have contaminants
Dry cleaning/laundry areas and establishments
Swimming pools
Metal fabrication plants
Beauty shops
Refrigeration repair shops
Photo processing plants
Auto body shops
Plastic manufacturing plants
Furniture refinishing areas and establishments
New building construction
Remodeling areas
Garages with workshops
Table 1A Corrosive Contaminants and Sources
WARNING If the boiler combustion air inlet is located in
any area likely to cause contamination, or if
products which would contaminate the air
cannot be removed, you must have the
combustion air and vent re-piped and
terminated to another location.
Contaminated combustion air will damage
the boiler, resulting in possible severe
personal injury, death, or substantial
property damage.
Pool and laundry products and common household and hobby
products often contain fluorine or chlorine compounds. When
these chemicals pass through the boiler, they can form strong
acids. The acid can eat through the boiler wall, causing serious
damage and presenting a possible threat of flue gas spillage or
boiler water leakage into the building.
Please read the information listed in Table 1A. If contaminating
chemicals will be present near the location of the boiler
combustion air inlet, have your installer pipe the boiler
combustion air and vent to another location, per the Knight XL
Installation and Operation Manual.

User’s Information Manual
2 Maintenance schedule
5
WARNING Follow the maintenance procedures given throughout this manual. Failure to perform the service and
maintenance or follow the directions in this manual could result in damage to the boiler or system,
resulting in severe personal injury, death, or substantial property damage.
Service technician
(see the Knight XL Service Manual)
General:
• Address reported problems
• Inspect interior; clean and vacuum if
necessary;
• Clean condensate trap and fill with fresh
water
• Check for leaks (water, gas, flue,
condensate)
• Verify flue and air lines in good condition
and sealed tight
• Check system water pressure/system
piping/expansion tank
• Check control settings
• Check ignition and flame sense
electrodes (sand off any deposits; clean
and reposition)
• Check wiring and connections
• Perform start-up checkout and
performance verification per Section 10
in the Knight XL Installation and
Operation Manual.
• Flame inspection (stable, uniform)
• Flame signal (at least 10 microamps at
high fire)
• Clean the heat exchanger if flue
temperature is more than 54°F (30°C)
above return water temperature.
If combustion or performance
indicate need:
• Clean heat exchanger
• Remove and clean burner using
compressed air only
• Clean the blower wheel
Owner maintenance
(see pages 6 - 8 for detailed instructions)
Daily
• Check boiler area
• Check pressure/temperature
gauge
Monthly
• Check vent piping
• Check air piping
• Check air and vent termination
screens
• Check relief valve
• Check condensate drain system
• Check air vents
Periodically • Test low water cutoff (if used)
• Reset button (low water cutoff)
Every
6 months
• Check boiler piping (gas and
water) for leaks
• Operate relief valve
End
of season
months
• Shut boiler down (unless boiler
used for domestic hot water)
ANNUAL START-UP

User’s Information Manual
6
2 Maintenance schedule
Maintenance procedures
Boiler must be serviced and maintained
WARNING The boiler must be inspected and started
annually at the beginning of the heating
season by a qualified service technician. In
addition, the maintenance and care of the
boiler designated on page 5 of this manual
and explained on pages 6 through 8 must be
performed to assure maximum boiler
efficiency and reliability. Failure to service
and maintain the boiler and system could
result in equipment failure, causing possible
severe personal injury, death, or substantial
property damage.
NOTICE The following information provides detailed
instructions for completing the maintenance
items listed in the maintenance schedule on
page 5. In addition to this maintenance, the
boiler must be serviced and started up at the
beginning of each heating season by a
qualified service technician.
Check boiler area
WARNING To prevent potential of severe personal
injury, death, or substantial property
damage, eliminate all materials discussed
below from the boiler vicinity and the
vicinity of the boiler combustion air inlet. If
contaminants are found:
Remove products immediately from the area.
If they have been there for an extended
period, call a qualified service technician to
inspect the boiler for possible damage from
acid corrosion.
If products cannot be removed, immediately
call a qualified service technician to re-pipe
vent and air piping and locate vent
termination/air intake away from
contaminated areas.
1. Combustible/flammable materials -- Do not store
combustible materials, gasoline or any other flammable
vapors or liquids near the boiler. Remove immediately if
found.
2. Air contaminants -- Products containing chlorine or
fluorine, if allowed to contaminate the boiler intake air,
will cause acidic condensate in the boiler. This will cause
significant damage to the boiler if allowed to continue.
Read the list of potential materials listed in Table 1A on
page 4 of this manual. If any of these products are in the
room from which the boiler takes its combustion air, they
must be removed immediately or the boiler combustion
air (and vent termination) must be relocated to another
area.
Check pressure/temperature gauge
1. Make sure the pressure reading on the boiler pressure/
temperature gauge does not exceed 24 psi (165.5 kPa).
Higher pressure may indicate a problem with the
expansion tank.
2. Contact a qualified service technician if problem persists.
Check vent piping
1. Visually inspect the flue gas vent piping for any signs of
blockage, leakage, or deterioration of the piping. Notify
your qualified service technician at once if you find any
problems.
WARNING Failure to inspect the vent system as noted
above and have it repaired by a qualified
service technician can result in vent system
failure, causing severe personal injury or
death.
Check air piping
1. Visually inspect the air inlet termination to be sure it is
unobstructed. Inspect the entire length of air piping to
ensure piping is intact and all joints are properly sealed.
2. Call your qualified service technician if you notice any
problems.
Check relief valve
1. Inspect the boiler relief valve and the relief valve
discharge pipe for signs of weeping or leakage.
2. If the relief valve often weeps, the expansion tank may
not be working properly. Immediately contact your
qualified service technician to inspect the boiler and
system.
Check condensate drain system
1. Inspect the condensate drain line, condensate PVC
fittings and condensate trap.
Fill condensate trap with water
1. Remove the PVC cap retaining screw from the PVC cap
(FIG. 2-1).
2. Remove the 2" PVC cap with the switch located at the top
of the trap (FIG. 2-1).

User’s Information Manual
2 Maintenance schedule (continued)
7
3. Fill with fresh water until the water begins to pour out
of the drain.
4. Replace the cap. Press the cap onto the trap until the
cap makes contact with the drain.
5. Replace the retaining screw.
WARNING The condensate trap (FIG. 2-1) must be
filled with water during all times of
boiler operation to avoid flue gas
emission from the condensate drain line.
Failure to fill the trap could result in
severe personal injury or death.
PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
TO FLOOR
DRAIN
2” PVC CAP WITH
BLOCKED DRAIN SWITCH
RETAINING
SCREW
CONDENSATE FROM
HEAT EXCHANGER
Figure 2-1 Condensate Trap
Condensate disposal
1. This boiler is a high efficiency appliance that produces
condensate.
2. The side of the boiler has a 1/2 inch PVC union for
connection of a 1/2 inch PVC pipe (FIG. 2-2).
3. Slope condensate tubing down and away from the
boiler into a drain or condensate neutralizing filter.
Condensate from the Knight XL will be slightly acidic
(typically with a pH from 3 to 5). Install a neutralizing
filter if required by local codes. Call your qualified
service technician to inspect the boiler and system.
A Neutralizer Kit is available from the factory
(Kit 3087 for Models 399 - 500 and Kit 30002 for
Models 600 - 800). Call your qualified service
technician to install.
4. Install the 1/2 inch PVC tee assembly (shipped with the
unit) as shown in FIG. 2-2. Call your qualified service
technician to inspect the boiler and system.
5. Leave the top of the 1/2 inch tee OPEN. This is needed
as a vacuum break.
6. Do not expose condensate line to freezing temperatures.
7. Use only plastic tubing or piping as a condensate drain
line (FIG. 2-2).
Use materials approved by the authority
having jurisdiction. In the absence of
other authority, PVC and CPVC pipe must
comply with ASTM D1785 or D2845.
Cement and primer must comply with
ASME D2564 or F493. For Canada use
CSA or ULC certified PVC or CPVC pipe,
fittings, and cement.
8. A condensate removal pump is required if the boiler is
below the drain. When installing a condensate pump,
select one approved for use with condensing boilers and
furnaces. The pump should have an overflow switch to
prevent property damage from condensate spillage. Call
your qualified service technician to inspect
the boiler and system.
NOTICE
NOTICE To allow for proper drainage on large
horizontal runs, a second line vent may be
required and tubing size may need to
increase to 1 inch.
The condensate line must remain
unobstructed, allowing free flow of
condensate. If condensate is allowed to
freeze in the line or if the line is obstructed
in any other manner, condensate can exit
from the boiler tee, resulting in potential
water damage to property. Call your
qualified service technician to inspect
the boiler and system.
1/2" (12.7 mm) PVC UNION
(FACTORY SUPPLIED)
NEUTRALIZER KIT
FLOOR DRAIN OR
DRAIN PAN
1/2" (12.7 mm) PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
Figure 2-2 Condensate Disposal

User’s Information Manual
2 Maintenance schedule
8
WARNING Have leaks fixed at once by a qualified
service technician. Failure to comply could
result in severe personal injury, death, or
substantial property damage.
Operate relief valve
1. Before proceeding, verify that the relief valve outlet has
been piped to a safe place of discharge, avoiding any
possibility of scalding from hot water.
WARNING To avoid water damage or scalding due to
valve operation, a metal discharge line
must be connected to the relief valve outlet
and run to a safe place of disposal. This
discharge line must be installed by a
qualified heating installer or service
technician in accordance with the
instructions in the Knight XL Installation
and Operation Manual. The discharge line
must be terminated so as to eliminate
possibility of severe burns or property
damage should the valve discharge.
2. Read the boiler pressure/temperature gauge to make
sure the system is pressurized. Lift the relief valve
top lever slightly, allowing water to relieve through
the valve and discharge piping.
3. If water flows freely, release the lever and allow the valve
to seat. Watch the end of the relief valve discharge pipe
to ensure that the valve does not weep after the line has
had time to drain. If the valve weeps, lift the seat again to
attempt to clean the valve seat. If the valve continues to
weep afterwards, contact your qualified service
technician to inspect the valve and system.
4. If water does not flow from the valve when you lift the
lever completely, the valve or discharge line may be
blocked. Immediately shut down the boiler, following
the operating instructions on page 9 of this manual. Call
your qualified service technician to inspect the boiler and
system.
Shut boiler down (unless boiler is used
for Domestic Water)
1. Follow “To Turn Off Gas to Appliance” on page 9 of this
manual.
2. Do not drain the system unless exposure to freezing
temperatures will occur.
3. Do not drain the system if it is filled with an antifreeze
solution.
4. DO NOT shut down boilers used for domestic water
heating, they must operate year-round.
Check Air Vents
1. Reference FIG. 3 below.
2. Visually inspect vent to make sure that no leaks are present.
3. If there is leaking, tighten the needle valve.
4. If the leak continues, replace the air vent.
3. Replace the front access door.
Test low water cutoff (if installed)
1. If the system is equipped with a low water cutoff, test the
low water cutoff periodically during the heating season,
following the low water cutoff manufacturer’s
instructions.
Reset button (low water cutoff)
1. Testing the low water cutoff shuts the unit off. Press the
RESET button on the low water cutoff to turn the unit
back on.
Check boiler piping (gas and water)
1. Remove the boiler front access door and perform a gas
leak inspection per steps 1 through 7 of the Operating
Instructions on page 9. If gas odor or leak is detected,
immediately shut down the boiler following the procedure
on page 9. Call a qualified service technician.
2. Visually inspect for leaks around water piping.
Also inspect the circulators, relief valve, and fittings.
Immediately call a qualified service technician to repair
any leaks.
NEEDLE
VALVE
Figure 2-3 Air Vent

User’s Information Manual
9
3 Operating instructions
FOR YOUR SAFETY READ BEFORE OPERATING
WARNING: If you do not follow these instructions exactly, a fire or explosion
may result causing property damage, personal injury, or loss of life.
A. This appliance does not have a pilot. It is
equipped with an ignition device which
automatically lights the burner. Do not try
to light the burner by hand.
B. BEFORE OPERATING smell all around
the appliance area for gas. Be sure to
smell next to the floor because some gas
is heavier than air and will settle on the
floor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do
not use any phone in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.
C. Use only your hand to turn the gas control knob.
Never use tools. If the handle will not turn by
hand, don’t try to repair it, call a qualified service
technician. Force or attempted repair may result
in a fire or explosion.
D. Do not use this appliance if any part has been
under water. Immediately call a qualified
service technician to inspect the appliance and
to replace any part of the control system and
any gas control which has been under water.
• If you cannot reach your gas supplier, call
the fire department.
1. STOP! Read the safety information
above on this label.
2. Set the thermostat to lowest setting.
3. Turn off all electric power to the
appliance.
4. This appliance is equipped with an
ignition device which automatically lights
the burner. Do not try to light the burner
by hand.
5. Remove top cover.
6. Turn gas shutoff valve counterclockwise
to “OFF”. Handle will be perpendicular to
pipe. Do not force.
7. Wait five (5) minutes to clear out any gas.
If you then smell gas, STOP! Follow “B”
in the safety information above on this label.
If you don’t smell gas, go to next step.
8. Turn gas shutoff valve clockwise to “ON”.
Handle will be parallel to pipe.
9. Install top cover.
10. Turn on all electric power to appliance.
11. Set thermostat to desired setting.
12. If the appliance will not operate, follow the
instructions “To Turn Off Gas To Appliance” and
call your service technician or gas supplier.
1. Set the thermostat to lowest setting.
2. Turn off all electric power to the appliance
if service is to be performed.
3. Remove top cover.
4. Turn gas shut off valve counterclockwise to
“OFF”. Handle will be perpendicular to pipe.
Do not force.
5. Install top cover.
LBL2284 REV -
TO TURN OFF GAS TO APPLIANCE
OPERATING INSTRUCTIONS

User’s Information Manual
10
4 SMART SYSTEM control module
• Hold 5 seconds to enter code
Input Mode (Menu Mode)
• Press to move up one level
in Menu Mode or to exit
Menu Mode
• Press to turn boiler off or
back on
• Press to select a menu item
• Press after parameter programming
to store parameter data
• Press to exit Service Mode
• Press to toggle display during normal
operation to show outlet and return
temperatures, fan speed, and flame
signal
• Press to toggle between digits when
entering access code or between hour,
minutes, etc., when entering date and
time
• Press to change boiler water
temperature set point during
normal operation
• Press to change displayed data
values in Menu Mode
• Press to navigate through menu
listing in Menu Mode
DISPLAY SCREEN
MENU / EXIT
SHUTDOWN
ENTER / RESET
SERVICE
BUTTON
PC
CONNECTION
PORT
NEXT
PREVIOUS
DOWNUP
Figure 4-1 Control Panel
Knight XL control module
Use the control panel (FIG. 4-1) to set temperatures, operating conditions, and monitor boiler operation.