Honeywell tstat CPH

Rodney Summers

Its a Honeywell RTH230B. states as follows 2=30 mins Steam/gravity ...3=20mins hot water,90%+ high effiency furnace...4=15mins gas or oil...5=12 mins alternate setting for gas and oil..6=10mins electric

Rodney Summers

I was hoping someone here can help me understand my digital Honeywell TSTAT. I have a steam boiler and i set it for steam which is for 2 CPH. Does that mean that if by 1/2 hour it does not reach desired temp the TSAT will shut down temporally and restart shortly after? if so how long does it stay off for?

superMARKet

Cycle rate

The cycle rate only comes into play once you've gotten into a steady state, where the ambient temperature matches the setpoint (plus or minus a little bit of swing). If the ambient temperature is well below the setpoint, the thermostat lets the heating equipment run longer. The thermostat will respond more or less immediately with a call for heat if you adjust the setpoint manually, or for programmables, when it decides it's time to enter recovery from setback.

When the temperature is on the mark, the thermostat uses the cycle rate setting as a target, so it winds up varying temperature swing a little bit. It doesn't mean that you'll always get exactly the set number of cycles per hour.

I haven't seen a Honeywell digital with a 2cph setting. They've got a 1cph setting which is perfect for steam.

superMARKet

RTH230B

That's a newer consumer retail model. I haven't played with one yet, but if they're anything like any other digital thermostat Honeywell's ever made, the cycle rates are just targets, and there's no real fixed maximum number of minutes that it will call for heat if it's not satisfied. I bet the minute figures you're seeing are approximations that were only included because it's a consumer 'stat. Minutes are easier to grasp than cycle rates.