Lennox AC system keeps short cycling. Short cycling accrues…

Okay

So, one of the hardest issues to diagnose, an intermittent issue.

there are numerous things that could kill voltage to the thermostat,(float switch, indoor board) but if it’s going into a rebooting cycle, I have seen this caused by a faulty IComfort stat. What we need to do is catch it and see if 24v ac is lost at the thermostat when it reboots.

If it never loses voltage, it’s almost certainly a problem with the thermostat.

Which version of the s30 are you using

Ok. Did this problem present after adding the hub?

Ok, so before you had the smart hub. Did you have a non communicating version of the s30 stat?

I assume now you have a smart hub and the thermostat is using Lennox communication wiring (r, c, i-, i+)

Ok so both thermostats used the same wiring but now you have a smart hub.

if the unit worked before without short cycling, this suggests an issue with the hub, tstat or furnace board.

The float switch may have been replaced, but was the drain line cleared ? Could also be getting intermittently blocked with debris and killing power

Depends on what type they installed. It’s usually right on the drain line or attached to the secondary drain outlet on the unit/cooo

Coil

This is one of those problems that is going to take a well seasoned tech on site. But I would start with basics first: verify drain isn’t blocked, you can just shop vac it out.  And verify if 24v is at the thermostat when it reboots. Just based off what I’m being told so far it sounds like the hub is the culprit.

If it’s rebooting it may not be “disconnected” and the thermostat may still have power.

The hub sends out 12vdc to the thermostat, 24V is not being sent out to the outdoor unit  directly from the thermostat. The thermostat just communicates back and forth with hub/furnace/condenser to tell it when it should energize the contractor

You have the magnetic mount for the thermostat right?

Ok. Well we can’t bypass the hub without using a different thermostat

If your drain goes into a condensate pump you may also want to verify it’s working properly with no blockages, sometimes condensate pumps also have float protection

Built in.

Does your furnace control board have the R c I I wiring inputs for both indoor and outdoor unit? If so then you can bypass it, but if not you can’t

Basically if your hub has the wiring r I I c twice (one for indoor one for outdoor available at the hub it can be swapped over from the hi.

Hub*

I wouldn’t try and bypass it though. Is this equipment under warranty