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Direct vent furnace thermostat replacement

Published / by bde / Leave a Comment

Recently I’ve had some challenges with stability on the low voltage thermostat that controls my 30000 BTU Williams direct vent furnace which I rely on to keep the cabin above freezing when I’m not here. Here’s the faulty one:

On several occasions I’ve woken up to temperatures of 50° where the thermostat failed to kick back on, so therefore I’m looking into replacement options. Grabbed 3 potential models to use from Home Depot, each with their own pros and cons and will decide which one is best for this application.

The first two units that require no external power source one being the “dumbest” which is a manually controlled unit, the second one being a little less dumb with a basic set of programs on a 7 days schedule that runs off a 2 AAA batteries. the semi smart one is a wireless thermostat that requires what’s called a “c wire”, and for my application requires a special power adapter that plugs into a 110 outlet in the adapter puts out 24 volt AC current. This is what the “semi-smart” thermostat needs to properly power it’s wireless other smart functions. Here’s the C wire adapter I ordered from Amazon:

This introduces more complexity in the heating system and adds an additional potential single point of failure, but I gain the additional benefit of being able to remote control and monitor the unit from afar.

Right now I’ll be testing out “semi-dumb” thermostat. It runs off 2 AAA batteries. That’s the advantage. Simple easy, virtually fail-safe.

Trade-offs…

Remote control vs potential for power failure.

Will see what model wins out in the end…