Hydrolevel VXT-24 User Manual

Model VXT-24

Programmable
Water Feeder for
Steam Boilers

24 VAC Operating Voltage

atent Pending

P

SPECIFICATIONS

MAXIMUM FLUID
TEMPERATURE: 150°F

AMBIENT TEMPERATURE: 100°F
FLOW RATE: 1 GPM
MAXIMUM FEED: 10 Gallons (2 Cycles)
ELECTRICAL: 24 VAC, 60 HZ

UNIVERSAL COMPATIBILITY: The VXT feeder can be used with virtually

•
any probe or float-type low water cut-off.

• FEED COUNTER: Brightly illuminated feed cycle counter displays the

mount of water added to the boiler – essential in diagnosing water loss

a
problems that can severely shorten the life of a steam boiler. Built-in mem­ory prevents power interruptions from clearing the counter.

• PROGRAMMABLE FEED DELAY SETTINGS: Helps prevent flooded boilers.
Allows time for condensate to return to the boiler before starting feed
cycle – ensuring that additional water is needed.

• PROGRAMMABLE FEED AMOUNT SETTINGS: Six settings provide two
ways to feed: 1-5 gallon settings feed above the Low Water Cut-Off to
restore boiler’s normal operating level. Or, select LWCO setting to end the
feed cycle when the Low Water Cut-Off re-energizes the burner.

• UNDERFEED PROTECTION: If one feed cycle is not sufficient to restore
boiler operation, the VXT will delay and feed one additional cycle.

• LOCKOUT FLOOD PROTECTION: The VXT locks-out to prevent steam sys­tem flooding and costly water damage if burner operation does not
resume after two

consecutive feed cycles.

INSTALLATION

Step 1 Warning Step 2 Plumbing

WARNING – To
prevent electrical
shock or equipment
damage, power
must be off during
installation or ser­vicing of the con-

serious burns, the boiler should be thoroughly cooled
before installing or servicing control. Only qualified
personnel may install or service the control in accor­dance with local codes and ordinances. Read instruc­tions completely before proceeding.

We warrant products manufactured by Hydrolevel Company to
be free from defects in material and workmanship for a period
of two years from the date of manufacture or one year from
the date of installation, whichever occurs first. In the event of
any claim under this warranty or otherwise with respect to our
products which is made within such period, we will, at our
option, repair or replace such products or refund the purchase
price paid to us by you for such products. In no event shall

trol. To prevent

Feeder must be installed with a manual by-pass. Use isolation valves and
unions to allow easy removal for service or replacement. Remove and
clean the feed valve strainer after the first feed cycle to remove any conta­minents introduced during installation.

Note: Arrow on VXT valve indicates direction of water flow.

LIMITED MANUFACTURERʼS WARRANTY

Hydrolevel Company be liable for any other loss or damage,
whether direct, indirect, incidental or consequential. This war­ranty is your EXCLUSIVE remedy and shall be IN PLACE OF
any other warranty or guarantee, express or implied, includ­ing, without limitation, any warranty of MERCHANTABILITY or
fitness for a particular purpose. This warranty may not be
assigned or transferred and any unauthorized transfer or
assignment thereof shall be void and of no force or effect.

P.O. Box 1847 • New Haven, CT 06508 • Phone: [phone] • FAX: [phone] • www.hydrolevel.com

Step 3 Wiring

elect the wiring diagram below that corresponds to the low water cut-off installed on the boiler. Consult boiler manufacturerʼs

S
instructions for proper burner terminal connections.

Hydrolevel

Safgard Model 400 / CycleGard CG400

STANDARD WIRING

Note: If there is no jumper installed on the low water cut-off

between 1 and P1, see ALTERNATE WIRING box.

Safgard Model OEM-24TD

STANDARD WIRING

Note: If there is no jumper installed on the low water cut-off

between 2 and P1, see ALTERNATE WIRING box.

IMPORTANT

o prevent over-

T

eeding and possible

f
flooding, when used

ith the OEM-24TD,

w

he VXT should be

t

et with a Feed

s

elay of 10 minutes

D
and a Feed Amount
of 1 to 5 gallons
(see step 5).
DO NOT USE LWCO
SETTING.

cDonnell & Miller

M

PS-800 Series – Newer Models

STANDARD WIRING

Note: If there is no jumper installed on the low water cut-off

between H and C, see ALTERNATE WIRING box.

PS-800 Series – Older Models

STANDARD WIRING

Note: If there is no jumper installed on the low water cut-off

between 1 and 3, see ALTERNATE WIRING box.

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:
minal on the cut-off.
burner circuit hot.
circuit common.

Connect a wire from the FEED terminal on the feeder to the A ter-



Safgard & CycleGard Models:

Connect a wire from terminal H on the feeder to the



Connect a wire from terminal N on the feeder to burner



Float Style Control

Using the burner circuit to power the feeder

Using a separate power source for the feeder

ALTERNATE WIRING

If there is no jumper installed between terminals H and C on the low water cut­off (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

Connect a wire from the FEED terminal on the feeder to the W (4 on

used:



older models) terminal on the cut-off.
the feeder to the burner circuit hot.
feeder to burner circuit common.

PS-800 Series:

Connect a wire from terminal H on



Connect a wire from terminal N on the



Honeywell

Model RW-700 Guard Ring

Step 4 Set the Feed Delay

30-Second 2-Minute

(

Factory Setting)

4-Minute 6-Minute 8-Minute 10-Minute

NOTE: SELECT ONLY ONE DIPSWITCH CORRESPONDING TO THE DESIRED FEED DELAY.

he feed delay feature is designed to prevent boiler flooding by allowing time for condensate to return to the boiler prior to

T
feeding. 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.

Step 5 Set the Feed Amount

LWCO

(

Factory Setting)

NOTE: SELECT ONLY ONE DIPSWITCH CORRESPONDING TO THE DESIRED FEED AMOUNT.

CAUTION: BOILER FLOODING CAN OCCUR IF THE FEEDER IS NOT SET PROPERLY.

UNLIKE OTHER FEEDERS, THE 1-GALLON TO 5-GALLON SETTINGS WILL FEED THE FULL

CYCLE REGARDLESS OF WHEN THE WATER REACHES THE LOW WATER CUT-OFF.

LWCO Setting: The VXT feeder is shipped in the LWCO 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
boilerʼs
DO NOT USE LWCO SETTING WITH SAFGARD MODEL OEM-24TD.

normal

operating level, the 1-Gallon to 5-Gallon settings should be selected using the instructions below.

1-Gallon 2-Gallon 3-Gallon 4-Gallon 5-Gallon

minimum

requirements. If additional water is needed to reach the

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 LWCO 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

normal

water to reach the

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.

Step 6 Attach Service Tag

Complete the information at the top of the service tag provided and attach tag near the VXT Water Feeder.

Feed Counter

The VXTʼs built-in feed counter records the number of gallons that enter the boiler during automatic feed cyclesorif 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 (DISPLAY RST) button is located in the bot-

om right corner of the circuit board.

t

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. Lime 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-

itions and boiler design can impact the amount of water that can safe-

d
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 manufacturerʼs instructions carefully.

*The VXT Feeder is equipped with an orifice to regulate flow rates over a wide range of

ater pressures. The Feed Counter readings are designed to be accurate to ±15% with

w
water pressures between 20 to 90 PSI.

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 heat­ing season. They do not include water added as a result of boiler and/or low

ater cut-off maintenance.

w

Service / Maintenance

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.

Record and Reset Feed Counter: The feed counter should be checked annually. If the feed amount falls within the recom­mendations provided in the table above, record this amount on the card provided and press the reset button (DISPLAY 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.

Diagnostics / Trouble Shooting

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 LOC 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 manufacturerʼs 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 DELAY 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.

P.O. Box 1847 • New Haven, CT 06508 • Phone: [phone] • FAX: [phone] • www.hydrolevel.com