Both are only 12-hour, though, unfortunately.
Carleton
In a message dated 2003-01-26 13:13:15 Eastern Standard Time, [EMAIL PROTECTED] writes:
2003-01-2614. Why did my displayed temperature drop about 50 degrees (slipping into Celsius reading)? There is a temperature conversion screw marked "C" on the back of some thermostats. When it is in tight, the thermostat will display temperature in degrees Fahrenheit. When the screw is turned out (lose), the display reads Celsius. Simply backing the screw out, re-tightening, and pressing the RUN PROGRAM key should put your thermostat back into the Fahrenheit mode.
Bill,
Your posting reminded me of the situation with my Honeywell CT2800 model thermostat. I had won this thing as a door prize some years ago and never used it until recently. Like you I had an older thermostat of a different brand that was in degrees Celsius, selectable by a solder jumper. I just changed the jumper so it would work in degrees Celsius. And everything was fine for many years.
Then one day it broke and I was forced to use the Honeywell. I called the Honeywell 1-800 service number located on the bottom of the attached instruction label. I was told by the kid who answered that the unit could not be converted. After your posting, I decided to get the model number and check the web site and lo and behold, I found this:
http://content.honeywell.com/home/ptc-thermostats/CT2800faq.htm
http://content.honeywell.com/home/ptc-thermostats/CT2800.htm
24. How do I switch the thermostat from reading in Fahrenheit to Celsius, and vice versa?
On the back of the thermostat, there is a screw labelled C. To display the temperature in Fahrenheit, adjust the screw in. To display the temperature in Celsius, adjust the screw out one turn.
I have yet to find the screw mentioned, but as soon as I do, I will change it. I am surprised they don't mention this is the literature or in the manual.
This model will only operate in the 12 h mode:
http://content.honeywell.com/home/ptc-thermostats/therm_digchart.htm
I also wonder how they keep track of the units that are destined for the US market and those for non-US markets. The model number does not appear to change. I wonder if they just default all units to Fahrenheit and allow the installer to change the scale when installed. This is a sneaky way to get Fahrenheit into metric homes, as in some cases the installer might not know how to set it for degrees Celsius or lie to the customer and say it can't be done.
Who else out there has come across this situation? What is the experience of our friends in Canada and Mexico (NAFTA countries)? What about the EU and Australia? Are these products usable in your markets or are your systems so different these thermostats can't be used anyway? Inform us!!
Check out the operating specs on these models and see if they will work outside of North America. These units operate on 24~30 V-ac. If they don't, then I can see where degrees Celsius is a moot point for them and the ability of them to work in degrees Celsius is meant for the Canadian and Mexican markets. But, do they set the default to degrees Celsius when sold in these markets? That is an important question to have answered.
http://content.honeywell.com/home/ptc-thermostats/thermostat.htm
John
