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Are my cycle times normal?

Based on everything I've been reading on this site for a while, I don't think my cycles are acting properly. Quick facts: residential 1 pipe steam with 6 rads, 25' main, insulated pipes, good main venting, well maintained boiler, manual Honeywell round thermostat, vaporstat set properly, proper rad venting.

Obviously outside-temperature dependent, my cycles are lengthy and spaced out for a 66 degree house,

40 out - 30 min cycle every 4 hrs

30 out - 30 min cycle every 3 hrs with vaporstat cutting in1-2 times.

20 out - 35 min cycle every 2 hrs with vaporstat cutting in 1-2 times.

10 and below - 35 min cycle every 1.5 hrs with cut in 3-4 times.

It seems like my cycles are too far apart - rads get cold instead of at least remaining lukewarm, Before I start asking how to fix this, am I losing my mind or shouldn't I be cycling more with shorter firings? thanks!


  • conversiontime
    conversiontime Member Posts: 87
    edited December 2013

    on the swing being called for in the boiler. Those times seem pretty similar to me (I keep in near 60 when gone/night and 65 during home.) but see below.

    The fact the vaporstat is kicking in repeatedly when boiler works harder should be studied. It sounds as if you need more main venting b/c the system may be building pressure b/c of vaccum / air traps in the lines. If firing more frequently then these air pockets are still trapped in line which causes vaporstat to shut down the boiler. Look at your main lines and see if how old/what type. You can put a piece of tissue on the vent to see if it is properly purging air.
  • Mark N
    Mark N Member Posts: 1,090
    Cycle times

    It makes sense that the boiler will run longer and more often the colder it gets outside. You say you have a Honeywell Thermostat. It is the old mercury type with an anticipator or is it the new type with the CPH switch? What is the vaporstat set at? A 30 to 35 minute run time to maintain temp seems very long. My boiler usually runs from 18 to 22 minutes to maintain the house at 70. It will run more often the colder it gets outside. I have a pressurtrol and never cycle on pressure.
  • responses

    I've got 2 functioning Gorton 1's for main venting. Vaporstat to cut in at 8oz with a diff of 6. And my Honeywell is the old school kind with anticipator set at 1.2 for steam.

    Appreciate the feedback so far!
  • Mark N
    Mark N Member Posts: 1,090

    I think at 1.2a anticipation is cut out try it set at 1.0a and see how it works. My Burnham manual recommends a setting of 0.8a.
  • Anticipator

    Good suggestion Mark. I've done this in the past(dropping it to 1) with mixed results, Cycles run for 20 mins, obviously a bit more frequently, without ever needing a cut-in but my farthest rad only gets 1/2 hot, That last rad already has a Gorton D on it so I can't force it to heat any quicker. I guess I was just hoping for a happy medium! Looks like I'll try to tweak a few rad vents to slow down the others and try to balance it out.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,510
    Slightly uneven heating

    If some radiators seem to lag in their heating up, measure the back-pressure of venting with a 0-3 psi gauge. All the air should escape easily at 2 ounces-is that the case.

    In that case, the supply pipes will be full of steam before the steam rises to the radiators-all equally. The amount of fuel burned in this country to compensate for bad main venting is equivalent to all the cars here driving with dragging brakes. It is a waste, and should be corrected ASAP! These gauges should be standard equipment on any boiler, along with some advice on interpreting the readings!!!--NBC