Honeywell thermostat

[fan-of-fans]

I always liked the round Honeywell thermostats that you used to see, particularly when the house also had round a/c vents. I noticed they do still make these round thermostats, but of course they're plastic. There is a digital version too that works similarly by turning the dial and has a green backlight.

 

[wayupnorth]

I have 2 Honeywell round thermostats, one up, one down that were installed 22+ years ago. Being the wind chill with brutal temps is sub-zero right now, they kick on the boiler exactly where I leave them set and I am comfortable. I leave the temp set and dont want a digital up-down. Set it and forget it is what I do.

 

[johnrk]

My Home

was built in the mid 60's. When I bought it 20 years ago it still had the original round Honeywell thermostat, the one that they used to advertise in magazines. And yes, the vents in my ceilings are those round ones with a rod to pull with a knob on the end, to cut off the air flow. I love those round vents, too.

I miss seeing the huge ones that used to be in mid century department stores.

 

[petek]

Our house still has its original Honeywell roundie from 1958.. Since we have boiler heat there's no point in changing it to something more modern with setbacks and setting for non existant air conditioning , we have a mini split for that.

I put one of the new plastic roundies in moms house about 9 years ago and I had to get it in Michigan because all the ones in Ontario are in celcius. She didn't like celcius because there's not as many degree markers on the dials plus she was old and liked her Fahrenheit. lol

 

[johnrk]

petek-

What's a 'mini split'?

 

[gusherb]

I have a collection of T87's and even some T86's and other various old thermostats. I love the styling and simplicity of the T87, and I love the complexity of the electromechanical setback thermostats.

I have installed and used a few of them here but ultimately technology wins out in this case. Digital thermostats, particularly Honeywell are just unbeatable in temperature control. The T87's are almost as good as a digital Honeywells for heating but fall way short for cooling. Plus I really like being able to control everything from my phone, which I can't do with a T87.

As for the digital Round models those were never a reliable thermostat, they used triacs for switching which often failed, and I've seen many where the thermistors have gone haywire. I always thought a digital thermostat the shape of a T87 was cool though, they even had a programmable one 15+ years back. The electronic T87N that replaced the T87F is fairly reliable though.

 

[petek]

Mini split, ductless a/c since we don't have forced air heating/ac

http://https//www.homedepot.com/ser...8OkEJCZQ.0&utm_referrer=https://www.bing.com/

 

[fan-of-fans]

My grandmother's house had one of the metal round ones on her central a/c system.

I too miss the big round diffusers in stores. My local Winn Dixie and Bealls Outlet still have them despite the stores being remodeled. My old Publix used to have them also and some of the stores in that strip mall still have the smaller ones such as the barber shop, laundromat, and a space that I think is an office of some sort but has a post office walk up window.

And on Honeywells, my house used to have a rectangular Honeywell thermostat that was gold. It had a circle on the left of the face that showed the room temperature around its perimeter. It was replaced with a digital thermostat that says "Simple Comfort 2000" on it. It was an old Fedders HVAC system.

 

[gfm8959]

Setbacks

Do they really save fuel or is it better to "set and forget" at one constant setting??

 

[gusherb]

Setbacks

That is purely dependent on the home itself, the length of the setback, the efficiency & sizing of the equipment and whether you're setting back in cooling or heating mode.

The best case for a setback is an average insulated to leaky/uninsulated home with an oversized 80-90% efficient forced air furnace. The worst case would be a well insulated/sealed home with radiant floor heat or any kind of radiators.

If you have a furnace sized per Manual J and have a decently insulated home then an 8 hour setback of even a few degrees could wind up costing you more in fuel reheating the home than just leaving it set to what you desire all the time. You certainly don't wanna do more than a 3 degree setback with a properly sized forced air system, or hydronic system. In more than one case I've found it cheaper to leave the thermostat alone after replacing equipment with something more efficient and properly sizing it.

For A/C it's best to leave it alone in almost all cases.

 

[philr]

I collect Honeywell stuff, mostly thermostats!

I have a few that I'll probably never use but I like them anyway!

The round one in my kitchen is labeled as a Crane, I have a similar NOS cooling thermostat that I don't use since I don't have central a/c. There used to be an humidificator the humidistat was left there when the previous owners removed it. I have no idea how it worked since I have hot water heating, no ducting. I also have Honeywell Tap Lite switches.
The thermostat for the bedrooms is a rectangular Honeywell too. The one in the garage is newer round thermostat but still quite old. I also have an indoor/outdoor thermometer and quite a few old Honeywell thermometers.

I also have a few with a setback timer, including two round ones with a mechanical timer.

Here are a few pictures.

 

[DADoES]

 
Family's 1964 house had a Honeywell of this style.  Heat-only system.

Had separate Heat (left side) and Cool (right side) setpoint levers on top.  Cool was always at the max end of the range although it wouldn't do anything regardless of the setting.

 

[gusherb]

These are the two drawers dedicated to thermostats. I need to thin out some of the digital thermostats.

 

[moparwash]

Digital Round

Here is the Digital Round, that I replaced the non-digital one in 2007. It displays the room temperature, but when you turn the dial, it shows the set temperature and automatically lights up when you turn the knob. You can push the light button to light it up as well. 70-72 is good in the winter and 76-77 is good in the summer. When I got it, the instructions in English were missing, so it was either wing it on the installation (which was not hard), or learn Spanish!

 

[cuffs054]

My Aunt had an old Honeywell that I never understood how it functioned. It was tall and narrow with a metal case and no switches. It controlled a Frigidaire ground source, water cooled AC and propane furnace combo. To switch from c to h there was a large crank handle mounted near the top of the unit between the cooling and heating sides. When the handle was cranked it sounded very much like a large damper moved to block off either side. That was all there was for controls. The thermostat controlled both functions.

 

[iowabear]

Phil - enjoyed seeing those photos.

 

I grew up with the rectangular gold Honeywell, #5 in your photo set.  It was in use from the time my family bought the home in 1970 to when the furnace was replaced in mid-2000s.  I think the furnace was nearly 50 years old when it was replaced but I'm not 100% sure.

 

Do you know year were those made?

 

[fan-of-fans]

Those rectangular Honeywells in reply 12 first picture look a lot like the one that was in this house, except it had a circular temperature gauge instead of in a line.

On the digital round thermostat, does the light stay on if you press the light button, or does it go off after a period of time?

 

[moparwash]

The light goes out after about 5 seconds

 

[gusherb]

Cole

You would be describing the T872, the predecessor to the T874's you see in my other photos. The predecessor to the T872 is the T870 pictured in reply #11

The T870 was made in the 1960s, followed by the T872 in the 70s, and the T874 in the 80s til around 2006 give or take a year. The most noteworthy difference between the T872 and T874 was that the heat and cool lever were together in the T872 and separate in the T874. The T874 was Honeywells top of the line non programmable mechanical thermostat, mainly used in commercial settings where multistage equipment was used, requiring a thermostat that could control multiple stages of heating/cooling. It was just about the most accurate mechanical thermostat ever produced as well.

The particular T872 in my collection was made the 24th week of 1977.

 

[gusherb]

Two of my electromechanical programmable thermostats shown here, and a few of my oldest ones as well. The Carrier was the one that controlled my grandmas 1960 Carrier furnace, I imagine it came in the box with the furnace.

 

[cuffs054]

GusHerb, the unit in pic 6 far left looks like the one on my Aunts HVAC unit. Can you help me understand how it controlled both function with no other controls?

 

[gusherb]

The thermostat would've had three wires and been a heat/cool model. The mode selection would've been controlled elsewhere. These were uncommon but did exist, the most recent example is a Honeywell zone system from the 80s-90s called TrolATemp where a "master" thermostat controlled the system mode and the others were called "slave" thermostats. The slaves had three wires run to them and could do heat or cool.

The thermostat in the top right is another like the type you describe, except it is heat only, just like the one before that you pointed out.

The other Honeywells are T86's, the low temp one is an early T87. Two of the T86's were the original smaller dial design, one is for electric heat only, and the other has a positive off switch. Those are the only two smaller dial ones I have.

 

[diesirae7]

nice

collection you have! I've saved a few, there is a heating supply store here that still has new ones in stock, if you are looking for a certain one I can see if they have it. They also have lots of vintage NOS plumbing, like sinks and toilets still new in the box from the 1970s.

 

[gusherb]

Wow! Sounds like I need to make a trip!

 

[ken]

This thread came at an opportune time as I just got three used round, mechanical, heat only Honeywell thermostats that I installed and have a few questions I hope someone here might answer.

The one Im having most trouble with is a T87F2873. It has provision for three wire hookup. Base plate states Red to R, White to Y and Blue to W. The system is hot water radiator and uses only two wires. Only way thermostat works is hooking wires to R and Y but it operates backwards. If I turn the set temp lower than the room temp it turns circulator on. If I turn the set temp higher than the room temp it turns circulator off. I knew it wouldn’t make a difference but I reversed the wires and it operated the same.

The other two I installed are not the exact same model as above (I don’t have the model number of them while I write this) and seem to be working okay but there are a couple things Ive noticed with them. Number one will allow the room temp to drop at least three degrees below the set temp and not call for heat. Just how much its allowing the room temp to drop before turning the circulator on Im not sure. How many degrees is acceptable? Should it be calling for heat when the room temp drops exactly to the set temp?

Number two consistently shows a room temp 6-8 degrees above the set temp. I realize that after being satisfied and turning the circulator off the room temp will continue to rise some but this is not the case. Im finding the higher room temps with the baseboard cold to the touch. So it seems the thermostat is keeping the room temp higher than what its set for.

What is the adjustment made with the copper colored pointer at the 5 o’clock position? The scale below the pointer has numbers 1.2, .8, .6, .5, .4, .3, .2, .15, .12, .10. At the right end of the scale is the word LONGER with an arrow pointing towards the left. For some reason the pointer on the T87F2873 will not move the full range of the scale like it does on the other two.

Thanks for any info anyone here might be able to give me.

 

[ken]

Okay. Did some checking online and looks like thermostat should be hooked to R and W for heat only. Im sure I tried that but will try again and see what I get. As far as adjustment scale at 5 o'clock position I see that is to be set on the number that corresponds to the current rating of the primary control of the system. Something must be jammed or broken in thermostat that's not allowing the pointer to be moved full length of the scale.

 

[philr]

Ken, if your baseplate has no switch for heat/cool, you want the wires to be connected to the two lower left terminals of the baseplate, the upper right terminal is for cooling. If for some reason, the thermostat doesn't work with these terminals connected, there must be a problem with it.

As for the anticipator, from what range can you adjust it? This model should be adjustable from 0.1 to 1.2 according to this:

https://customer.honeywell.com/en-US/pages/product.aspx?cat=HonECC+Catalog&pid=T87F2873/U

As for your thermostats keeping the room too cool or too hot, first, verify that the red pointer shows the actual room temperature accurately (with at least another thermometer as a reference next to it). If it does, then the angle of the baseplate might have to be adjusted a bit so the mercury switch trips at the correct temperature (that might cause the thermostat not to be perfectly level but if it's more accurate like that, that's better!). And you have to make sure that the anticipator works and that it's set correctly so the system cycles on and off the appropriate time to maintain the room temperature. On my system, they should be set at 0.4 but I set them at slightly shorter settings around 0.35. The temperature is constant and follows the pointer setting on my old thermostats, at 0.4, the cycles are a bit too long and they'll still call for heat for a long time and the room temp would rise a bit above the set temperature.

On most of my old thermostats, I had to adjust the thermometers so the pointer shows the correct room temperature and I didn't install them perfectly level to compensate for wear(?) or incorrect adjustment of the bi-metal. I had a few with anticipators that either didn't set low enough or didn't seem to work at all but most worked just fine.

 

[ken]

Phil

Thanks for the info. The two left terminals are R and W. I will try them and see what I get. The pointer on the anticipator has very little travel. Only from .275 (the line right of .3) to half way between .2 and .15.

I know the anticipator isn't set correctly on the other two. I will do that and then see how they act.

 

[diesirae7]

Heat anticipator

That is actually a mini heater in the thermostat, once a call for heat it slowly warms to shut the thermostat off before the room reaches temperature, the furnace will continue to blow out heat after its off and reach the temperature the thermostat is set at. Those numbers on the slide are milliamps, it must be set to the milliamp draw of the gas valve, which would require a milliamp meter installed at the thermostat to see what the amp draw of your gas valve is, sometimes the gas valve will have it printed on the body, one thing you can look for if you don't have a milliamp meter. Even new digital thermostats have this option, in a series of numbers called differential or something like that. Also its very important to level the sub-base of the mercury thermostats for them to work properly.
This post made me check my old thermostat drawer in the shop, looks like I have about 4 Honeywell Rounds, I've always saved them after replacing thermostats for people. I have a really neat Lennox brushed aluminum rectangle thermostat from the 50s in a box somewhere, I'll have to try and find it.

 

[philr]

I assume the thermostats have to be set to the current draw of the gas valve (in amps) on single zone systems that don’t use switching relays? My system uses 3 RA832A switching relays and they apparently require the thermostats to be set at 0.4 amps. At least, that’s what I understand from the first picture below.

I also took a few pics showing different thermostats in a 1965 Honeywell Tradeline catalog and a picture of a few more thermostats I have.