Vapor Power HWR Series User manual

Page 1 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
Instruction Manual
HWR MODEL
‘RESISTO-FLO’
ELECTRIC BOILER

Page 2 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
FOREWORD
The HWR “Resisto-Flo” Electric Hot Water Boiler is designed to provide a
compact packaged unit requiring a minimum of electrical and plumbing
connections at the jobsite.
When installed according to these instructions, the boiler will provide years of
reliable, low maintenance service.
Review both the installation and electrical drawings thoroughly before installing
this boiler. A description of this boiler can be found in Bulletin 300, which is
included at the end of this text.

Page 3 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
1.0 INSTALLATION CLEARANCES
1.1 GENERAL
Locate boiler on a level surface. Be sure the location you select permits
access to the control cabinet and allows for element removal as dimensioned
on the installation drawing, and also that it is in accordance with the
minimum spacing specified on the UL label, if provided.
CAUTION
ALL BOILERS EXCEPT MODELS HWR 1638 THRU 1654 ARE TO BE MOUNTED
ON NONCOMBUSTIBLE FLOORING.
1.2 MECHANICAL CLEARANCES
The clearances shown below are required for perimeter servicing of the
boiler. Note: Front clearance to be 42” if opposing wall is conductive.
36"
F
R
O
N
T
18"
18"
MODELS HWR 1638
THRU HWR 1654
36"
24"
18"
MODELS HWR 3656
THRU HWR 3680
24"
36"
18"
18"
MODELS HWR 2438
THRU HWR 2462
18"
36"
24"
36"
MODELS HWR 4872
THRU HWR 4886
24"
F
R
O
N
T
F
R
O
N
T
F
R
O
N
T

Page 4 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
1.3 THERMAL CLEARANCES
Minimum thermal clearances should be maintained. If the boiler is UL listed,
minimum clearances will be indicated on the UL Label. Otherwise, consult
local codes and use good engineering judgment.
CAUTION
THE BOILER ROOM TEMPERATURE SHOULD NOT EXCEED 30º C (86ºF),
WHICH SHOULD LIMIT THE TEMPERATURE WITHIN THE CONTROL
CABINET TO A MAXIMUM OF 40ºC (104ºF).

Page 5 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
2.0 PLUMBING INSTALLATION
2.1 SUPPLY AND RETURN LINES
Connect supply piping to the water outlet at top of the boiler. The placement
of a temperature sensor in this line close to the boiler is recommended to later
monitor proper system operation.
Make the return connection to the water inlet at the rear of the boiler.
NOTE: IT IS RECOMMENDED THAT ALL PIPING BE CHECKED FOR LEAKS
BEFORE INSULATING.
NOTE: SYSTEM MAKE-UP WATER IS NORMALLY INTRODUCED AT OR NEAR
THE EXPANSION TANK.
2.2 SAFETY RELIEF VALVE(S)
An ASME-approved safety relief valve (required by the ASME code to
prevent system overpressure) is supplied with the boiler. This valve should
be factory set at or below maximum working pressure of the boiler as stated
on the boiler nameplate.
NOTE: THE SYSTEM OPERATING PRESSURE MAY BE LIMITED BY THE SYSTEM
COMPONENTS OTHER THAN THE BOILER, IT IS, THEREFORE
ADVISABLE TO CHECK THE SAFE WORKING PRESSURE OF ALL
COMPONENTS IN THE SYSTEM AND, IF NECESSARY, REPLACE THE
SAFETY VALVE WITH A VALVE SET AT A LOWER PRESSURE, BUT
SUFFICIENT CAPACITY (3500 x KW = BTU’s/HR REQ’D) TO ASSURE
COMPLETE SYSTEM PROTECTION.
The discharge outlet of the relief valve should be piped to within 6” of the
floor or to a safe point of discharge where no injury to persons could result
from an unexpected discharge of hot water from the valve.
2.3 EXPANSION TANK
An expansion tank must be provided to accommodate the increase in volume
of the water in the heating system when the water is heated. The expansion

Page 6 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
tank capacity should allow for increase in water volume of the heating
system, including the boiler, radiators or coils, and all piping.
2.4 LOW WATER CUTOFF
The boiler is as standard with a probe-type low water cutoff. If boiler is
supplied with a ball/float type low water cutoff, a blowdown valve should be
installed off the lower plugged cross to facilitate routine checking for proper
function of the cutoff control.
2.5 HYDRO TEST
Good practice, as well as, most local codes, dictates that a hydrostatic test, at
a pressure equal to the safety valve setting, of the entire boiler system be
performed prior to boiler start up. All leaks, both boiler and piping, should be
“stopped” at this time.
NOTE: SMALL LEAKS (LESS THAN 2 DROPS PER MINUTE) BETWEEN THE BODIES
OF THE ELEMNT COMPRESSION FITTING AND THE ELEMENT FLANGES
USUALLY STOP DURING THE FIRST FEW DAYS OF BOILER OPERATION.
LARGER LEAKS, HOWEVER MAY NECESSITATE TIGHTENING OF THE
COMPRESSION FITTING BODY. THIS IS ACCOMPLISHED BY FIRST
REMOVING THE ASSOCIATED WIRES/JUMPERS, AND THEN TIGHTENING
THE COMPRESSION BODY.
CAUTION:
DO NOT TORQUE BRASS COMPRESSION BODY OVER 70 FT LBS
NOTE: ALL PIPING, VALVES, AND FITTINGS MUST MEET THE REQUIREMENTS OF
LOCAL REGULATING CODES. THE RESPONSIBILITY FOR THE INSTALLA-
TION OF THIS BOILER RESTS WITH EITHER THE OWNER OR THE
INSTALLING CONTRACTOR.

Page 7 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
3.0 ELECTRICAL INSTALLATION
3.1 ELECTRIC POWER SUPPLY
Check the boiler nameplate for the KW rating, voltage, phase and ampacity.
Check for the electrical supply to be certain it conforms with the boiler
requirements.
Make electrical connections to main terminals housed within the top portion
of the boiler control cabinet. Minimum wire size is given both on the
electrical schematic and near the boiler terminals. On boilers, which require
multiple conductors per phase, be certain that phasing is correct and that
circuits are not “mixed” before energizing the boiler.
3.2 GROUNDING
Connect an equipment ground (minimum copper wire size is indicated on
both the wiring schematic and the panel near the grounding lug) to the
grounding lug located within the control cabinet.
NOTE: ELECTRICAL INSTALLATION MUST BE MADE IN STRICT ACCORD WITH (1)
THE BOILER’S ELECTRICAL SCHEMATIC, (2) THE NATIONAL ELECTRICAL
CODE, AND (3) LOCAL ELECTRICAL CODES.
3.3 CONTROL CIRCUIT POWER SUPPLY
On boilers, which are not supplied with 480/120V control transformer, a
fused 120-volt power supply must be connected to the 2-pole terminal block
housed within the top of the control cabinet. Refer to the boiler’s electrical
schematic for required ampacity.

Page 8 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
4.0 OPERATING INSTRUCTIONS
NOTE: PRIOR TO START UP, ANY HEATER OR CONTROL CABINET WHICH HAS
BEEN EXPOSED TO DUSTY, WET, AND/OR HUMID CONDITIONS MUST BE
THOROUGHLY CLEANED AND DRIED OUT. THE BUILD UP OF DUST
AND RUST MAY RESULT IN EXCESSIVE DAMAGE UNLESS THE
FOLLOWING PRECAUTIONS ARE UNDERTAKEN:
A. All electrical components should thoroughly cleaned and dried, and checked
for loose connections.
B. All electrical terminals should be thoroughly cleaned and dried, then hi-
potted or meggered to assure there are no shorts to ground.
C. Boiler should be inspected for stray objects, metal scraps, etc., which may
have accumulated during installation. All such materials must be removed
from the boiler prior to start up.
D. All power wiring connections should be checked to assure tight connections.
NOTE: HYDRO STEAM INDUSTRIES, AS MANUFACTURER OF THIS BOILER,
WILL NOT BE RESPONSIBLE FOR DAMAGES INCURRED AT THE TIME
BOILERS ARE STARTED UP UNLESS THE ABOVE STEPS HAVE BEEN
TAKEN TO ASSURE THE BOILERS ARE PROPERLY PREPARED FOR
STARTUP.
NOTE: MAXIMUM OPERATING CONDITIONS AS STATED ON THE BOILER
NAMEPLATE ARE NOT TO BE EXCEEDED
4.1 GENERAL
The following section of this manual should be read in its entirety prior to
operating the boiler.
4.2 PRELIMINARY CHECKS AND ADJUSTMENTS
4.2.1 TEMPERATURE CONTROL
(Boilers supplied with proportioning step controls)
A. Temperature Setting – Most Model HWR Boilers are provided with a
proportioning type temperature control system which regulates the boiler
output to match the system demand. This control should be set at the

Page 9 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
required operating temperature but shall not exceed 250°F. Proper system
operation can be checked via either the temperature gauge mounted on
the boiler’s supply piping or via the digital indication on the temperature
control..
B. Response/Range Adjustment - For boilers supplied with solid state step
controls. A “span” adjustment on the temperature control adjusts the
response/ differential of the control.
C. Interstage Time Delay – Most solid state step controls now include
adjustable interstage time delays. Some even include different delays for
steps-on and steps-off which can be adjusted to minimize contactor cycles
while still maintaining the required responsiveness of the control. Check
the vendor-supplied literature provided at the rear of this manual.
4.2.3 TEMPERATURE CONTROL
(Boilers supplied with one or more control thermostats)
Smaller HWR boilers are provided with one or more independent control
thermostats, which switch on or off heating elements in accordance with
their temperature setting. The differential between the thermostats should
be set in accordance with system requirements.
4.2.3 TEMPERATURE LIMIT THERMOSTATS
Check that that the auto and manual reset limits are set approximately 10%
and 15%, respectively, greater than the temperature control but not to
exceed 250°F.
4.2.4 Auxiliary Controls
Other controls supplied with the boiler (eg, KW limit controls, cycle or
delay timers, etc) should be set per the Engineer’s specifications.
NOTE: REFER TO DESCRIPTIVE LITERATURE IN THE REAR OF THIS
MANUAL ON THE RESPECTIVE AUXILIARY CONTROLS.

Page 10 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
4.3 BOILER START UP
A. Close drain valves.
B. Open all system flow valves (inlet and outlet).
C. Fill system with water. If a sight glass is provided, assure that it
indicates full.
WARNING
ENERGIZING THE HEATING ELEMENTS BEFORE COMPLETELY FILLING THE BOILER
WILL DAMAGE THE HEATING ELEMENTS, THUS VOIDING THE WARANTY. EVEN
THOUGH A LOW WATER CUTOFF IS PROVIDED WITH THE BOILER, THE BOILER
SHOULD NEVER BE SWITCHED ON WITHOUT FIRST ASSURING THAT THE BOILER IS
COMPLETELY FILLED.
4.3.1 Control Circuit Checkout
If a separate branch circuit is provided for the 120V control, close the
customer’s 120V branch circuit power switch; if a control circuit
transformer is provided, remove both the primary and secondary fuses and
jump a 120V power supply to the secondary of the control transformer.
A. Switch the control circuit power on, the switch should light to indicate
that the control circuit power is energized.
B. Circuits of heating elements will now be switched on by the step
controller or pressure controllers, and pilot lights will light indicating
that this function is taking place and, thus, that the controls are
operating correctly.
NOTE: IF A CONTACTOR “CHATTERS”, BLOW IT OUT WITH AIR AND THEN
CYCLE IT SEVERAL TIMES BY USING THE APPROPRIATE MANAUL
ENABLE TOGGLE SWITCH.
For boilers supplied with step controls, check the recycle feature by briefly
interrupting the control power – the step control should recycle and start in
a no- load condition. Perform maintenance checks of the control circuit
per paragraph 5.2

Page 11 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
Upon completion of the control circuit checkout, de-energize the control
circuit, remove the jumpers and replace fuses, if applicable, and switch all of
the circuit enable switches to the off position.
Energize the main power supply by closing the customer’s branch circuit
power switch.
Repeat steps A and B above to “start” the boiler.
Using the enable switches, gradually switch on the circuits.
Individually check each element circuit to assure that each leg is drawing its
rated current.
NOTE: SOME POWER FUSES MY BLOW AT STARTING DUE TO WATER OR OTHER
CONTAMINATION ON THE ELEMENT TERMINALS, SINCE THIS
CONTAMINATION USUALLY “BURNS” FREE, MERELY CHECK THE CIRCUIT
FOR A SHORT AND THEN REPLACE THE FUSE. IF A SHORT EXISTS,
HOWEVER, REPLACE THE DEFECTIVE ELEMENT PER PARGRAPH 5.3.3
4.4 BOILER SHUTDOWN
Switch the control circuit power off. For boilers supplied with step controls,
this will automatically recycle the step controller to no load so that when the
boiler is again switched on, no contactors will be initially energized.

Page 12 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
5.0 MAINTENANCE
5.1 BOILER
5.1.1 Pressure Vessel
Assure annual inspection by qualified ASME Boiler and Pressure Vessel
Inspector. This inspection will cover the vessel and relief valve only.
5.1.2 Heating Elements
Make periodic checks for loose terminal and wiring connections. If all
elements have been operating normally and all circuits draw rated current,
no element tests are required. If element failure is suspected, the elements
should be checked individually with an ohmmeter. Grounded elements
may require a “Megger” for detection.
5.2 CONTROL CIRCUITS
5.2.1 Temperature Limit Thermostats
Check cutout action of the limit thermostats by individually rotating the
dials to below the boiler water temperature. The step control should reset to
no load after each trip.
5.2.2 Low Water Cutoff
The LWCO level probe should be periodically checked. If there is any
seepage between the conductor and its insulator or between the insulator
and the compression fitting, replace the probe.
If the boiler is supplied with a float-type water cutoff, check the cutoff
action by periodically blowing down the water column as quickly as
possible. The step control should always reset to no load.
5.2.3 Temperature Control
A check of the proportioning temperature control system can be made by
moving the set point of the controller up or down scale and noting the
corresponding action of the step control. If the step control fails to follow
in either direction, refer to the appropriate descriptive literature at the rear
of this manual.

Page 13 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
5.2 MAJOR COMPONENTS
5.3.1 Contactors
Periodic inspection and cleaning of contact should be made. Spot check for
pitted, burned or welded contacts and inoperative coils. Discoloration of
the contacts and/or Bakelite is usually indicative of a failed or failing
contactor.
5.3.2 Fuses
Check for loose fuse clips and wires. Inspect for discoloration of clips due
to overheating.
5.3.3 Elements
The resistance type immersion elements are field replaceable with standard
tools. To replace defective elements, use the following procedure:
1. Turn off power to the boiler
2. Drain boiler below level of flange containing defective element.
3. Number and tag element wires and terminals to assure proper
reassembly
4. Disconnect element wires to the flange
5. Remove flange from boiler nozzle
6. Remove buss bars, #10-32 nuts, insulators and washers from the
defective element
7. Remove compression nut which holds the element in the flange
8. Slide element through flange (toward terminal side) far enough to cut
element off behind compression ferrule
9. Pull defective element back through flange
10. Clean the ferrule seat in the flange
11. Make certain replacement element is correct size. Check both the
voltage and KW rating stamped on the element itself
12. Slide new element through flange (from element bundle side), making
sure orientation is correct.
13. Install new compression fitting (ferrule) on element. Shorter end of

Page 14 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]
element should extend at least 1/8” beyond compression nut after
tightening (refer to element assembly sketch)
NOTE: TIGHTEN COMPRESSION FITTING TO 70 FT LBS Brass, 110 FT LBS SS MAX.
14. Reverse the procedure outlines in steps 4, 5 and 6 above using a new
gasket.
15. Refill boiler and purge air from system.
16. Check for leaks both before and after system is pressurized.
DETAIL - ELEMENT INSTALLATION
FERRULE
#10-32 NUT
COPPER BUSS
#10-32 NUT
FLAT WASHER (#10)
CERAMIC
RUBBER
ELEMENT FLANGE
ELEMENT
(TIGHTEN: 70 FT LBS MAX BRASS
110 FT LBS MAX S.S.)
TIGHTEN ENOUGH
TO
BULGE RUBBER
SEAT (IN
FLANGE)
5.4 CLEANING THE BOILER
Boiler should be drained and cleaned periodically to remove any accumulated
scale or sludge. This can normally be done at the time of annual inspection unless
experience indicated that more frequent cleaning is required.

Page 15 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]

Page 16 of 16
Vapor Power International LLC
551 S. County Line Road, Franklin Park, Il 60131
Phone: [phone] Fax: [phone]