What is your shipping policy?

UPS ground is the default shipping method. Generally speaking, our goal is delivery within 3 business days or less. If necessary, we may upgrade your order to 3-day select or 2nd day air in an effort to reduce transit time.

Is there a remote monitoring option? I want to receive text and/or e-mail alerts.

While the HSRS does not currently provide remote monitoring capability, a cost-effective DIY solution is available. Receive instant alert texts and/or e-mails when HVAC shut-off occurs due to door/window violation. No monthly monitoring fees! Click here for details.

HSRS Wiring Installation

The HSRS is ideally suited for use with split (central / ducted) systems. We recommend installing the HSRS controller near the air handler, and routing a length of low-voltage wire into the HVAC unit for direct access to the 24vac power. (Most types of low voltage wire will suffice such as thermostat, telephone, intercom, or alarm wire.) For wiring details, including sample schematic click here.

Overhead doors & garage doors?

While HSRS door sensors are designed for residential doors & windows, there is nothing to preclude their use with other openings and door types. However, custom shims may be necessary for proper alignment of the sensor & magnet to ensure they are on the same plane.

For wired applications, you may optionally consider a specialty switch from a third party supplier. A few examples are listed below:

- Seco-Larm SM-226L

- Honeywell 958 Overhead Door Contacts

- Baomain Rotary Lever Sw. #WLCA12-2-Q

Note: Most any wired switch type can be used with the HSRS, as long as it is designed for normally-closed circuits.


Will it work with a smart thermostat?

Our HSRS is fully compatible for use with most conventional thermostats, including smart wi-fi models such as Nest and Ecobee. Keep in mind that when the HSRS shuts off the HVAC system (due to door or window violation), your thermostat may display an error indicating lost power. The error should clear once the HSRS restores normal operation.

What is the transmit range of wireless door sensors?

Signal range can be difficult to assess for a wireless device when applied indoors. This is because wireless signals can be adversely affected by a number of factors including interior walls, large appliances, RF interference, etc. Range specifications provided by the device manufacturer are typically measured under favorable conditions, typically in open air and with no obstructions. But actual usable range will be much lower and can vary from one installation to the next.

Our available wireless sensors are listed and compared below in terms of signal range.


Operating at 345 MHz, these sensors feature an open-air transmit range up to 200 ft (ideal conditions). However, you should presume a usable range of roughly 50 ft.


Our GEN2 classic sensor operates at 310 MHz and features a copper coil antenna, making it less susceptible to signal degradation issues. It has an open air transmit range of 100 ft., with an usable range of approximately 50 to 75 ft.

Comparison Chart:

The chart below compares transmit range for each product generation:

    GEN3   GEN2
  • Open air range : 200 ft.
  • Typical (usable):  50 ft.
  • Open air range : 100 ft.
  • Typical (usable): 50 to 75 ft



Will it work with a communicating thermostat?
(not to be confused with a conventional smart thermostat or wi-fi thermostat)

Our HSRS may be compatible with some communicating thermostats. To be clear, a "communicating thermostat" does not refer to a conventional smart thermostat (such as Nest or ecoBee). While conventional thermostats may possess smart features and even provide wi-fi user interfacing, they generally have no high level communications capability with the HVAC system, instead employing traditional low-voltage control wiring (Rc, Rh, C, Y, W, etc.)

Communicating thermostats interact with a control board located within the HVAC system. And unlike a conventional thermostat, it does not directly control the peripheral equipment. Rather, it sends data & command signals to the control board which, in turn, engages the equipment as necessary. Since a communicating thermostat operates through the transfer of data signals, it generally employs fewer wires or may even utilize a wireless interface such as Bluetooth. In some instances, the HVAC control board may provide typical wiring inputs for traditional HVAC control (Rc, Rh, C, Y, W, B, etc). If this is the case, you may the following options for applying our HSRS system:

  • Option 1: Condensate float switch: If the control board provides an input for a condensate float switch or similar shutoff limit, you may be able to wire our HSRS relay contacts to the specified inputs. (If a float switch or other normally-closed shutoff switch already exists, simply wire HSRS relay contacts in series with it.)
  • Option 2: Compressor/cooling wire: Break the "Y" wire (compressor / cooling) at the control board and connect to HSRS relay contacts.


  • HSRS relay contacts are: COM & N/C (terminals 12 & 13)
  • Do not attempt HSRS shutoff by disabling power to a communicating thermostat

Will a metal door interfere with wireless sensor operation?

Many types of metal doors, windows, and patio door frames can interfere with the operation of a wireless door sensor, severely undermining the RF signal. The sensor may operate flawlessly prior to installing the unit. But once mounted to the door or frame, there may be little, if any, detected signal at the controller / receiver.

Does the problem affect all wireless door sensors?

While most any wireless door sensor may be subject to this kind of impediment, our GEN2 "classic" sensor is designed with a copper coil antenna that makes it less susceptible, though not completely immune.

Is there a viable solution?

Fortunately, there is a relatively simple approach for combating the problem. Click here for details.

Which wireless system should I choose? (GEN2 vs GEN3)

Our HSRS wireless systems are available in two generations: GEN2 & GEN3. While both are functionally equivalent, there are some key differences to consider when making your purchase. (Bear in mind that the two generations are not cross-compatible. Therefore, you may not use a GEN2 sensor with a GEN3 controller, or vice-versa.) The two product generations are discussed below.

For a comparison summary, scroll to the bottom of the page.


Manufactured by Honeywell, these sensors are the same type found in compatible security systems. They feature sleek, modern design and long battery life (batteries included). We offer two GEN3 sensor models: mini and basic. Both operate at 345 MHz, and are advertised with a transmission range up to 200 ft. (open air). However, we have found the usable range is typically lower and can vary widely from one installation to the next. Therefore, you should presume a max range of 50 ft. GEN3 sensors store a factory-assigned ID (address) and need only be registered (i.e., paired) once at the controller/receiver. Long-life lithium battery is included, lasting 5 years or more.


Tried and true, our GEN2 classic (X10) sensor has withstood the test of time. Operating at 310 MHz and featuring internal copper-coil antenna, this device packs a wallop. Less susceptible to signal degradation issues, it yields an open air transmit range of 100 ft. (50 to 75 ft. typical). The sensor stores a random, self-assigned ID (address). Therefore, re-registration at the controller is required whenever batteries are replaced. Two (2) AAA alkaline batteries are required (not included), delivering up to 2 years of reliable operation. (Or use optional lithium cells for longer battery life!)

Comparison Chart:

The chart below compares critical features of the two wireless product generations:

    GEN3   GEN2
  • Modern design
  • Permanent ID (address)
  • Long-life lithium battery (included)
  • Copper coil antenna
  • Less susceptible to interference
  • Higher usable transmit range
  • Moderate range
  • Temporary ID (address)
  • Batteries not included

What is the current-switching capacity?

The Kadtronix family of smart relay systems are rated as follows:

  •   5A @ 125vac

Any tips for completing a proper install?

Installation is straightforward and requires no special skills other than your existing expertise with HVAC systems and basic wiring. Consider the following tips for a smooth, trouble-free installation:

Tip #1: When installing the HSRS wireless system, be careful to avoid contacting the antenna to any grounded surface such as the HVAC equipment chassis. For best RF reception, locate the antenna as high as possible (i.e., just below the ceiling). Also, ensure a minimum separation of 3 feet from any of the following:

  •   - Wireless devices (wi-fi routers, cordless phones, etc.)
  •   - Metal equipment (HVAC, laundry appliances, water heater, metal shelving, etc.)

Tip #2: If you are considering a wireless sensor to be used on a metal door, patio door, or other metal framed opening, apply masking tape to temporarily mount the sensor until confirming proper signalling with the controller/receiver. Consult the following resource for details:

Tip #3: When installing a wireless door/window sensor, consider the following:

  • - The mini sensor requires no setup other than inserting a CR2032 battery (included)
  • - The basic sensor contains two wiring screw terminals which must be wired together with a short jumper. Apply the jumper prior to inserting the battery. (The jumper can be omitted if you plan to apply a wired door switch at these wiring terminals.)
  • - The classic sensor must be properly initialized after inserting batteries. To do this, press & hold the white push-button for 5 seconds.

Tip #4: Before permanently mounting wireless door/window sensors, first complete the registration (i.e., pairing) procedure, keeping the sensors close at hand for convenience. Following registration, test to ensure the controller unit recognizes door sensor activity. Once you are satisfied the system is behaving properly, apply the sensors as desired.


Is it safe for my A/C compressor?

Absolutely. First, consider that modern HVAC systems are equipped with built-in delay mechanisms to ensure that refrigerant pressures have equalized before allowing the compressor to start. Second, our HSRS controller features its own configurable delays, described below:

Delay #1 minimizes the possibility of short-cycling by preventing shut-off unless the monitored door or window remains open for a preset time period. Configurable from 0 to 600 minutes (10 hours), the typical setting for most installations is 2 minutes. Therefore, a door must remain open continuously for 2 minutes before shut-off is invoked.

Delay #2 is a configurable re-activation timer that prevents the HVAC system from restarting until the desired time elapse. As mentioned earlier, most HVAC systems provide their own built-in delay for this purpose, so a secondary delay is typically not required. Still, we find that some customers prefer to deploy it for added peace of mind.