thermostat anticipator

Dick_2

The Honeywell T87 anticipator is set at 1.2 for our steam system. With the thermostat set at 66,
the room temperature is raised to 68/69 before the thermostat shuts the boiler down. Is it normal for temperature overshoot at this 1.2 setting?

Ted_4

The anticipator setting adjusts the anticipator resistance to match the current of the primary control or relay. 1.2 means 1.2 amps. If your primary is just 0.4 amps, for instance, the anticipator will not provide enough heat to the thermostat bi-metal coil, and room temperature will overshoot the setting. Look on the control or relay for the operating current. Set the anticipator to that current to start, then adjust the anticipator up or down until you get a burner cycle that is not too short nor too long. You will notice an arrow and "longer" on the anticipator scale.

Joe_30

If the device controlled by the thermostat is a zone valve/end switch , do you set the thermostat's anticipator to the amperage of the zone valve?

Joe_30

Using Honeywell T87 thermostats controlling Honeywell zone valves, do you set the anticipator to the rating of the zone valve or to that of the Honeywell aquastat? A thread a few days ago spoke of setting it to the rating of the "device controlled by the thermostat", which seems to me to be the zone valve and its end switch . Am restating the previous question to update and hopefully narow it . Joe

Unknown

you are right, Joe

Set it to the amp draw of what it is connected to. The zone valve in your case.

Noel

Dave_23

Anticipator setting

I have a new WM EG-35 steam boiler. Will someone please tell me where exactly to make the amperage measurement for anticipator setting. I'm using a T87 Honeywell, with the anticipator max'd out at 1.2. Note: The EG-35 controls are all electronic, with probe-type LWC. I don't believe there are any relays to be found on an EG-35.

Dale

I think

Seems to me that you are already getting the most out of the old T87f, If it over shoots the 3 degrees consistantly what happens when you lower the set point 3 degrees, might as well try it. Also where is the stat located, can you temporarily reduce heat in that space? You might want to buy the honeywell stat where you can select a fixed one cycle per hour for steam.

kk_2

Dave,

To measure the current, you will need an AC ammeter. You can place your ammeter across the R and W terminals and get a reading while the thermostat is NOT calling for heat. If the thermostat is calling for heat, it will be shorting out those terminals and you'll get no reading. The numbers on the anticipator are in amps.

If you can't get to the terminals without taking the thermostat off the backplate, then just put the meter on the R and W terminals on the backplate (still on the wall) - you won't have to worry about the thermostat calling for heat in that case!

-kk

Dave_23

Thanks

Thanks for the info. I'm reluctant, but willing to consider, a new Tstat with programmable setback, cycle/hour control, etc. My heating bill has increased about 25 percent, whereas my usage has decreased. I'm looking for additional ways to economize without major repair. I've already replaced windows, increased insulation, etc. It has helped, but not enough to keep Michcon/DTE at bay. Question to Bill at Honeywell: What is the manufacturer's suggested list price for the stats you recommended earlier on this thread?

Tom M.

One simple thing to check.

> The Honeywell T87 anticipator is set at 1.2 for

> our steam system. With the thermostat set at 66,

> the room temperature is raised to 68/69 before

> the thermostat shuts the boiler down. Is it

> normal for temperature overshoot at this 1.2

> setting?

Fred Harwood

Anticipation

I've had good luck with the T87. A bit of observation and small moves of the anticipator slider can eliminate overshoot, provided that the thermostat is in the right place to "see" what the heating system is doing.
First, what is the present cycle time (time from on to on again)?

BillW@honeywell

Dan's policy...

on this site is not to discuss prices. Anyway, Honeywell sells our professional trade products to distributors who in turn sell to contractors, who install them in your home. The retail line is sold thru the "box" stores like Lowes and Home Depot. For an electronic programmable, try the T8002C1000, electronic non programmable try the T8400B1018, or the new T8775A1009. All are +- 1 degree accurate, mercury free and compatible with your system. Just set for 1 cycle per hour, since allcome factory preset to 6 cph.

Dick_2

boiler cycle time

set at 1.2 was approximately 1 hour, but there was short cycling at this setting. I moved the anticipator arrow back to 1 and I can't believe the difference. Boiler cycle time is every half hour and it runs approximately 10 minutes. Gas usage is down noticeably and there is no temperature overshoot or short cycling. The Webster two pipe vapor system is heating fine after this change; vaporstat is set at 12 ounces cutout and main vent on dry return in boiler room has Gorton 2's.
Thank you all for your input to my many questions in the past. I have been unable to find a professional in our area that 1. has the interest in steam heating that you all have and 2. is determined to see that the system is operating as intended.

scrook_2

anticipator setting

shpild be the current draw of the gas valve (or the gas valve + the vent damper operator if there is one). If you can not find that info printed on them, then given you lack an AC ammeter and it overshoots, you could reduce it to 1.0 and wait a couple days, if more is needed go to 0.8, etc. A little bit may make a marked improvement. Too far and it will cycle off and on as it rises to setpoint even if the steam pressure is not high enough to open the pressure-trol switch.

Fred Harwood

Timing

I have restored Webster two-pipe vapor system. They run fine. On your new cycle time, how long before steam closes the mains steam traps (the mains are trapped to the dry returns, which lead back to the boilroom vent)?

Dick_2

on a 30 degree day with the T87 set at 68 degrees, the total

boiler run time is 4 1/2 minutes, with steam reaching the end of each main(there are 3) in 1 1/2 minutes. The boiler is rated 815 sq. ft. steam and the home is 3600 sq. ft. brick built in 1940.

Dick_2

as an addition to my last post, there is air being released

from the Gorton 2's in the boiler room within 30 seconds

Fred Harwood

Webster 2-pipe

Sounds pretty good. And if memory serves, that vapor system was designed for 8 oz or less of steam pressure.

Fred P

the user manual on my new burham boiler

states the anticipater should be set at 8.0, if you still have your user manual/installation book it might be in there

Dave_23

Balancing the heating system/Anticipator

I have a steam, two pipe Trane system controlled with a T87. Everything works pretty well. However, if I don't allow a little overshoot, the second floor doesn't warm up as much as I'd like. Question: Can I close the radiator shutoff valve (fully or partially) in the room with the thermostat, back off on the anticipator, and effectively achieve more even heat throughout the house, with the theory being that the rest of the house will have to heat up more to compensate for the reduced contribution by the radiator nearest the tstat.

Joe_30

Anticipators can burn out: How can you test to know if one is bad? Thanks, Joe.

Len

thermastat

i recently put in a new burnum gas steam boiler.I also added a new extenion on to house. I ran a hot water zone off the steam boiler using the bypass line to mix return water with the supply. iI bought a honeywell ct3500 programmable thermostat with smart time for new room. My old thermastat for the rest of the house which is the steam zone runs off a white-rogers programmable thermastat, am i using the right ones for both zones,and should i leave the steam side thermastat set at one temp and don'thave it go down to lower temp during the day. thanks

JM_2

Honeywell TS86

Does the TS86 for powerpile have a heat anticipator?
No set at Fact.

John Mahoney

Unknown

TS-86 has a fixed

anticipator of .1 of an amp to match the 750 millivolt system it is attached to. The millivolt drop across the thermostat should be between 115 to 130 millivolts. The thermostat should have no more than 30 feet of 18 guage wire in order to work properly. Watch out for splices in wires which can rob MV's from the systems.

scrook_2

you mean

0.8? typical anticipator range is 0.2 to 1.2 amps

scrook_2

pricing

YOu could go to www.grainger.com or another industrial/HVAC supplier and look up their catalog prices on the thermostats in question, or check w/ your heating service contractor about buying one.

Wayne_6

wide temperature swing

I have a new home with 3 zones. I have the standard, non digital Honeywell thermostats. My upstairs and first floor zones are operating properly, but my 3rd zone for a 24x24 family room kicks on late and sometimes stays on. For example, we have it set at 66 degrees and it won't come on until 60, but may now shut off until it's 80 degrees or we turn it off. The builder's HVAC man claims there is nothing wrong and it's because we have large baseboards (40 feet total) in the family room. As well, this thermostat is set just like the others. Any ideas?