Weil-McLain SlimFit Guide

Part number 550-100-117/0714
Gas-fired water boilers
Commercial Condensing
TM
User’s
Information Manual
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.
Do not store or use gasoline or other flammable vapors and
liquids in the vicinity of this or any other appliance.
— WHAT TO DO IF YOU SMELL GAS —
• Do not try to light any appliance.
• Do not touch any electrical switch; do not use any telephone in your building.
• Immediately call your gas supplier from a neighbor’s telephone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
Installation & service must be performed by a
qualified installer, service technician or the gas supplier.

e following dened terms are used throughout this manual to bring aention to the presence of hazards of various risk levels or to
important information concerning the life of the product.
Indicates presence of hazards that will
cause severe personal injury, death or
substantial property damage.
Indicates presence of hazards that can
cause severe personal injury, death or
substantial property damage.
Indicates presence of hazards that will
or can cause minor personal injury or
property damage.
Indicates special instructions on
installation, operation or maintenance
that are important but not related to
personal injury or property damage.
e Boiler manual is for use only by a qualied 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 qualied
installer, service agency or the gas supplier (who must read and follow the
supplied instructions before installing, servicing, or removing this boiler.
is boiler contains materials that have been identied as carcinogenic, or
possibly carcinogenic, to humans).
When calling or writing
about the boiler— Please
have the boiler model num-
ber from the boiler rating
label and the CP number
from the label located on
the top of the boiler next
to the air inlet connection.
Hazard definitions
Boiler service and maintenance
How to use this manual . . .
To . . . Read/use . . . See pages . . .
Learn precautions Warnings and definitions 1 – 3
Start or shutdown the
boiler Use the OPERATING INSTRUCTIONS 4
Identify and locate boiler
components & the Sola
control display
These illustrations and callouts will show you the location of
main components and use of the Sola control display. 5 – 7
Prevent air contamination
Read the list of air contaminants you must avoid.
If found, either remove the products permanently, or have
your installer relocate boiler vent and air terminations to an
uncontaminated area.
8
Maintain the boiler
Maintain the boiler using the schedule in this manual.
Schedule an annual start-up by a qualified service
technician before every heating season.
9 – 12
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Failure to adhere to the guidelines on this page
can result in severe personal injury, death or sub-
stantial property damage.
Boiler service and maintenance —
❏To avoid electric shock, disconnect all electrical supplies to
the boiler before performing maintenance if wiring will be
exposed.
❏To avoid severe burns, allow boiler to cool before perform-
ing maintenance.
❏You must maintain the boiler as outlined in this manual
and have the boiler started up and serviced at least
annually by a qualied service technician to ensure boiler/
system reliability.
Boiler operation —
❏Do not block ow of combustion or ventilation air to boiler.
is boiler is equipped with a control which will automati-
cally shut down the boiler should air or vent be blocked.
If vent or air blockage is easily accessible and removable,
remove it. If the boiler display indicates a manual reset
lockout, follow the procedure on page7 to reset the boiler.
(If blockage is not obvious or cannot be removed, have the
boiler and system checked by a qualied service technician.)
❏Do not allow contaminated air to enter the boiler room (or
air inlet pipe if direct vented). See page8 for details.
❏Should overheating occur or gas supply fail to shut o, do
not turn o or disconnect electrical supply to boiler. Instead,
shut o the gas supply at a location external to the appliance.
❏Do not use this boiler if any part has been under water. Im-
mediately call a qualied service technician to inspect the
boiler and to replace any part of the control system and any
gas control, which has been under water.
Boiler water —
❏Have boiler water chemistry checked at least annually by a
qualied service technician.
❏DO NOT use petroleum-based cleaning or sealing com-
pounds in boiler system. Gaskets and seals in the system may
be damaged. is can result in substantial property damage.
❏DO NOT use “homemade cures” or “boiler patent medi-
cines”. Serious damage to boiler, personnel and/or property
may result.
❏Continual fresh makeup water will reduce boiler life. Mineral
build-up in boiler heat exchanger reduces heat transfer, over-
heats themetal, and causes heat exchanger failure. Addition of
oxygen can cause internal corrosion in system components.
Leaks in boiler or piping must be repaired at once to prevent
makeup water.
❏Do not add cold water to hot boiler. ermal shock can cause
boiler heat exchanger to crack.
STOP! READ THIS BEFORE PROCEEDING . . .
If any part of a boiler, burner or its controls
has been sprayed with or submerged under
water, either partially or fully, DO NOT attempt
to operate the boiler until the boiler has
been either replaced or completely repaired,
inspected, and you are sure that the boiler
and all components are in good condition
and fully reliable. Otherwise, by operating this
boiler, you will cause a re or explosion hazard,
and an electrical shock hazard, leading to serious
injury, death, or substantial property damage. See
the instructions at right.
Saltwater Damage — e exposure of boiler components to
saltwater can have both immediate and long-term eects. While the
immediate eects of saltwater damage are similar to those of fresh-
water (shorting out of electrical components, washing out of critical
lubricants, etc.), the salt and other contaminants le behind can lead
to longer term issues aer the water is gone due to the conductive
and corrosive nature of the salt residue. erefore, Weil-McLain
equipment contaminated with saltwater or polluted water will no
longer be covered under warranty and should be replaced.
Electrical Damage — If any electrical component or wiring
came into contact with water, or was suspected to have come into
contact with water, replace the boiler with a new Weil-McLain boiler.
Part number 550-100-117/0714 3
SlimFit™ commercial condensing gas-fired water boiler — User’s Manual

Figure 1 Operating instructions
OPERATING INSTRUCTIONS
External manual gas valve
Union
Drip leg
Boiler gas connection
From gas supply
External gas piping
(by installer)
See next page for location of interior
boiler manual gas valve.
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Figure 2 SlimFit boiler operating components
Figure 3 Boiler manual gas valve location, left-hand
boiler configuration, front-mounted display
(display may be in alternate location on the
burner end access panel)
Figure 4 Boiler manual gas valve location, right-hand
boiler configuration, front-mounted display
(display may be in alternate location on the
burner end access panel)
Boiler components
Boiler
manual
gas valve
Boiler
manual
gas valve
Switches
Reset switch (push to reset
boiler after a LOCKOUT)
Boiler ON/OFF switch
Low water cutoff reset switch (push
to reset after LWCO lockout)
Push to test low water cutoffSola touch-screen display — use
to monitor boiler operation, change
heating system setpoints, and enable/
disable burner.
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SlimFit™ commercial condensing gas-fired water boiler — User’s Manual

The Sola control touch-screen display
Press the boiler icon
on the home page to
go to the informa-
tion screen.
For technician
use only
For technician
use only
For technician
use only
Press to see event history.
e History bar will show the cause of a lockout
should one occur.
Use the Operation screen (le) to
• manually activate central heating or DHW.
• enable/disable the burner
• change normal and time of day setpoints for CH
Press Burner enable burner to enable/disable the
burner.
Press the Normal or Time of Day setpoint box to
change the water temperature seing.
DHW seings are factory set and are unchangeable.
Temperatures,
analog input and
ame signal
Operating
conditions (toggle
between Pumps,
Setpoints and
Modulation)
Annunciation
buon is for
technician
use only.
Use the Information screen and Operation screen to
monitor and manually operate the boiler.
Information screen
Operation screen
Make sure to return the boiler to
automatic operation aer using the
operation screen for manual opera-
tion. Failure to do so could cause loss
of heating.
ree information screens are accessible:
• Setpoints (shows current setpoints for CH,
DHW and Lead/lag)
• Pumps (shows status of pumps)
• Modulation (shows modulation conditions)
Use the buon labeled Pumps, Modulate or Set-
point to toggle between the views.
DO NOT OPERATE THIS BOILER unless it has been started up and
tested by a qualified service technician. Failure to comply could result
in severe personal injury, death or substantial property damage.
Part number 550-100-117/0714
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Resetting the Sola control after lockout
If resetting the boiler does not cor-
rect the condition, or if the condition
repeats, call you service technician
to inspect the boiler and correct the
problem.
SlimFit boiler lockout resolution
1. When a lockout occurs, the Sola control will enable the remote alarm
(if connected), sound its internal alarm (if enabled during setup by the
installer) and show the alarm condition on the display.
2. In an alarm condition, the home page boiler icon will turn red (see
Figure5).
3. From the home page (boiler on blue background), press the boiler icon
( ) to see the Information page.
a. e History bar will be red and will call out the reason for the
lockout.
b. For more detailed information, you can press the History bar to
see the History log.
4. To silence the alarm and reset the boiler from lockout, press the Control
reset buon on top of the boiler (not the low water cuto reset buon).
5. If the problem was a low water cuto lockout, you will also need to press
the Low water cuto Reset buon on top of the boiler.
Figure 5 Red Boiler icon on Home page
Figure 6 Red history bar on Status page
History Bar
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SlimFit™ commercial condensing gas-fired water boiler — User’s Manual

Prevent combustion air contamination
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.
Do not operate a SlimFit boiler if its combustion air inlet is located in a laundry room or pool facility, for example.
ese areas will always contain hazardous contaminants.
Pool and laundry products and common household and hobby products oen contain uorine or chlorine com-
pounds. When these chemicals pass through the boiler, they can form strong acids. e acid can eat through the
boiler wall, causing serious damage and presenting a possible threat of ue gas spillage or boiler water leakage into
the building.
Please read the information listed below. 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 Boiler
manual.
Products to avoid Areas likely to have contaminants
Spray cans containing chloro/fluorocarbons Dry cleaning/laundry areas and establishments
Permanent wave solutions Swimming pools
Chlorinated waxes/cleaners Metal fabrication plants
Chlorine-based swimming pool chemicals Beauty salons
Calcium chloride used for thawing Refrigeration repair shops
Sodium chloride used for water softening Photo processing plants
Refrigerant leaks Auto body shops
Paint or varnish removers Plastic manufacturing plants
Hydrochloric acid/muriatic acid Furniture refinishing areas and establishments
Cements and glues New building construction
Antistatic fabric softeners used in clothes dryers Remodeling areas
Chlorine-type bleaches, detergents, and cleaning
solvents found in household laundry rooms
Garages with workshops
Adhesives used to fasten building products and
other similar products
Part number 550-100-117/0714
SlimFit™ commercial condensing gas-fired water boiler — User’s Manual
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Annual startup and general maintenance
Figure 7 Service and maintenance schedules
OWNER MAINTENANCE (see the following pages for instructions)
BEGINNING OF SEASON
Contact your boiler service technician to inspect, service and start
up your boiler. You must have an annual start-up performed by a
qualified service technician to ensure reliable operation of the boiler
and system.
DAILY
Check boiler area
Check air openings
Check pressure/temperature gauge
MONTHLY
Check vent piping
Check air piping
Check relief valve
Check condensate drain system
Check automatic air vents (if used)
PERIODICALLY Test low water cutoff
EVERY
6 MONTHS
Check boiler piping (gas and water)
Operate relief valve
END
OF SEASON Shut boiler down (unless boiler used for domestic water)
Follow the service and maintenance procedures given throughout this manual and in component literature shipped
with the boiler. Failure to perform the service and maintenance could result in damage to the boiler or system. Failure to
follow the directions in this manual and component literature could result in severe personal injury, death or substantial
property damage.
The boiler must be serviced & maintained
e boiler must be inspected and started annually, at the beginning of the heating season, by a qualied
service technician.
In addition, the maintenance and care of the boiler listed on Figure7,page9 and explained in this
manual must be performed to assure maximum boiler eciency 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.
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SlimFit™ commercial condensing gas-fired water boiler — User’s Manual

Maintenance procedures — DAILY
DAILY MAINTENANCE
Check the boiler area
To prevent potential of severe personal injury, death or substantial
property damage, eliminate all materials discussed below
from the boiler vicinity and from the vicinity of boiler combustion
air inlet. If contaminants are found:
• Immediately remove products from the area. If they have been
there for an extended period, call a qualied service technician
to inspect the boiler for possible damage from acid corrosion.
• If products cannot be removed, immediately call a qualied
service technician to re-pipe vent (and air) piping and locate
vent termination/air intake away from contaminated areas.
Combustible/flammable
materials
Do not store combustible materials, gasoline or any other ammable
vapors or liquids near the boiler. Remove immediately if found.
Air contaminants
Products containing chlorine or uorine, if allowed to contaminate
the boiler intake air, will cause acidic condensate in the boiler. is
will cause signicant damage to the boiler if allowed to continue.
Read the list of potential materials listed on page8 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 the pressure/temperature gauge
1. Make sure the pressure reading on the boiler pressure/tempera-
ture gauge is no higher than the 5psig less than the relief valve
seing.
2. Contact a qualied service technician if pressure is too high.
DIRECT EXHAUST installations:
Verify combustion air openings are
clear and flue is unobstructed
1. DIRECT EXHAUST INSTALLATIONS (air supplied to the
boiler from inside)
a. Visually inspect all combustion air openings.
b. Remove any debris or blockage from combustion air louvers.
e combustion air openings must be unobstructed.
is is the means for combustion and ventilation air to
be drawn into the boiler room.
Failure to provide proper combustion air can result in
severe personal injury, death or substantial property
damage.
2. Verify that boiler vent discharge is clean and free of obstructions.
3. Remove any debris on the ue exhaust openings.
4. If removing the debris does not allow the boiler to operate cor-
rectly aerwards, contact your qualied service technician to
inspect the boiler and vent/air systems.
MONTHLY MAINTENANCE
Perform DAILY procedures plus the
following additional procedures . . .
Check vent piping
1. Visually inspect the ue gas vent piping for any signs of blockage,
leakage or deterioration of the piping. Notify your qualied service
technician at once if you nd any problem.
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
(DIRECT VENT installations)
1. Visually inspect the air inlet to be sure it is unobstructed. Inspect
entire length of air piping to ensure piping is intact and all joints
are properly sealed.
2. Call your qualied service technician if you notice any problems.
Check the 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 oen weeps, the expansion tank may not be
working properly. Immediately contact your qualied service
technician to inspect the boiler and system.
Check the condensate drain system
1. While the boiler is running, check the discharge end of the con-
densate drain piping. Make sure no ue gas is escaping from the
condensate drain tubing by holding your ngers in front of the
opening.
2. If you notice ue gas escaping, this indicates a dry condensate
drain trap. Call your qualied service technician to inspect the
boiler and condensate line and rell the condensate trap if problem
persists regularly.
Under some circumstances a SlimFit vent system
may not produce enough condensate to keep the
condensate trap full of liquid. If the trap is not full,
small amounts of ue products can be emied into the
boiler room through the condensate drain line or tee.
A qualified service technician must service the
boiler to properly refill the condensate trap.
Part number 550-100-117/0714
SlimFit™ commercial condensing gas-fired water boiler — User’s Manual
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Check automatic air vents (if used)
1. See illustration at right.
2. Remove the cap from any automatic air
vent in the system and check operation
by depressing valve “B” slightly with the
tip of a screwdriver.
3. If the air vent valve appears to be work-
ing freely and not leaking, replace cap
“A”, twisting all the way on.
4. Loosen cap “A” one turn to allow vent
to operate.
5. Have vent replaced if it does not operate
correctly.
PERIODIC MAINTENANCE
Perform DAILY procedures plus the
following additional procedures . . .
Test the low water cutoff
1. e boiler must be operating in central heating or DHW mode
for the following test to be performed.
2. Press the LWCO Test buon — Hold the Test buon until the
Sola control indicates a low water cuto lockout condition (a
few seconds).
3. e SlimFit boiler’s Sola control will shut down the boiler on
manual reset.
4. See page7 for information on Sola lockout behavior.
5. Press the LWCO Reset buon on top of the boiler to reset the
low water cuto.
6. Press the Control reset buon on top of the boiler (see Figure8)
to reset the Sola control.
7. e boiler should return to normal operation.
If the low water cuto fails to cause a manual reset
lockout condition, immediately turn o all power to
the boiler and contact your boiler technician.
EVERY 6 MONTHS MAINTEN.
Perform DAILY and MONTHLY
procedures plus the following additional
procedures . . .
Check the boiler water and gas piping
1. Perform gas leak inspection per steps 1 through7 of the Operating
Instructions, Figure1,page4.
2. If gas odor or leak is detected, immediately shut down boiler fol-
lowing procedures in the Operating Instructions, Figure1,page4.
Call a qualied service technician.
3. Visually inspect for leaks around internal water piping. Also
inspect external water piping, pumps, relief valve and ings.
Immediately call a qualied service technician to repair any leaks.
Have leaks xed at once by a qualied service techni-
cian. Failure to comply could result in severe personal
injury, death or substantial property damage.
Operate the 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.
To avoid water damage or scalding due to valve opera-
tion, a metal discharge line must be connected to relief
valve outlet and run to a safe place of disposal. is
discharge line must be installed by a qualied heating
installer or service technician in accordance with the in-
structions in the SlimFit Boiler Manual. e 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 sys-
tem is pressurized. Li the relief valve top lever slightly, allowing
water to relieve through the valve and discharge piping.
3. If water ows freely, release the lever and allow the valve to seat.
Watch the end of the relief valve discharge pipe to ensure that
Maintenance procedures — MONTHLY
Figure 8 Low water cutoff test and reset buttons
Low water cutoff reset switch (push
to reset after LWCO lockout)
Push to test low water cutoff
Part number 550-100-117/0714 11
SlimFit™ commercial condensing gas-fired water boiler — User’s Manual

Maintenance procedures — END OF SEASON
the valve does not weep aer the line has had time to drain. If the
valve weeps, li the seat again to aempt to clean the valve seat.
If the valve continues to weep aerwards, contact your qualied
service technician to inspect the valve and system.
4. If water does not ow from the valve when you li the lever
completely, the valve or discharge line may be blocked. Immedi-
ately shut down the boiler, following the operating instructions
on page9. Call your qualied service technician to inspect the
boiler and system.
END OF SEASON MAINTENANCE
To continue operation for DHW
1. If the boiler is to supply heat for domestic hot water generation
during the summer, no changes should be needed. Just leave the
boiler power on and allow the DHW storage tank to call for heat
as necessary.
2. Set back room thermostats to prevent any unnecessary call for
heat during the o season.
To leave boiler in stand-by mode
1. e SlimFit boiler’s Sola control provides eective features for
stand-by operation, including automatic operation to reduce
freeze possibilities. e Sola control must be setup as needed to
operate the necessary pumps.
2. Leave the boiler power on and allow the Sola control to monitor
the boiler and system during the stand-by period.
e Sola control must be congured to operate all
pumps needed to ensure the system and all circuits will
be protected against freezing. See the SlimFit Boiler
manual for details.
3. Set back room thermostats to prevent any unnecessary call for
heat during the o season.
To shut down the boiler
1. Follow “TO TURN OFF GAS TO APPLIANCE” of the Operat-
ing Instructions, Figure1,page4.
2. DO NOT drain the system unless exposure to freezing tempera-
tures will occur.
3. DO NOT drain the system if it is lled with an antifreeze solution.
4. DO NOT shut down boilers used for domestic water heating.
ey must operate year-round.
Part number 550-100-117/0714
SlimFit™ commercial condensing gas-fired water boiler — User’s Manual
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