Do I Need to Use End Of Line Resistors With the Qolsys IQ Hardwire 16-F?

Yes, you need to use end of line resistors with the Qolsys IQ Hardwire 16-F. This includes zones that do not have a sensor wired in and are not actively being used. Modules manufactured before week 40 of 2019 must use 4.7k resistors, which are color-coded Yellow-Violet-Black-Brown-Brown.

In order to properly enroll with a 319.5 MHz panel, all 16 zones on the Qolsys IQ Hardwire 16-F must have an end of line resistor wired in. The modules comes bundled with (16) 4.7k resistors for this exact purpose. Originally, this was the only resistor value you could use with the module. But in week 40 of 2019, Qolsys upgraded the module and made it support end of line resistor learning. This means that you can use resistor values ranging from 1k to 10k with Qolsys IQ Hardwire 16-F Converters manufactured in week 40 of 2019, as well as any units manufactured after that time. However, you must still have a compatible resistor wired at each zone, regardless of when the unit was manufactured. You can determine if your IQ Hardwire 16-F can support EOLR learning be checking its Serial Number (SN). More information is available here.

Qolsys IQ Hardwire 16-F units manufactured in week 40 of 2019 and beyond support two (2) modes. These are called Legacy Mode and UL Fire Mode. In Legacy Mode, at least one of the 16 zones on the Qolsys IQ Hardwire 16-F module will use an end of line resistor with a value of 1k to 10k (other than 4.7k). In UL Fire Mode, all of the zones will use 4.7k resistors. In order to be compliant with UL fire standards, the module must be in UL Fire Mode, and all zones must have a 4.7k resistor. Remember, Qolsys IQ Hardwire 16-F units built before week 40 of 2019 can only utilize UL Fire Mode. This means that each zone on the 16-F module will need a 4.7k resistor as a result.

Note: You will need to determine whether the 16-F module is currently in UL Fire Mode or Legacy Mode. In UL Fire Mode, the 16-F processor LED light will blink rapidly (8 times every second). In Legacy Mode, it will blink slowly (once per second). Check out this FAQ for information on switching between modes.

You will want to have all the resistors for your Qolsys IQ Hardwire 16-F module properly wired in before attempting to enroll the module with a panel. Additionally, you will also want to have any 2-wire smoke detectors used with module properly wired before attempting enrollment. This is so that the 16-F module properly recognizes Zone 16 as a Normally Open zone for 2-wire smoke detectors. Remember that any 2-wire smoke detectors used with the 16-F must be connected at Zone 16 with a proper end of line resistor. Up to ten (10) 2-wire smoke detectors can be used at this zone. Please see this FAQ for more information on setting up 2-wire smoke detectors for use with the Qolsys IQ Hardwire 16-F module.

It is recommended that you clear the memory for the Qolsys IQ Hardwire 16-F prior to programming. Do this after all wiring has been completed. In addition, if you intend to change the mode being used with the unit, it is also recommended that you clear the unit's memory. For more information on clearing the memory (factory defaulting) the Qolsys IQ Hardwire 16-F, follow the steps in this FAQ.