Hydrolevel Company HydroStat 3100 User manual

Does It All!
The Universal
Te perature Li it and
Low Water Cut-Off for
Oil and Gas Fired Boilers
䡵Replaces Cold Start and
Triple-Action Aq aStats*
• Install HydroStat on existing immersion well –
for full temperature functionality,
or
• Install HydroStat on an Electro-Well™– to add low water cut-off protection
䡵Simple dial-type temperat re and differential settings
䡵Easy to wire – ses the same terminal designations as common Aq astat®models.
䡵Dynamic Temperat re Display
䡵Fo r on-board diagnostic indicating lights
䡵Saves time, materials and wiring
atent ending *Aquastat is a registered trademark of Honeywell International, Inc.
Innovators in Boiler Protection
Since 1965
MODEL 3100
for gas-fired boilers
MODEL 3150
for oil-fired boilers

HydroStat®can be used in two ways.
By installing the control on an existing i ersion well,
HydroStat®can be used as a universal replace ent for
co on Aquastat®odels. Whether it’s a cold start or
a tankless coil boiler, Hydrostat®will provide all the
te perature functions of the control being replaced.
Or, install HydroStat®on a Hydrolevel Electro-Well™
(sold separately) to auto atically activate the low water
cut-off function. With HydroStat®you can add low water cut-off
protection to new or existing installations without the added ti e and
cost to install a separate control.
䡵Dial-Type Settings
Allows for quick and easy limit and differential settings.
䡵Dynamic Temperature Display
This 3-digit LED display continually indicates boiler temperature. Whenever the high limit,
low limit or differential temperature dials are turned, the LED instantly changes to display
the setting temperature. For a quick reference, the LED will scroll through the current
temperature and differential settings each time the HydroStat®control is powered up.
䡵Easy to Wire
HydroStat®uses the same terminal designations as common Aquastat®models. This makes field replacement
fast and easy.
䡵Four On-Board Diagnostic Indicating Lights
•TEM ACTIVE – Indicates HydroStat®is powered and the temperature
function is active.
•TEM HIGH TEMP – Illuminates any time the boiler is off on high
temperature limit.
•LWCO ACTIVE – Only illuminates when the HydroStat®is providing Low
Water Cut-Off functionality. This function is activated by installing the
control on a Hydrolevel Electro-Well™. This LED will not illuminate when
installed on a standard immersion well.
•LWCO LOW WATER – Indicates a low water condition in the boiler.
83 WATER STREET • NEW HAVEN, CONNECTICUT 06511
[phone] • FAX [phone] • TOLL FREE 800-654-0768 www.hydrolevel.com
Specificatio s
Model 3100 Model 3150
Input voltage 120 VAC, 60 HZ 120 VAC, 60 HZ
Burner contacts 30 VA@24 VAC 7.4 FLA, 44.4 LRA@120 VAC
Circulator contacts 5.8 FLA, 34.8 LRA@120 VAC 5.8 FLA, 34.8 LRA@120 VAC
Operating range – low limit Off or 110°F - 200°F Off or 110°F - 200°F
Operating range – high limit 100°F - 220°F 100°F - 220°F
Operating range – differential 10°F - 30°F 10°F - 30°F
Electro-Well™
To enable HydroStat’s®low water
cut-off function, Electro-Wells™
are available in four sizes
to replace
standard immersion wells.
Remote mounting kits are also
available.

1
83 Water Street • New Haven, CT 06511 • Phone [phone] • FAX [phone] • www.hydrole el.com
MODEL 3 50
Combination Low Water
Cut-Off & Uni ersal
Temperature Limit Control
120 VAC Operating Voltage
PATENT PENDING
WARNING Ele tri al sho k hazard. To prevent electrical shock, death or
equipment damage, disconnect power supply before
installing or servicing control. Only qualified personnel may install or service this control in
accordance with local codes and ordinances. Read instructions completely before proceeding.
CAUTION To prevent serious
burns, boiler
should be thoroughly cooled before installing or
servicing control.
• Dual Fun tion Design – HydroStat performs both high temperature limit and low
water cut-off functions when installed with a Hydrolevel Electro-Well™.
•Repla es Common Aquastat*Models – Can be installed on existing immersion
wells to replace both cold-start and triple-action Aquastats®. Industry standard
wiring designations make change-outs quick and easy.
• Digital Display – Easy to read LED continually displays boiler temperature. Also
displays temperature limit and differential settings during adjustment.
• Easy to Set – Dials for setting temperature limits and differentials eliminate
complicated programming.
•Advan ed Mi ro-Controller Design – Utilizes dual thermistor technology for
better accuracy, response and reliability.
•*Aquastat is a registered trademark of Honeywell International, Inc.
HydroStat installed
with Electro-Well™
When installed with the Hydrolevel Electro-Well,
HydroStat will provide both temperature and low water
cut-off functionality. If the control was supplied by the
boiler manufacturer, it was installed with an Electro-
Well. The Electro-Well is available separately for field
installations. See Electro-Well models on page 8.
OR
IMPORTANT When installed on a standard immersion well, HydroStat will not provide low water ut-off fun tionality.
HydroStat installed with
a standard immersion well
For field replacement of common Aquastat®models,
HydroStat can be installed with the immersion well
already on the boiler. In this configuration, HydroStat
will provide the temperature functionality of the control
being replaced, but will not provide low water cut-off
functionality. The “ WCO Active” ED will not illuminate.

2
MOUNTING THE CONTROL
STEP Two mounting positions are available on the
back of the control (Fig. 1). Select which of the two positions
(2 knockouts) is best for the location of the control. Remove
the knockout.
STEP 2 Place control on the well. While holding box
against well nut, tighten well clamp screw. (Fig. 2)
BACK OF HYDROSTAT BOX
FIG. 1
FIG. 3
FIG. 2
NOTE: In the case of space restrictions, the HydroStat con-
trol may be mounted in a horizontal orientation without any
loss of function. Hydrolevel recommends vertical mounting,
when possible, for proper orientation of ED display.
STEP 3 Insert sensor A THE WAY into well through
the knockout (A or B) you have chosen. (Fig. 3)
IMPORTANT Make sure that the immersion well or Electro-Well™ is installed on the boiler manufacturerʼs
designated temperature limit control tapping. Note: If installing an Electro-Well, pipe sealing compound should be
used. Teflon tape is not recommended.
REMOTE MOUNTING
The following kits are available separately for mounting
the HydroStat control box in a remote location. Each kit
includes mounting hardware and a remote sensor.
Part No. Description
48-101 HydroStat Remote Mount Kit
with 24" sensor
48-102 HydroStat Remote Mount Kit
with 48" sensor

WIRING
STEP Connect 120 VAC Hot to
terminal L1. Connect 120 VAC Neutral
to terminal L2. Disconnect means and
overload protection as required (pro-
vided by others).
STEP 2 Connect the circulator to
C1 and C2. (C2 is neutral.)
STEP 3 Connect the burner cir-
cuit to B1 and B2. (B2 is neutral.)
STEP 4 Connect the thermostat to
Tand T.
Multi-Zones Adding additional zones.
SCHEMATIC/LADDER DIAGRAM
WARNING Ele tri al sho k hazard. To prevent electrical shock, death or equipment damage, disconnect power supply before
installing or servicing this control.
3

4
SETTING THE CONTROL
To set COLD START operation
Operates on call for heat only.
Low Temperature Limit
Make sure ow Temperature imit is turned fully counter-
clockwise (OFF position).
Low Temperature Differential
No change is required.
High Temperature Limit
(factory setting = 190°F)
Adjust setting until desired temperature is displayed.
High Temperature Differential
(factory setting = 10°F)
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.
To set WARM START operation
Maintains temperature for domestic hot water.
Low Temperature Limit
Adjust setting until desired temperature is displayed.
Low Temperature Differential
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.
High Temperature Limit
(factory setting = 190°F)
Adjust setting until desired temperature is displayed.
High Temperature Differential
(factory setting = 10°F)
Using a small screwdriver, adjust setting until desired differ-
ential is displayed.
WARM START
(maintains temperature for domestic hot water)
Low Limit Switch = ON
COLD START
Low Limit Switch = OFF
Example
High Limit = 180°
Differential = 10°
On a call for heat, the burner will
shut off at 180° and restart at
170° (180°-10°). The circulator
will run as long as there is a call
for heat.
High Temperature Limit
(Adjustable 100° to 220°F)
De-energizes burner at HIGH
LIMIT setting
High Temperature Limit
(Adjustable 100° to 220°F)
De-energizes burner at HIGH
LIMIT setting
High Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the HIGH
LIMIT DIFFERENTIAL set point
High Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the HIGH
LIMIT DIFFERENTIAL set point
Low Temperature Limit
(Adjustable 110° to 200°F)
De-energizes burner at LOW
LIMIT setting
Low Temperature
Differential
(Adjustable 10° to 30°F)
Re-energizes burner when
temperature falls to the LOW
LIMIT DIFFERENTIAL set point
Example
High Limit = 180°
Differential = 10°
On a call for heat, the burner will
shut off at 180° and restart at
170° (180°-10°). The circulator
will run as long as there is a call
for heat.
Example
Low Limit = 150°
Differential = 10°
When there is no call for heat,
the burner fires at 140°
(150°-10°) to maintain boiler
temperature. Burner shuts off
at 150°.
NOTE: To prioritize domestic hot
water the HydroStat control will
not allow the circulator to
operate at any time the
temperature is below the low
limit setting.
OPERATION
Dynamic
Display
Water Temperature
and Real Time
Verification of
Setting Adjustments.
All Settings are
Displayed Every
Time Control is
Powered Up
ow Temperature
imit Setting
(OFF or 110°-200°F)
Factory OFF
ow Temperature
Differential Setting
(10°-30°F)
Factory 10°F
High Temperature
imit Setting
(100°-220°F)
Factory 190°F
Diagnostic EDs
High Temperature
Differential Setting
(10°-30°F)
Factory 10°F




NOTE: Be careful not to select overlapping temperature settings.
For example: If the HIGH TEMPERATURE IMIT is set at
190°F with a HIGH TEMPERATURE DIFFERENTIA set at 20°F,
then the OW TEMPERATURE IMIT needs to be set at 170°F
(190°F - 20°F = 170°F) or below.
IMPO TANT: To prevent flue gas condensation and reduce fatigue
caused by thermal cycling on conventional (non-condensing) boilers,
both HIGH and OW IMIT set points should be 150°F or above
( imit Setting - Differential Setting ≥ 150°F). Boiler manufacturerʼs
temperature requirements supercede these recommendations.

5
TROUBLESHOOTING
Burner Will Not Fire See Flow Chart 1, page 6
Burner Will Not Shut Down See Flow Chart 2, page 7
Temperature Display Exceeds
High Limit Setting
Under normal operation, boiler temperature will continue to rise after the control shuts off
the burner. This condition, known as “thermal stacking”, results from hot boiler surfaces
continuing to release heat into the boiler water.
No Domestic Hot Water
Make sure the low limit setting on the HydroStat is set properly. NOTE: If the low limit
setting is dialed fully counter clockwise, it will shut off the low temperature maintenance
feature and will function as a cold start control. If boiler is operating in conjunction with
an indirect water heater, check to be sure the temperature control on the indirect tank is
set properly. Make sure any valves in between domestic hot water heating device, boiler,
and hot water taps are open.
Boiler Will Not Maintain
Low Limit Temperature
Check for overlapping high temperature setting. If the high limit setting is set below the
low limit setting, the control will default to the high limit setting and the corresponding
high limit differential setting.
Temperature Display
Differs from Boiler
T&P Gauge Temperature
eading
Temperature variances can result from differing water temperatures within the boiler or
different reaction times of the two devices. If the HydroStat temperature is significantly
below the T&P gauge temperature, make sure the thermistor is inserted all the way to
the end of the well. If installed in an existing conventional well, check that hardened heat
conducting grease has not impeded the insertion of the thermistor. Clean or replace the
well to ensure proper insertion of the sensor.
LWCO “Active” Light
(Green LED) Is Not On
The HydroStat will only provide low water cut-off functionality when used in conjunction
with an insulated Electro-Well™. When attached to a standard immersion well, the
WCO “Active” light will remain off and the HydroStat will provide temperature
functionality only.
Low Water Light
( ed LED) Is On
WA NING: A low water condition is a serious and potentially dangerous condition. Do
not attempt to add water to a hot boiler. Allow the boiler to fully cool before adding water.
1. If the heating system is filled with water, pull the sensor out of the well and inspect it.
Make sure that the metal clip on the sensor is intact. This metal clip must be in contact
with the inside of the copper well in order for the control to sense the presence of
water. Check that the well does not have excessive build-up of heat transfer grease
that may interfere with clip contacting the well.
2. Remove well and examine for excessive residue build-up. Clean and re-install.
LED LEGEND
 TEMP ACTIVE Indicates that the HydroStat control is
powered and that the temperature function is active.
 TEMP HIGH TEMP Illuminates when the boiler water
temperature reaches the high limit setting. It will remain lit
until the water temperature falls below the high limit setting
less the differential setting.
The HydroStat control will prevent burner operation while this
ED is on.
NOTE: This ED illuminates regularly during normal boiler
operation.
 WCO ACTIVE Indicates that the low water cut-off
( WCO) function of the HydroStat control is active. When the
control is installed with a Hydrolevel Electro-Well, this ED
will be on at all times when the control is powered.
NOTE: If the control was installed with a well other than the
Electro-Well, this ED will not illuminate. This indicates that
the control is providing temperature function only.
 WCO LOW WATE Indicates that the boiler is in a
low water condition. The HydroStat control will prevent burner
operation during this condition.
IMPO TANT:
The system must be checked by a qualified heating
professional prior to resuming operation.
WA NING: ALLOW THE BOILE TO FULLY COOL
BEFO E ADDING WATE .

6
NO
YES NO
Is the
Thermostat
(T-T) Calling
for Heat?
Is There
120 AC
Between B1
and B2?
NO
Is the
External Zone
(ZC-ZR) Calling
for Heat?
NO
Is the
Low Limit Dial
Set to OFF?
YES
NO
YES
Is the
Red LED
On?
The Control is
Sensing
Low Water.
CAUTION – ALWAYS ALLOW A BOILER TO COOL BEFORE ADDING WATER
The burner will not fire until the low water condition is satisfied.
Check that the system is filled with water.
Check that the sensor is inserted correctly into well.
Note: The use of heat-conductive grease may interfere with the
contact between the spring clip and the copper well tube.
Check that the control is tightly clamped to the well.
Is the
Yellow LED
On?
The Control is
Sensing High
Temperature.
If both the red and yellow LEDs are off and
there is a call to fire the burner, there will be
120 AC on terminals B1 and B2.
If 120 AC is not present, the control should
be replaced.
HydroStat is supplying 120 AC to the burner circuit.
Recheck wiring and operation of burner and other limit controls.
The Control
is Operating
Properly.
Replace
Control
The burner will not fire until the boiler water has dropped to the
high limit differential set-point. See HydroStat Settings chart.
Check that the high temperature setting is correct.
Troubleshooting Flow Chart 1 – Burner Will Not Fire
YES
YES
NO
Is the
Green LED
(TEMP ACTI E)
On?
The Control is
Not Powered.
The Temp Active LED will be on at all times when the control is
powered.
Check for 120 AC on terminals L1 and L2.
YES
NO
When the low temperature
setting is set to OFF, the
HydroStat will act as a cold
start control. The burner
will not fire unless there is
a call from the thermostat
(T-T) or an external zone
(ZC-ZR).
Set thermostat to call
for heat. Burner should
fire.
If the boiler has a tank-
less coil, set the Low
Temperature Limit to
maintain temperature.
YES

7
YES
Recheck
Wiring.
Replace
Control.
When there is no call to fire the burner, the voltage
should be 0 volts between B1 and B2.
 Make sure the burner is wired to B1.
YES
NO
Is the
Low Limit Dial
Set to OFF?
Is there
120 AC between
B1 and B2?
NO
Is the
Thermostat
(T-T) Calling
for Heat?
YES
YES
Is the
External Zone
(ZC-ZR) Calling
for Heat?
NO
NO
Is the
Red LED
On?
The Control is
Sensing
Low Water. WA NING!
TURN OFF POWER TO BURNER IMMEDIATELY!
CAUTION – ALWAYS ALLOW A BOILER TO FULLY COOL
BEFORE ADDING WATER.
Recheck wiring. Make sure that burner is wired to
B1. Burner should never fire when red or yellow
LED is lit.
Is the
Yellow LED
On?
The Control is
Sensing High
Temperature.
The Control is
Operating
Normally.
The Control is
Operating
Normally.
The burner will continue to fire when there is a call
from the thermostat or external zone.
 Check temperature display. When the Low Limit is
set, the HydroStat will fire the burner until the
temperature reaches the Low Limit Setting.
If there is no call for heat (from T-T, ZC-ZR or Low
Limit), there should be 0 AC between B1-B2.
 If there is voltage between B1-B2, the control
should be replaced.
Troubleshooting Flow Chart 2 – Burner Will Not Shut Down
YES
YES
NO
NO

8
83 Water Street • New Haven, CT 06511 • Phone [phone] • FAX [phone] • www.hydrole el.com
SPECIFICATIONS – HYDROSTAT MODEL 3 50
DIMENSIONS
LOW WATER CUT-OFF TEST PROCEDURE
ELECTRO-WELLS
LIMITED MANUFACTU E ʼS WA ANTY
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 pur-
chase price paid to us by you for such products. In no event shall Hydrolevel Company
be liable for any other loss or damage, whether direct, indirect, incidental or conse-
quential. This warranty is your EXCLUSI E 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.
Input voltage 120 VAC, 60 HZ
Burner contacts 7.4 F A, 44.4 RA@120 VAC
Circulator contacts 5.8 F A, 34.8 RA@120 VAC
HydroStatʼs low water cut-off function is active when the control is installed on a Hydrolevel Electro-Well. To test the low water cut-off function:
 Turn off power to the control.  Set the thermostat to call for heat.  Gently slide the sensor out of the well to simulate a low water condition.
 Re-energize power to the control. The red OW WATER light should come on and the burner should not fire.  Turn power off again and rein-
stall the sensor in the well.  Re-energize power to the control. The green WCO ACTIVE light should illuminate and the burner should fire.
MAINTENANCE
Remove the Electro-Well from the heating system every five years and clean any scale or sediment deposits from all parts that are exposed to
the boiler water. After cleaning, reinstall the well using pipe sealing compound. Teflon tape is not recommended.
Operating range – low limit Off or 110°F - 200°F
Operating range – high limit 100°F - 220°F
Operating range – differential 10°F - 30°F