Great video. Most technicians do not understand how these older style thermostats work. Yet, you find many still in service. Thanks for sharing your time and expertise. It is most appreciated.

You're possibly the only guy I've found so far to have any content on this particular thermostat. Not sure if it will solve the issue I'm having, but knowledge is valuable, regardless of it's relevant use at the time. Thank you.

This helped a lot! THANK YOU.

Thank you. Will try that a little at a time. The furnace is '98 Lennox Ghr26 variety.

Great video!

GFM, first off, thanks for all your videos. Here's my question. I recently purchased a Honeywell RTH7600 to replace a T87F for my pellet stove. My T87F had the anticipator setting at the mark between .8 and 1.2, which I presume to be 1 cycle per hour. Should I stick with 1 CPH for the digital? It came set at 6 and I reduced it to 3 but it still causes problems because as my stove is shutting down, the thermostat makes it start back up without going through the entire startup sequence that is required, thus basically dumping all of my pellets into the burn pot without the heating element being on to initiate the fire. The cycle for my stove is basically getting the requirement to run from the thermostat, then the pellet auger runs for a preset period of time, while the heating element is heating and then causing a fire, once the sensors in the stove determine that the temperature in the stove is going up, it then calls for more pellets, turning the auger on, and then it continuously runs until the temperature is satisfied at the thermostat. At that point, the auger stops, and the fire burns out, but the fans stay on as long as the heat exchanger is warm, to continue to blow warm air into the room. My current issue is that while the fans are still running, just after the fire has gone out, the thermostat calls for more heat, initiating the auger, but because the stove hasn't completely shut down from the previous cycle, it doesn't do a proper startup and just dumps pellets. Sorry for the novel, but I would appreciate your expertise on this one.

First time this explained to me With pellet stove Amp read across the 2 wires connected to thermostat Just ordered nos Honeywell Stat for above stove

I have a furnace that turns on and off every couple minutes, will adjusting this make it so it only turns on at 5 degree individuals? Or would I need a new thermostat for this? Seems like this isn't good for the furnace

Thank you so much this has helped me so much

Are there any thermostats where you can adjust the temperature range so that it won't cycle as much? Just a different way of getting the same result you explain here. Makes me curious though...

always good, thank you ...

Thanks for this helpfull video

Mechanical thermostat anticipator is factory calibrated to provide about 3 to 6 cycles per hour if set to the control circuit current draw. This is not appropriate for a steam boiler heating system because the boiler components and radiators need a longer cycle time to reach the boiling temperature of water, say 212°F. Set the anticipator slightly less than double the current draw and adjust the anticipator to provide a furnace run time of about 20-minutes for moderate outdoor temperatures around 40°F. During colder outdoor temperatures the furnace will likely run 25 to 30-minutes because of more rapid structure heat losses which impact the bimetallic thermostat sensor. If you cannot measure the current draw, it is usually the gas valve current draw plus 0.10 ma.

Appreciate the info. What do I do if the temp on the top and temp on the bottom don’t match? Example is my inside temp will read 65 but in order to get that temp, I have to set it to around 72?

my indoor temp reads 10 degrees higher on my gold honeywell, can it be calibrated? thanks

My concern is the pump will shutoff n I still have 140* temp on the gauge. So I want it to run longer before shutoff. Do I perform the same adjustment to the anticipatory or what can I do ?

Does a digital stat do this all by itself?

You may have covered this somewhere, but where would you test the amperage to get a starting figure? I think somewhere on my system, maybe the aquastat, there is a number, maybe .4 A, but where would I check it, anywhere in the thermostat circuit?

grayfurnaceman, Need your help ! I have a single pipe steam system. My old Honeywell Mercury thermostat went out and a few years ago I replaced it with a digital thermostat. I didn't like the way I set it for 72, it runs until 73, then is off until it drops to 71 degrees. I was getting to much of a "hot cold" in the house. I think I had it set for the 2 cycles per hour. I replaced it with w White Rogers simple "snap switch" type thinking it would be better and more accurate. My Amp draw on the gas valve is .23 amps. I set the Anticipator to the .23 and I'm still getting "swings". When it's in the 40's outside or high 30's, my radiators are getting cold, then heat kicks on and they get hot normally, but it seems to have to much "off time" and give me the same temp swings I had with the digital thermostat. I been messing with the Anticipator trying to lower and raise the setting from .23 amps, but am noticing no difference. I been reading to go higher closer to the 1.2 amps o the anticipator or steam systems, but all it seems to do is make it hotter, then colder, and it will be set for 72, but go up to 74 in the house before it shuts down. Any suggestions to solve this problem ? It seems the digital thermostat worked better at this point but I don't like it because of the 1 degree increment change option only. 72 is to cold, and setting it to 73 degrees was to hot in the house. Thank you

Why is the bottom set to 80? How do you change that ?

Okay I have question, so my heater keeps shutting off, I noticed when I tap my thermostat it comes back on then it goes back off it's starting to be a constant thing now, was wondering if you can explain, I have the same exact honeywell

can you do a video on wiring thermostat from the outdoor to in indoor unit and any thing you can think of about wiring thanks

my house is old ac sucks if i want it ac longer what should i do

GFM can you explain the amp draw of the heating system? My T87 is attached to the tt terminals of a honeywell controller on a hot water boiler. Can you also explain why you multiply by 1.2 to get the value for longer cycle times?

Hi "_' ...I need your help so desperately. I've searched & no luck. First off, I have really enjoyed your videos & bennifited from your knowledge. Thank you so much for sharing dear friend. I am def so very greatful. Ok so my q is: can we change the cycles per hour/anticipater with a Honeywell 7 day programmable thermostat & if so how? "_ '

Thanks!

Thank you thank you thank you!

If you read the honeywell instruction they 4 or 4.5 ,I do not really understand,how did you came up w/the current?

This is just the video I needed to see as I just discovered that I have an old Honeywell Mercury thermostat with an anticipator. I have never seen one of these until tonight as we have been trying to get our cottage to come up to at least 68 degrees. In order to get it to that temperature I had to set the thermostat to 76 degrees. We had an inspector in and all the temps on the wall units and boiler are perfect we just can't seem to get this place to stay an even temperature. He suggested a new thermostat which I bought when I took off the front of the old one to change it I noticed this anticipator for the first time. My Dad (who passed away) probably set this originally but I am lost as to where to set this anticipator since I don't have anything to get an amp reading. The numbers are hard to read. So can you tell me as a novice should I move it to the left for longer cycles and to the right for shorter cycles? Would the shorter cycles keep the place a more even temperature? Thanks for your help. Your video demonstrated to me how ignorant I am about all this. :-p

Which direction makes it cycle more and which direction makes it cycle less? I don't know the amperage. I'm changing it to 1.2 for the hell of it and seeing what happens.

I have Honeywell in my home. I’ve never encountered such a thing and I am very confused. The bottom part doesn’t move and remains on 80 degrees. I can adjust the top to water degrees I want. How can I fix this?

and how to wire safety switches in to the wiring

This may be a long shot but here goes. I have a TH5-20 in an incubator I made and was wondering is there a way to change the differential ? Its to big of a gap in temps so I need to tighten the gap quite a bit. Is there a way to do that on this type of thermostat?

Ok so I’m trying to increase the time between cycles. My anticipatory was at .7 n times 1.2 gave me .84. I have it at .8 n seems to have done what I wanted. Does the senerio sound rite ?

I got rid of my digital thermostat, got sick of changing the batteries and bought a T87. My old Bryant gas boiler system with hydronic cast iron radiators appears to put out .1 amps. Does that sound low? I guess I’ll find out this winter if it cycles too much, I’ll slide the adjuster over.

After listening to this video I checked my anticipator and found it all the way up to 1.2 Been wondering why my water based heat pump was running so much. I dropped it to .3 to see what would happen. PS how did you determine the amp draw?

Hi I have one I want to put it in my garage I have 3 wires red green and white but only two screws witch wire do I use thank you it's a gas furnace

I believe I have a boiler, it’s the old radiator heater system type that heats the house with steam. I got my gas bill too extremely high! To my knowledge I don’t abuse the heater. Is there a possibility my boiler is too old and uses lots of gas? Or would adjusting the thermostat like you mention on this video help me control the heater more? And if I replace my boiler with a new one, is there a possibility I could buy one that helps me save on gas?

Thumbs up for everything you cover. My owners manual said to make a ten coil jumper between the R and W and then divide the reading by 10 to get the actual amps. So I did. With the house at 70 and the thermostat set on 80 the mechanical thermostat would run for about 6 minutes then shut off; wait another 6 minutes run for 6 minutes and shut off. I can assure you it was not a short cycle from the unit. The original digital thermostat would run for as long as it took to get it to the setpoint and then shut off. Can a mechanical thermostat be forced to make the furnace run to the set point or are the start/stop intervals set in stone. What if I wanted the furnace to run for an hour with no interruption?

Hi, I'm glad to see your handle still showing up on KZfaq! I have a really simple question? How can I get at the anticipator on the basic white Honeywell round in the hallway of the apartment complex where I live? I cannot seem to figure out how to remove the cover ring, and I don't want to tug on something the wrong way and end up standing in the hallway holding a thermostat in my hand and wires dangling out the back of it and out of the wall...! It seems to be mounted as level as possible, ther are no switches on the exterior, just the plastic disk you turn to adjust the heat. The problem is that when it is set to 72-74F, it heats only to 68F. I'd like to adjust the anticipator so that a setting of 70 yields a temperature of 68. In other words, so the set point and temperature maintained are 2F apart instead of 5-6F apart. Please helllllp! I won't touch anything until you instruct me how to get inside it. Promise!

Why are you multiplying by 1.2? Where does that number/constant come from?

How can I change mine? It's set on 5, but it's been like that since before my father passed away. It's just too hot sometimes, can you please help me? Thanks!

Does this really only let the unit run 6 cycles per hour? I remember my 1st boss teaching me about this but mercury stats are pretty much gone.

I’m confused on the cycle, what’s the perfect cycle to have it on so the house is not cold or to hot? I live in an apartment and we control our own heat and I have the same Honeywell thermostat in this video. I have poor circulation on the windows the cold air always gets in so I need to make the house warmer

My thermostat is constantly on. How can I turn the heat down or off. Please help

How do I calibrate an OLD “FAST” thermostat that looks similar to this one. It’s probably from the 1970s. It’s low by about 6 degrees.

Mine is short cycling and I was gonna ask but the variable resistor just smoked and burned. I suppose if I knew the correct value I could solder in a resistor and have no adjustment or add a variable resistor? I keep them in stock in fact of many sorts. I'm getting .3 to .4 ohms across the entire range with the pointer lifted off the resistor. So I'm assuming I could start with about half of that? And see if it works until I can get the newer 87N version of this round thermostat. After seeing this thing smoke I think I know why they don't make em anymore. But give it ts dew it is very very old. Also It only takes one time for something to smoke and burn to see an old house burn to the ground! So I'm gonna add a fuse to my 24v power supply after seeing this and hope for the best. If it burns to the ground hopefully me and the wife will be out for a drive! Right?

Mine is all the way down at 1.2..would that cause my heat to never shut off?

How to clean this type of thermostat from cigarette smoke and household dust?...Please :) Thank you very much!...:) :) :)

We have an older Thermostat than this..Its Tall square shape so i Don't know how to adjust it.

Im really stupid because I'm still not sure what I'm suppose to do to lower the cycle rate. Of rather have absolutely NO cycles honestly, but there's not an off switch. My place is always so hot. (Second floor, brick building.) Numbers arent my friend.

As i write this i just cleaned my Old thermostat (Hunter 4035A - 350 ) as it was very dusty and will see how it acts now... But i get confused on setting this with my Gas furnace which as far as i can tell is OLD .(Rheem).. Issue im trying to address is to much gap between when it comes on and then back off. Like it gets feeling cold, and it needs to come on, but isnt and then when it does, it gets to warm before furnace and fan has stopped . Im a renter and the landlord has no clue and has not sent anyone to look at it... Also its a very old building but has insulation... Last winter the blower fan was replaced ,,, which i had to do all the phone calls and leg work , and a local guy here said yes the furnace is old and he had a hard time getting a blower that would work with it.. He said it is Old but a goody....It looks like Rheem model number may be 3204-80JB,, gas fired force air..

Just tell me if following all your advice will stop my kids from touching the thermostat

So less cycles = longer boiler burner running time ?

I still don't know what is "higher vs lower" (is it Longer or shorter?) I have a forced air gas HVAC unit (not a heat pump) the house could be insulated better. It is what it is. When the unit is off there is no heat. House gets cold quickly I use space heaters set low to buffer this out. Where should the anticipator be set? (Longer or shorter?)

Dude what?

man, you take forever to get to a point.. more explaining next time please

Huh?

the guy never actually explained any thing....