Honeywell Programmable Thermostat

Drod

I just replaced my old, round Honeywell with one of the new 7 day programable Honeywells (I think it's a CT3600). It's designed to be used for my single pipe steam system with the cycle adjustment they describe (which I did program in). In the morning during the wake cycle, the house heats to two degrees above my set temperature, i.e. it's programmed to heat from my night setting of 67 to my wake setting of 71, but instead of 71 it hits 73 degrees.
Here's my question: Should I adjust the program setting down a degree or two; or will this brainy (Intelligence Feature is turned on) thermostat eventually figure everything out and stop the boiler earlier?

tombig

Setback stat

Screw the recovery mode and set it to turn on 1/2 hour before you get up. I knew a Dale Rodeghero in Mokena, Il.

Floyd

It should have...

about 4 time periods a day... set it to come up to say 69 and then 71 and hour or so later

Boilerpro

Why its doing it....

Most old steam systems are way too big(both too much radiation and too big of a boiler), so when you set them back and up again they overheat because even if the boiler shuts down, the radiators are still very hot continuing to heat the space and causing overheating. I would make sure that the pressure is set properly.... under 2 PSI or less cut out.... because higher pressure means hotter steam and radiators. While I believe that my opinion is in the minority, the way to solve this problem is to reduce the output of the boiler so it more closlely matches the heat loss of your home. Then the system will need to be balanced with adjustable air vents on the rads (after the mains are properly vented, if not already). Making these changes will prevent the rads from heating completely, helping prevent overheating after setbacks.



Boilerpro

BillW@honeywell

Temp overrun

The stat "remembers" the temperature for the last 3 days, and starts the system in time to have the home at the setpoint when the "wake " period starts, not just turn the system on like the old mechanical clocks used to. Did you set it for 1CPH when you installed it? I also agree with Boilerpro...old steam systems may well overheat a bit, beacuse those hot radiaotrs will continue to put out heat long after the boiler shuts down.

tombig

Ratio Rest for Steam?

Many larger steam boilers have been controlled by time clocks and return line aquastat. I am a big fan of Ratio reset for hydronic.....i.e. controlling indoor circulating temps. based on outdoor air temp. Who makes a cap. tube (why electric?) control that adjusts return condensate temps. to outside air temp? I've looked at what's out there and it really doesn't seem suited for steam. seems like it would work for Dale....don't know if he already has a returnstat? Steam control in milder temps. is best addresssed by the return stat.


Tombig