Solution to monitor radon fan running?

Hello all,

I am looking for a solution to monitor that the radon remediation fan is running 24/7, and alert me if it is not. It is switched on/off with a standard wall switch in the basement. Not sure if a ST switch is the answer? If the radon fan motor itself is not running - but it doesn’t blow the circuit breaker - would the switch still show it ‘on’?

Am I making this too complicated? Has anyone looked into this? If so, what was your solution?


This is a great idea! I never thought to add this one, but I agree, I would love for a way to monitor it since I do not necessarily go into the basement every day to look and make sure it is running.


@baze68 - In your scenario - if the circuit breaker was still OK, then your switch would still have power and report itself as on.

One thing that comes to mind is if the only thing on this switch is the fan, you could get a Z-wave switch/power strip that also reports the power consumption (or one of the Aeon Labs micro switches which also report power consumption), then you would have to write a little app the monitors the power consumption and alerts you when it deviates from the nominal load with the fan on.

That’s not a bad idea. I wonder if I could also just use one of the “SmartThings Outlets” and put it in the attic with the fan. Pretty sure it is just plugged into an outlet up there that is on its own circuit. We just need SmartThings to get the power monitoring working on the Smart Outlets.

Yep, my radon fan has its own switch in the basement so it sounds like the Aeon Labs micro switch may be a good option. @Steve28 - Thanks for the tip. One question, is the ‘little app’ to monitor the power consumption considered trivial? I’m a ST newbie when it comes to coding little apps, but maybe this is the time to jump in and learn. Unless someone else wants to have it…??

I believe the best radon check would be something that measures the indoor/outdoor pressure differential. A fan can function but a blockage or leakage can defeat it. That is why new methods use a u-tube:

Since the differential is small, I suspect it would be difficult finding an affordable digital manometer with a ST interface.

Having said that, the archaic radon mitigation I did twenty five years ago still passes the test. It would be nice to get a more immediate warning, however, if it breaks down. I suspect if I sold my house, I would have to upgrade it with a u-tube as a condition of sale.

I’m researching a similar concept to deploy in my home. Mine focuses more on the energy savings of not running a radon fan when radon levels are low/safe. Current active radon mitigation design is to run a fan ie: attic fan continuously (24x7x365), which equates to roughly $100 annually for my home. I suspect I can reduce this drastically by not running the fan when deemed unnecessary. I found a similar project documented here:

I was scouring the internet, without success, trying to find some genius who has tied the meter readings into their home automation setup to control power to the Radon fan triggered by such events like:

  • high/abnormal levels,
  • schedule (radon can be higher in winter)
  • humidity levels (radon can be elevated after heavy rain)
  • water sensors (if the sump basket has water directed to it it usually means hydrostatic pressure is elevated along the footing of the home and elevates radon entering home as well)

This would all be possible with the addition of a radon detection device connectivity to the ST hub. Any ideas?


Hi @HandyAndy and @baze68 do you find any solution for Radon monitoring?

No, unfortunately not. If you find something please let me know.

I built one using a Vernier sensor and an Arduino.

Posting in case anybody stumbles upon this…took a foot or so of tubing (same as what the manometer typical has or use the one that is already there) take the tube out of the vent pipe, put the other end in a cup of water, insert tube back in vent, should draw water into tube, remove from cup, should now have a tube with water being held in tube by fan suction…place water sensor under tube…smartthings one with contacts on the top works well…when fan goes off, no pressure to hold the water up in the tube, water drops onto water sensor…for extra fun run tube to floor or attach right to top of water sensor to ensure it triggers…