I've been considering swapping the orifice for my far right heat exchanger of my 75k Carrier 58GS to a plug to 2/3 size it. It would still meet my heat load. Almost considering dropping to 1/3 since the only flame sensor in the furnace is in the intermittent(spark ignition) pilot assembly and testing how a 19k heat output really affects things, at least until I hit the -5f balance point but I think it would still be comfortable until I hit -10f or maybe design load but I might not be too happy at -20f without more insulation. ..not sure I want to burn 288 watts in the blower for three times the normal duration though so it would just be a test. I don't think it would be safe to take out anything other than the far right burner though because the high limit is sandwiched between the two left burners.

Is the thermostat as small as it looks or is that deceiving? Is the label about the size of a credit card, how big is it?
I'm also curious about what the web interface looks like.
Could we get a screenshot perhaps?
Also does it do any energy logging? My current thermostat counts runtime.

If you close off one of the burners, wouldn't the exhaust fan pull in more air through the remaining tubes and cause the mixture to go excessively lean?

I don't think that model has an exhaust fan. If I remeber correctly it's an old school pilot light model.

The high limit is in place to prevent the furnace from overheating. Lowering the BTU won't cause an issue with the limit tripping. Lowering input lowers efficiency to some extent because the heat exchanger becomes oversized realtive to BTU input.

I'd look for another furnace. Shop around and you might find a bargian.

The thermostat is a little larger than my LUX thermostat. If I had to guess, its roughly 6" x 4", but I will get measurements and get back to you. The label is bigger than a credit card.

I will be posting pictures of the interface a bit later today.

An oversized heat exchanger would be more efficient in steady state operation, but blanking off one of the burners will not give you an oversized heat exchanger since you'll only be using part of it. What would is downsizing the burner nozzles (or otherwise reducing the fuel flow) and then somehow adjusting the airflow to maintain the correct mixture. (I think you would then have to slow down the air handler to avoid condensation and corrosion, but I'm not sure.)

Alright, here is the low down on the interface. Its pretty simple (which I like), and is therefore easy to use. I'll take you through the whole thing.



http://ecorenovator.org/forum/attach...1&d=1385572195

First up, you go to motison's site and click the "My CyberStat" link up top.



http://ecorenovator.org/forum/attach...1&d=1385572195

You get your basic login screen.



http://ecorenovator.org/forum/attach...1&d=1385572195

Once you login you're brought straight to the controls for your cyberstat. From here you can do lots of fun stuff like override the temperature temporarily, or permanently (aka hold feature), edit your programs, and change the heating mode. You can see there is a drop down at the top of the screen if you have multiple cyberstats, you can control them all, just switch to another one and change things.



http://ecorenovator.org/forum/attach...1&d=1385572195

Here are the selections available from the mode menu. Its fairly self explanatory.



http://ecorenovator.org/forum/attach...1&d=1385572195

And talking about programs, you can choose from a few different programs. They're labeled as shown, but you can use them for whatever you want really. The "manual" program makes the thermostat work like a non-programmable thermostat, set it and it stays until you change it. Also, the manual program must be used if you want to override your temperature permanently (aka hold feature), otherwise at the next programmed set point change it continues to follow the program that is active.



http://ecorenovator.org/forum/attach...1&d=1385572195

From the edit programs drop down, you can edit the 3 different programs. This is a wonderful and simple interface. You have the same display for each day. You simply click and drag the bars up/down for temperature, and right to left to adjust the time. It takes about 10-15 seconds to program a day. Also, if you click and drag the day buttons, you can copy one day to the next. You can finish programming a week in about a minute.



http://ecorenovator.org/forum/attach...1&d=1385572195

Going back to the main screen, this is what you get if you click the my account button. It should list all the cyberstats that are registered to your account.



http://ecorenovator.org/forum/attach...1&d=1385572195

If you click on the edit button, this is the screen that comes up. From here you can calibrate the temperature sensor, and setup email alerts for certain conditions.


That is really about it for the web interface. As I said its really simple and easy to use. The changes made take maybe 30 seconds or less to take effect from my short experience so far.

There is a little more to the device that I'll cover, and that is done at the initial setup. From there you can change your heating system type (1 or 2 stage heating, setpoint differential, etc). It would be nice if this was accessible from the internet interface, but its really stuff you won't be changing so I can see why its done there. I will get pictures of that later.

Also, I do not believe this thermostat logs run time. There is no filter replacement reminder on it. I think that is a bit odd considering it would only be a few lines of code to add.

Here are a few pictures to get the a perspective on the size. Looks like I was pretty close with my guess.

http://ecorenovator.org/forum/attach...1&d=1385594677

http://ecorenovator.org/forum/attach...1&d=1385594677

http://ecorenovator.org/forum/attach...1&d=1385594677