Hydrolevel VXT-24 User manual

Programmable
Water Feeder for
Steam Bo lers
24 VAC Ope ating Voltage
U.S. Patent No. 6,688,329
INSTALLATION
Model VXT-24
WARNING – To
pr v nt l ctrical
shock or quipm nt
damag , pow r
must b off during
installation or s r-
vicing of th con-
trol. To pr v nt
s rious burns, th boil r should b thoroughly cool d
b for installing or s rvicing control. Only qualifi d
p rsonn l may install or s rvic th control in accor-
danc with local cod s and ordinanc s. R ad instruc-
tions compl t ly b for proc ding.
LIMITED MANUFACTURER’S WARRANTY
W warrant products manufactur d by Hydrol v l Company to
b fr from d f cts in mat rial and workmanship for a p riod
of two y ars from th dat of manufactur or on y ar from
th dat of installation, which v r occurs first. In th v nt of
any claim und r this warranty or oth rwis with r sp ct to our
products which is mad within such p riod, w will, at our
option, r pair or r plac such products or r fund th purchas
pric paid to us by you for such products. In no v nt shall
Hydrol v l Company b liabl for any oth r loss or damag ,
wh th r dir ct, indir ct, incid ntal or cons qu ntial. This war-
ranty is your EXCLUSIVE r m dy and shall b IN PLACE OF
any oth r warranty or guarant , xpr ss or impli d, includ-
ing, without limitation, any warranty of MERCHANTABILITY or
fitn ss for a particular purpos . This warranty may not b
assign d or transf rr d and any unauthoriz d transf r or
assignm nt th r of shall b void and of no forc or ff ct.
SPECIFICATIONS
MAXIMUM FLUID
TEMPERATURE: 150°F
AMBIENT TEMPERATURE: 100°F
FLOW RATE: 1 GPM
MAXIMUM FEED: 10 Gallons (2 Cycl s)
ELECTRICAL: 24 VAC, 60 HZ
1 6 Bailey Road • North Haven, CT 06473 • Phone: ( 03) 776-0473 • FAX: ( 03) 764-1711 • www.hydrolevel.com
• UNIVERSAL COMPATIBILITY: Th VXT f d r can b us d with virtually
any prob or float-typ low wat r cut-off.
• FEED COUNTER: Brightly illuminat d f d cycl count r displays th
amount of wat r add d to th boil r – ss ntial in diagnosing wat r loss
probl ms that can s v r ly short n th lif of a st am boil r. Built-in m m-
ory pr v nts pow r int rruptions from cl aring th count r.
• PROGRAMMABLE FEED DELAY SETTINGS: H lps pr v nt flood d boil rs.
Allows tim for cond nsat to r turn to th boil r b for starting f d
cycl – nsuring that additional wat r is n d d.
• PROGRAMMABLE FEED AMOUNT SETTINGS: Six s ttings provid two
ways to f d: 1-5 gallon s ttings f d above th Low Wat r Cut-Off to
r stor boil r’s normal op rating l v l. Or, s l ct LWCO s tting to nd th
f d cycl wh n th Low Wat r Cut-Off r - n rgiz s th burn r.
• UNDERFEED PROTECTION: If on f d cycl is not suffici nt to r stor
boil r op ration, th VXT will d lay and f d on additional cycl .
• LOCKOUT FLOOD PROTECTION: Th VXT locks-out to pr v nt st am sys-
t m flooding and costly wat r damag if burn r op ration do s not
r sum aft r two cons cutiv f d cycl s.
Step 1 Warn ng Step 2 Plumb ng
Feeder must be installed with a manual by-pass. Use isolation valves and
unions to allow easy removal for service or replacement. Arrows on VXT
valve indicates direction of water flow.
IMPORTANT: It is important to prevent any contaminants from entering
the feed valve during or any time after installation. The feeder should be
installed with non-ferrous plumbing materials only to prevent rust from
contaminating the valve. Apply pipe compound sparingly. Remove and
clean the feed valve strainer after the first feed cycle to remove any conta-
minants that could have been introduced during installation. See Service /
Maintenance on page 4 for additional information.

Step 3 W r ng Select the w r ng d agram through below that corresponds to the
low water cut-off nstalled on the bo ler.
Consult boiler manufacturer’s instructions for proper burner terminal connections.
Note: If there is no jumper installed on the low water cut-off
between 1 and P1, see ALTERNATE WIRING box.
Note: If there is no jumper installed on the low water cut-off
between H and C, see ALTERNATE WIRING box.
Note: If there is no jumper installed on the low water cut-off
between 2 and P1, see ALTERNATE WIRING box.
Note: If there is no jumper installed on the low water cut-off
between 1 and 3, see ALTERNATE WIRING box.
Hydrolevel McDonnell & M ller
Float Style Control Honeywell
PS-800 Ser es – Older Models
STANDARD WIRING
Safgard Model OEM-24TD
STANDARD WIRING IMPORTANT
To pr v nt ov r-f d-
ing and possibl
flooding, wh n us d
with th OEM-24TD,
th VXT should b s t
with a F d D lay of
10 minut s and a
F d Amount of 1 to 5
gallons (s st p 5).
DO NOT USE LWCO
SETTING.
ALTERNATE WIRING
Safgard & CycleGard Models:
If there is no jumper installed between terminals 1 and P1 on the low cut-off
(between 2 and P1 on Model OEM-24TD), then the cut-off is powered by a
separate power source from the burner circuit and the following wiring must
be used: ➀Connect a wire from the FEED terminal on the feeder to the A
terminal on the cut-off. ➁Connect a wire from terminal H on the feeder to
the burner circuit hot. ➂Connect a wire from terminal N on the feeder to
burner circuit common.
ALTERNATE WIRING
PS-800 Series:
If there is no jumper installed between terminals H and C on the low water
cut-off (terminals 1 and 3 on older models), then the cut-off is powered by a
separate power source from the burner circuit and the following wiring must
be used: ➀Connect a wire from the FEED terminal on the feeder to the W
(4 on older models) terminal on the cut-off. ➁Connect a wire from terminal
H on the feeder to the burner circuit hot. ➂Connect a wire from terminal N
on the feeder to burner circuit common.
Using a separate power source for the feeder
Model RW-700 Guard R ng
Using the burner circuit to power the feeder
Safgard Model 400 / CycleGard CG400
STANDARD WIRING PS-800 Ser es – Newer Models
STANDARD WIRING

30-Second 2-Minute
(Factory Setting)
4-Minute 6-Minute 8-Minute 10-Minute
The feed delay feature is designed to prevent boiler flooding by allowing time for condensate to return to the boiler prior to feed-
ing. If the returns and vents are in good condition, the 2-minute factory setting is usually sufficient. If for any reason condensate
takes longer to return to the boiler (such as old return lines or long horizontal runs), a longer delay setting should be selected.
NOTE: SELECT ONL ONE DIPSWITCH CORRESPONDING TO THE DESIRED FEED DELA .
WCO
(Factory Setting)
1-Gallon 2-Gallon 3-Gallon 4-Gallon 5-Gallon
LWCO Setting: The VXT feeder is shipped in the WCO feed setting. When operating in this setting, the VXT will feed only
until the low water cut-off re-energizes the burner circuit (or a maximum of 5 gallons). This will restore boiler operation, but on
some applications may only be enough water to satisfy the minimum requirements. If additional water is needed to reach the
boiler’s normal operating level, the 1-Gallon to 5-Gallon settings should be selected using the instructions below.
DO NOT USE WCO SETTING WITH SAFGARD MODE OEM-24TD.
1 Gallon to 5 Gallon Settings: When the 1 to 5 Gallon settings are used, the feeder will continue to feed until the cycle is
complete, regardless of when the low water cut-off is satisfied. These settings should be used only when the WCO setting
does not provide adequate water to restore the boiler to a normal operating level. Use the following instructions when choosing
these settings:
Boilers with probe-type cut-offs:
1. With power to the system on and the thermostat off, lower
the water level to approximately 1/2" below the probe.
2. Press the FEED button on the water feeder and, using a
watch with a second hand, time how long it takes boiler
water to reach the normal operating level (Usually the
middle of the gauge glass unless otherwise specified by
the boiler manufacturer).
3. Round the time to the nearest minute and set the feeder
for the corresponding number of gallons.
Example: If it takes 1 minute and 15 seconds for water to
rise from 1/2" below the probe to the normal operating
level, round to 1 minute and set the feeder for 1-Gallon.
4. Once the Feed Amount has been set, perform a test cycle
by lowering the water a second time (following procedures
in Step 1 above) and allowing the feeder to replenish the
water automatically.
Boilers with float-type cut-offs:
1. With power to the system on and the thermostat off, lower
the water level until 1/4" is visible in the gauge glass.
2. Press the FEED button on the water feeder and, using a
watch with a second hand, time how long it takes boiler
water to reach the normal operating level (Usually the
middle of the gauge glass unless otherwise specified by
the boiler manufacturer).
3. Round the time to the nearest minute and set the feeder
for the corresponding number of gallons.
Example: If it takes 2 minutes and 10 seconds for
water to rise from 1/4" in the gauge glass to the normal
operating level, round to 2 minutes and set the feeder for
2-Gallons.
4. Once the Feed Amount has been set, perform a test cycle
by lowering the water a second time (following procedures
in Step 1 above) and allowing the feeder to replenish the
water automatically.
NOTE: SELECT ONL ONE DIPSWITCH CORRESPONDING TO THE DESIRED FEED AMOUNT.
CAUTION: BOILER FLOODING CAN OCCUR IF THE FEEDER IS NOT SET PROPERL .
UNLIKE OTHER FEEDERS, THE 1-GALLON TO 5-GALLON SETTINGS WILL FEED THE FULL
C CLE REGARDLESS OF WHEN THE WATER REACHES THE LOW WATER CUT-OFF.
Step 4 Set the Feed Delay
Step 5 Set the Feed Amount
Step 6 Attach Serv ce Tag
Complete the information at the top of the service tag provided and attach tag near the VXT Water Feeder.

Feed Counter
The VXT’s built-in feed counter records the number of gallons that enter the boiler during automatic feed cycles or if the FEED
button is pressed.* To determine how much water has been added to the boiler since the last service, the counter should be
checked, recorded, and reset each time the boiler is serviced. The counter reset (DISP AY RST) button is located in the bottom
right corner of the circuit board.
The addition of water to a boiler raises the oxygen level and accumulates lime and other mineral deposits over time. Excessive
feed cycles, resulting from leaks in the system, can cause cast iron boilers to oxidize (rust) internally, significantly reducing the
life of the boiler. ime and sediment build-up can impede heat transfer causing damage and/or premature failure of the boiler.
Recommended Limits on Make-Up Water
Many factors, such as the water capacity of the boiler, feed water con-
ditions and boiler design can impact the amount of water that can safe-
ly be added to a steam boiler. As a general guideline for late model
boilers, Hydrolevel recommends the monthly limits in the table at the
right for boiler operation during the heating season. If feed amounts
significantly exceed these levels, the system should be checked for
leaks by a qualified technician. Note: Any feed limits provided by the
boiler manufacturer supercede Hydrolevel recommendations. Please
check the boiler manufacturer’s instructions carefully.
*The VXT Feeder is equipped with an orifice to regulate flow rates over a wide range of
water pressures. The Feed Counter readings are designed to be accurate to ±15% with
water pressures between 20 to 90 PSI.
Serv ce / Ma ntenance
Clean Strainer: The Feed Valve Strainer should be removed and cleaned annually.
Check Feeder Operation: Feeder operation should be checked annually during boiler servicing to ensure proper operation and
feed amount.
WARNING Water Damage Potential: In hard water installations, the strainer should be inspected during annual cleaning for
mineral build up. If significant, the solenoid valve (sold separately) should be replaced to ensure proper operation. Excess min-
eral build up can impede valve operation with the potential for overfilling the heating system and causing water damage in the
living space.
Record and Reset Feed Counter: The feed counter should be checked annually. If the feed amount falls within the recommen-
dations provided in the table above, record this amount on the card provided and press the reset button (DISP AY RST) on the
bottom right corner of the circuit board. Note: If the feed amount significantly exceeds the recommendations above, the system
should be checked for leaks by a qualified technician.
D agnost cs / Trouble Shoot ng
A small indicating light in the lower right hand corner of the digital feed counter illuminates whenever the low
water cut-off is calling for a feed. The light remains on for the duration of the call from the cut-off regardless of the
mode the feeder is in (delay, feed or lock-out). The light turns off when the cut-off is satisfied and stops
calling for a feed.
If OC appears in the digital counter, the safety lockout feature is activated. This feature engages only when the
feeder completes two consecutive feed cycles and the low water cut-off does not re-energized the burner. The
feeder can be reset by briefly interrupting power to the heating system. Important: The following trouble shooting
steps should be taken to determine the cause of the lockout condition before restoring normal operation.
1. If the boiler is overfilled, the low water cut-off is not functioning properly. Using the manufacturer’s instructions, check the low
water cut-off operation.
2. If the boiler is in low water:
a. Check boiler and return piping for leaks.
b. If no leaks are detected, check to determine if the flow of the feeder is restricted. Check isolation valves around feeder to
ensure they are fully opened. Remove and clean the Feed Valve Strainer.
c. Check the feeder setting to ensure that it is set to feed adequate water in the event of a low water condition.
If ERR appears in the digital counter, more than one or no delay or feed button has been selected. See Step 4
and Step 5 for DE AY and FEED setting instructions.
If the digital counter is flashing, the meter has “rolled over” (exceeded 999) representing an excessive feed
amount for most applications. Check the system thoroughly for leaks. If no leaks are found, check to determine
if the make-up waterline is restricted. Check feed valve strainer for blockage or heavy build-up of debris.
Reset Feed Counter (see above) once problem is resolved.
1 6 Bailey Road • North Haven, CT 06473 • Phone: ( 03) 776-0473 • FAX: ( 03) 764-1711 • www.hydrolevel.com
Recommended Make-Up Water Limits
Net IBR Rating Gal/month
BTU/HR Limit
Up to 90,000 6
91,000 - 120,000 8
121,000 - 150,000 10
151,000 - 185,000 12
185,000 & Higher 15
Note: The above limits are based on normal boiler operation during the heat-
ing season. They do not include water added as a result of boiler and/or low
water cut-off maintenance.
VXT24 0317