Temperature Control

Temperature

Control

Installation Instructions

and Operating Manual

The AcuTemp utilizes a microcontroller-based

design to control water temperature. An advanced

software algorithm closely monitors the rate of

tank temperature changes and controls the heating

source to minimize fluctuations in tank temperature

while optimizing fuel efficiency. The control features

adjustable temperature settings for both residential

and commercial temperature operating ranges.

WARNING

All work must be

performed by a

qualiﬁed and licensed professional in accordance with

all applicable codes and ordinances.

WARNING

Electrical shock

hazard. To prevent

electrical shock, death, or equipment damage, discon-

nect power supply before installing or servicing control.

NOTICE - Read these instructions completely before proceeding

with the installation. Retain these instructions for future reference.

RATINGS

DIMENSIONS

Input 24 VAC, 60 Hz

Power 2.4 VA

Output Dry contacts, 50 VA

@ 24 VAC, 60 Hz

Ambient temp 30°F - 140°F

Operating temp (user selected)

Model 2000 (Residential Setting): 60°F - 160°F default

Model 2000 (Commercial Setting): 60°F - 180°F

Other Models: 60°F to the number specified in the suffix of the

model number. (ex Model 2000-135 has an operating temp

range of 60°F - 135°F)

Differential Automatically controlled 5°F - 10°F

2-3/4"

3-17/32"

INSTALLING THE CONTROL

5 Remove the knockout and replace it with the

plastic bushing.

NOTE: For line voltage applications replace the

knockout with proper conduit in accordance with

all applicable codes and ordinances.

1 Locate the immersion well in the tank that is

designed for the temperature control.

2 Hold the AcuTemp control onto the well and

tighten the screw at the base of the control.

3 Slide the sensor into the well. NOTE: two

sensor diameters (3/8" & 1/4") are available to

accommodate different well sizes.

WARNING: The sensor must be fully inserted and fit snugly in the well for proper operation.

If a smaller sensor is used or the sensor is not fully inserted overheating and scalding could result.

4 Trim the sensor wire to the required length (if

needed). Plug the sensor wire into the sensor

input. The terminals are not polarity sensitive.

NOTE: Be sure the wires are fully inserted into the

sensor input.

3A Sensor and Well

(remote mounted control)

1. Insert the sensor all the way into the well.

2. Install the rubber well cap onto the sensor wire

and slide to cover the end of the well

DISPLAY

During normal operation the control will display the temperature set

point. If the control is calling for heat, the decimal point in the bottom

right of the display will light. When the tank temperature is satisfied,

the decimal will turn off.

Calling for Heat

WIRING THE CONTROL

1 Connect the 24 VAC power source to the

“24 VAC Input” terminals (24 VAC transformer

field supplied).

Connect 24 VAC hot to terminal AC2 and 24 VAC

common to AC1. Be sure the AC1 terminal is also

electrically connected to the tank/system ground.

2 Connect the “Output Contacts” to the zone or

boiler control’s domestic water input.

NOTE: The “Output Contacts” are isolated dry

contacts that close when the control calls for

heat.

REFER TO “WIRING THE CONTROL” BELOW OR YOUR TANK MANUAL FOR WIRING INSTRUCTIONS.

SETTING THE CONTROL

Push the setting dial to enter the Temperature Setting mode. When pressed,

the display will show ‘OFF’ or the current temperature setting. Turn the dial

to select the desired water temperature to be maintained in the water heater.

See Commercial/Residential (below) for available temperature ranges. The

display will return to the operating mode after five seconds of inactivity.

IMPORTANT: Temperature variations can exist within the water heater. The

value displayed on the control is the approximate temperature. A typical

starting adjustment point is 120°F. Test the water at the closest point of use

for final control adjustment.

DANGER: Scald Hazard – Exposure to 125°F or hotter water can cause

scalding injuries. A mixing valve should be installed on installations

where point of use water temperatures are 125°F or higher.

Temperature Differential The differential does not need to be set.

The AcuTemp’s advanced software algorithm determines the optimum

temperature to initiate heat calls.

Celsius / Fahrenheit To change from Fahrenheit to Celsius, push and hold the setting dial for 5

seconds. The current selection, “F” or “c” will blink on the LED display. Release and turn the setting dial to

the desired setting “F” or “c” then push the setting dial again to select it. NOTE: When the control is set for

Celsius, the display will include a “c” following the temperature. Once selected, the display will return to the

operating mode.

Residential / Commercial The control is equipped with two temperature ranges: One for

residential installations (60°F-160°F)* and a second for commercial installations (60°F-180°F). NOTE: Not

available on all models. To change from the Residential range to the Commercial range, remove power

from the control. Then push and hold the setting dial while restoring power. The current range, “r” or “c”

will blink in the LED display. Release and turn the setting dial to the desired range “r” or “c”, then push

the setting dial again to enter the setting. Once entered, the display will briefly show the selected setting;

then the control will display “off”. Follow the instructions above (Setting the Control) to set the desired

temperature within the selected (residential or commercial) range.

*Note: Some models have a max set point less than 160°F. See ratings section on page 1 for details.

Error Codes

Sensor Error The resistance value of the sensor is out of range. Check the sensor connection to

the pc board. If the connection is good, the sensor may need to be replaced.

--- Self Test Error The control has failed an internal test of the hardware or software. Try cycling

24 VAC power off and on. If the problem is resolved, the control will return to

normal operation. If the error does not clear, the control should be replaced.

Water temperature over 125°F (52°C) can

cause severe burns instantly resulting

in severe injury or death.

Children, the elderly, and the physically

or mentally disabled are at highest risk

for scald injury.

Feel water before bathing or showering.

Temperature limiting valves are available.

126 Bailey Road

North Haven, CT 06473

Phone (203) 776-0473 • FAX (203) 764-1711