Technical > Home Improvement > Honeywell Round Thermostat

said by ArgMeMatey:

Contact Honeywell pre-sales support and ask them what the acceptable range is. I've done this using online chat so I had a record of what I was told.

You can also find your control transformer and see if it has multiple outputs. It would be unusual to have a 32 VAC transformer, but it's not out of the question that a nominal 24VAC xfmr would put out 32 VAC, especially if it's older and manufactured to looser tolerances. Or there's a slim chance it has more than one tap.

For my doorbell I have a 3-tap that does 8/16/24, but my HVAC transformer is fixed. I just measured it with an analog meter at 24.5 VAC, although it is currently loaded by the zone controller.

If in doubt, you can probably swap out the transformer cheaply as long as it's not part of the furnace or some other controller.

said by ArgMeMatey:

In that case, you might also check a site like heatinghelp.com.

There are probably a million Riello oil burners with identical transformers and all kinds of Honeywell stats, so chances are somebody there has already scratched this itch on their own head.

Best to you.

said by SparkChaser:

I think it's what alphapointe said; it's unloaded, your meter may be off. Peak voltage on 24VAC (RMS) is 34 volts.

FWIW, I did what you are doing. I replaced the round one with a new HW stat similar to what you are doing. In my case it operates a relay but the voltages are the same.