programmable thermostats

Brad White_9

are simply switches that respond to temperature. In a steam system, the call for heat enables the boiler. The boiler then goes about mantaining pressure. It is all it knows to do.

The differential issues I believe you are refering to have to do with pressure control (cut-in to cut-out). I can stand to be corrected, but to my knowledge the setting back of the space temperature just tells the boiler when it is or is not needed to function. I cannot see setting back the house within reason as detrimental. The key would be is the system sized correctly in terms of steam output and connected radiation to bring the house back to temperature in a reasonable amount of time? Generally speaking, houses with steam heat tend to be older. Likewise they tend to be improved upon without changing their heating system (you still have steam or you would not be asking). Similarly you probably have the original radiators. Therefore the house should recover well, one would think.

The other part about programmable thermostats is, at least here in Massachusetts, you have to use them. Our energy code, while unique to MA, has a basis in several model energy codes. Manual adjustment types, at least in theory, are not allowed anymore according to my notes at the seminar. (I say "in theory" because who is going to police you?) To me they are a nice convenience and the kind with "Smart Response" technology self educates to meet temperature at a given time, not just your guess as to when to start.

I see no reason not to use one in your case but am all (eyes and) ears to learn different opinions.

Brian Lockett

Programmable thermostats

What are the pros/cons for programmable thermostats for steam heat systems? I understand the day/night differential should not be huge. 10 degrees would be too much, some say. 5 degrees is about right. True?

Some installers seem dead set against installing programmable thermostats, presumably concerned that overzealous home owners trying to keep heating bills down will set the differential too wide, triggering warranty problems.

But what's the difference if a homeowner, who wakes up to a cold house and raises the thermo setting 5 degrees manually or sets a programmable thermo to do this automatically?

Also - any recommendations for thermostats on a two-pipe steam heat system? Programmable Honeywell 6300B OK?