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T87K Thermostat slow to recycle

philg
philg Member Posts: 4
I have a gas steam heat unit and a Honeywell T87K thermostat. After the setting is

satisfied the radiators get cold before the next run cycle. The manual says to set the cycle

switches as; SW1 on SW2 on and the manual indicates ! CPH which I assume is one

cycle per hour.



There is an option to set the switches as; SW1off SW2on 3CPH. These settings are listed for high efficiency warm air. Can I set my switches this way?

Comments

  • Dave in QCA
    Dave in QCA Member Posts: 1,788
    cast iron radiators cold in 1 hour?

    You say your radiators are cold in one hour.  Do you have cast iron radiators or do you have convectors?  It is ok for a convector system to be set for 2 or 3 cycles per hour.  Cast iron radiators should be fine at 1 cycles per hour. 
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Dave in QCA
    Dave in QCA Member Posts: 1,788
    Adjust it for optimum results

    1 cycle per hour is what is advised for cast iron steam systems.  It is considered the most efficient frequency and in most cases it will produce very even room temperatures.  I have noticed that some of my tube type cast iron radiators cool faster than the column type. Perhaps the tube type has less mass.



    If you feel that your room temperarues are uneven as a result of 1 cycle per hour, you can always adjust it and see if it improves the situation. 
    Dave in Quad Cities, America
    Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
    System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
    Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.
    http://grandviewdavenport.com
  • Mark N
    Mark N Member Posts: 1,119
    Thermostat

    Phig



    I tried that thermostat and didn't like it . I changed to the FocusPro 5000 much better. Also it is still quite mild where I live and the boiler is off for hours in between cycles. I have thin tube cast iron rads and they will cool down to room temp in an hour or so.
This discussion has been closed.