Honeywell thermostat heat anticipator

Jason_15

I just put in a new old-style honeywell round mercury thermostat. My question is on the heat anticipator- Honeywell says for scorched air to set it at .3, the smallest number, and steam to set at 1.2, the highest number setting. Hot water was around 1.0, close to the steam setting. It doesn't specify what type of water heat- since it is close to the steam setting I would assume Honeywell is thinking big cast iron radiators. I have copper fintube baseboard, so it is a big difference from large cast iron radiators. I would think my setting would be closer to the scorched air setting, since I wouldn't have such a "hot mass" giving off heat after the boiler shuts down. I would like to lengthen the cycle burn time as much as possible, even if it sacrifices a little bit of comfort. To lengthen the cycle time, would I go more towards the steam setting, or more towards the scorched air setting. My boiler is properly sized to the load and the heat loss, and it can run for a long time without hitting the high water temp aquastat, so longer cycles should give me better efficiency, and reduce system wear and tear. ( system was designed and installed by a pro. but previous HO put in a cheesy digital thermostat that wasn't compatible with my boiler)

John@Reliable_10

Where to set

Jason, If system has Taco zone valves set @1.2. If no zone valves set at 1.0. The proper way is to use a amp meter so both T87 and control are instep, but the above will work 99% of the time.

Ken_8

Jason,

You are on the right track. The longer the "on" cycle, the longer the off cycle. The science is interesting, the comfort everything.

Do EXACTLY what your doing now... Continue moving the anticipator/pointer towards "longer" cycles (which you've already properly identified as an energy savings event)until you notice the slightest on/off "discomfort," - then drop it back a hair and you're done!

The zone valve make, stack damper draw, gas valve resistance, wiring resistance, transformer output, etc. all have inter-active impacts. The old 10 revolution around the jaws of an Amprobe trick, is a good starting point, but no where near as good as your own body thermostat.

Let us know how it goes when the cold weather hits.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mike T., Swampeast MO

What an exceptional reply!

The anticipator really is a comfort device yet few bother to take the time to set as it relates to comfort.

Jason_15

Thanks and more info.

Thank you guys so much!! My system is even simpler than that- I have no zone valves because it is all 1 zone with monoflows (In the future I would like to separate the upstairs and downstairs into separate zones) and I have no stack damper because it is a Weil Mclain VHE 87% power vented boiler. (59000 btu output in a 120 year old home in Wisconsin that needs that many BTU's)

Big Ed

Your own Home

I would be afraid to leave a open option to a customer , unless your are going to be paid for the extra visits... You know what I am saying.