My heating system is very simple - a gas boiler, with no pumps or blowers. In an effort to be more "green", I purchased a programmable thermostat and installed it. It works fine, but is a little confusing. We recently rented the house out for a week, and the guests couldn't figure it out.

I would like to replace it with a simpler and easier-to-read one. Of course, I could just get an old fashioned round one, but I would like internet connectivity and the ability to program it. I could get a Nest or other similar one, but they are fairly expensive (>$200) and have more controls than necessary. As I said above, there are no fans or pumps, and also no AC. Any thoughts?

I really liked the simplicity of the original one. The old boiler had a pilot light and there was a thermocouple in the pilot which generated enough electricity to open the gas valve. Hence, this boiler ran without any external power; this was very useful during our sometimes long power outages (such as during Sandy). The thermostat needed no power (it was simply a mercury switch (I guess those are now illegal); shorting out the wires opened the gas valve. However, when the boiler was upgraded to a more efficient one, I lost that simplicity.