Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.


Gary_7 Member Posts: 25
I have oil fired boiler with a tanklees coil using a L4081B aquastat. It currently has one circulator heat zone wired through the L4081B. I'm adding two more zones including a super Stor indirect fired domestic water heater with an L4006A and another heating zone for a total of 3 to be wired through a newly purchased ARGO ARM-3P(I thought would simply things). Wiring of the thermostats, circulators and the L4006A looks straight forward. I don't however know how to wire the ARM-3P to the L4081B(boiler control). The wiring diagram supplied with the ARM-3P is slightly confusing. It mentions an L6081A and a L8124A. Does anyone have any experience with the ARGO ARM-3P? Can the ARM-3P be used with the L4081B?
Any replies/suggestions are greatly appreciated.

Thank You


  • Yes , we have used them

    and you can use the ARM-3P with a 4081B . But first , is the existing thermostat wire line or low voltage ? And does it go right to the thermostat ?

    In many homes around here we see a red wire that is powered line voltage right from the thermostat to the boiler , and in that case some rewiring has to be done .
  • Gary_7
    Gary_7 Member Posts: 25
    Line Voltage Thermostat

    Thanks Ron, here is some more info. The thermostat is line voltage. It is powered at the boiler switch/junction box. The white wire coming from the thermostat connects to a red wire which connects to the W terminal on the L4081B on the boiler. The black wire coming from the thermostat goes to the circulator.
    If it makes life easier I'm not opposed to changing to a low voltage thermostat. My main concern is the connections from the ARM-3P to the L4081B and burner control.

  • Ok , that makes it easy

    First , make sure all the power is off . You want to take out the thermostat wire from the 4081 and connect it right to the T-T of a zone on the relay ( not the priority zone though ) . You will need to run a power wire from the W terminal of the 4081 to the L terminal of the Argo . You also need to run a neutral wire to the N terminal of the Argo , as well as a ground to be safe . The boiler will maintain the high setting , but all the zones will shut down if the temp goes below the low setting . A better way to control the Argo and boiler is to use a Honeywell 8124A aquastat - it can keep the boiler at a minimum temp until theres a call from the Argo , then it ramps up the boiler temp to the high setting . Good luck Gary .

This discussion has been closed.