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 (DISPLAY RST) but-
ton 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. Additionally, lime and sediment buildup resulting from excessive makeup water can impede heat transfer caus-
ing damage and/or premature failure of the boiler.
Recommended Limits on Makeup 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
safely be added to a steam boiler. As a general guideline for late
model boilers, Hydrolevel recommends the annual limits in the table
at the right for boiler operation. If feed amounts significantly exceed
these levels, the system should be checked for leaks by a qualified
technician.
Note:
Any makeup water 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.
Service / Maintenance
Water Damage Potential:
Failure to maintain the VXT Series feeder can result in excess mineral
deposits collecting in the valve. If left unchecked, these deposits can impede valve operation with the
potential for overfilling the heating system and allowing water to escape radiators into the living space.
The following maintenance must be performed by a qualified service technician:
Annually:
• Record the feed amount shown on the display on the VXT SERVICE TAG. Press the reset button (DISPLAY RST) on the bot-
tom right corner of the circuit board.
Note:
If the feed amount exceeds the limits in the table above, the system should be
checked for leaks.
• Remove and clean the strainer located on the valve body.
IMPORTANT:
If the strainer shows signs of mineral deposits collect-
ing on the screen, install a Hydrolevel Feed Valve Service Kit (Part No. 45-345).
Every 3 Years:
Install Hydrolevel Feed Valve Service Kit (Part No. 45-345).
Note:
If hardened calcium deposits have formed on
the brass surface inside the valve, replace the valve (Part no. 45-343).
12 Years:
Replace the VXT Series Water Feeder after 12 years of service.
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 regard-
less 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 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 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 makeup waterline is restricted. Check feed valve strainer for blockage or heavy buildup of debris.
Reset Feed Counter (see above) once problem is resolved.
126 Bailey Road • North Haven, CT 06473 • Phone: (203) 776-0473 • FAX: (203) 764-1711 •
www.hydrolevel.com
Recommended Makeup Water Limits
Net IBR Rating
Annual
BTU/HR
Limit
Up to 90,000
18
91,000 - 120,000
22
121,000 - 150,000
25
151,000 - 185,000
30
185,000 & Higher
35
Note:
Consult boiler manufacturer for limits that may differ from the above.
VXT24 0321
