Question about Honeywell CT87B ROUND HEATING&COOLING MECHANICAL THERMOSTAT - WHITE Heater

2 Answers

Thermostat problem ?

I have a typical gas powered boiler / Heating system (radiators) and use a T87F Honeywell thermostat with 2 wires coming from the thermostat to the boiler (millivolt system). I replaced the thermostat last heating season and did not make any adjustments to the thermostat, however I had to set the temperature guage to 76 degrees to remain comfortable.

The home has a second floor and I currently have the thermostat set to 70 degrees. When the boiler cuts on, the burn time is very short, less than two minutes and sometimes less than a minute. The radiators on the second level rarely have a chance to become warm before the boiler cycles off. I checked the thermostat and the heat anticipator setting is at .4 on the scale. I'm not sure what this means or what the proper setting should be for my system.

The temperature on the thermostat says that the home is at 70 degrees but the upper rooms and the remainder of the house is not 70degrees, they are more like 64 degrees and the heat does not reach the upper floors before the boiler shuts off. Any help would be greatly appreciated. Thanks



Posted by on

  • fairfordmick May 11, 2010

    is there any air in the rads upstairs where is the thermostat located is it near a radiator

×

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 308 Answers

If you start by looking on your gas valve, you should find the correct amperage to set the heat anticipator at. I am not sure if you have a forced hot water system or a steam system, but depending on the case, you may also have a second problem, which is easily addressed. If you have forced hot water, the upstairs baseboard/radiators may be airbound and need to be bleed. If you have steam, you may need to slow down the downstairs valves, and open the upstairs valves to get a balance. Hope this helps

Posted on Jul 09, 2009

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that got 5 achievements.

    Governor:

    An expert whose answer got voted for 20 times.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Expert
  • 82 Answers

I believe the T87 is a round, non programmable...right? When you installed it, did you make sure the mounting bracket was level? This is the flat plastic bracket you screwed into the wall which the thermostat attaches to. The T87 is a mercury thermostat and must be level or it gives a false reading. A "torpedo" level would work best for this as they are only about 8 inches, but you could use a larger one. Take the thermostat off and see if that is the issue. Good luck

Posted on Dec 31, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Hi, I have a baxi solo boiler WM60/4RS and a Landis & Gyr RWB252 timer but my Honeywell T6160 thermostat has nether been connected, can anybody shed light on the wiring connections please.


The color code for thermostat wiring is as follows.
The "R" terminal is power into the stat from the boiler control transformer. Normally 24 volts. The "Y" terminal is for cooling. Normally left blank for a boiler. The "W" terminal is for heat. This one used to start the heating cycle.The "G" terminal is for fan operation. Probably not used for a boiler. Check the boiler terminal board for these functions and write down the wire color on each one. Match the boiler colors to the right function on the stat. If you need more than this, let me know.

Jan 06, 2014 | Honeywell Programmable Thermostat Heater

1 Answer

Heating not working and Honeywell Thermostat Heater states that the temperature is 45 degrees celsius.


without seeing it its hard to say, the thermostat controls the boiler and/or diverter valve depending how its been wired, the diverter valve shunts the water to were its needed ie from one circuit to another if you have two therostats there is a conflict somewere, best bet to have an engineer sort the wireing out

Dec 28, 2011 | Honeywell Programmable Thermostat Heater

1 Answer

IVE GOT A HONEYWELL T87A 3 WIRE THERMOSTAT MOUNTED ON THE WALL AND WHEN I WANT TO TURN ON MY HOT WATER BOILER I HAVE TO LOWER THE T-STAT SETTING INSTEAD OF INCREASING IT TO GET THE HEATING SYSTEM TO TURN...


I would switch to a two wire heating only stat It sounds to me like they have the boiler wired into cooling side. Do you also have to set switch on your t-stat to cooling or leave it on heating. Just curious. I would still go with two wire stat. Thanks.

Nov 11, 2010 | Honeywell CT87B ROUND HEATING&COOLING...

1 Answer

Three wires not marked for new Thermostat!


You will need to go to the heating system and see what color wires are hooked to that. Typically the black and white wires will be used unless they used another color due to a bad wire. Hook the colored wires to the R or RH terminal on the thermostat and the other wire to the W terminal. You can also try taking the wires you have and one by one twisting them together and have a second person inform you when the heating system turns on. Take those two wires and hook them to the terminals I mentioned above.

Jan 14, 2010 | Honeywell Programmable Thermostat Heater

2 Answers

I have a Honeywell Thermostat CM67NG The flame symbol is showing on the thermostat, but there is no heat from radiators. The status code on boiler says there is ' no heat demand'. Boiler shows radiator...


You may have a broken thermostat wire. Disconnect the wires from the thermostat and please note what colors are hooked to which terminals. Cross the R and W wires and see if your heating system turns on. If it does not, you have a broken wire or bad connection at the heating system. If it does start, you have a bad thermostat or bad connection at the thermostat.

Nov 30, 2009 | Honeywell Programmable Thermostat Heater

1 Answer

Need to wire a honeywell RTH7400D thermostat to 3 wire hot water


Just mark the old wires on the old thermnostat...R , W etc...and put them on the same terminals on the new 1.....also there should be some adjustment ire : switch on the back or under the cover to adjust for Hot water heating or electric heat...either is the setting you should have it on....also you shouldn't setback the thermostat at night or when away very much....2 degrees is fine , as the boiler will run along time to raise the temperature in the morning and may not get there by the set time

Oct 18, 2009 | Honeywell Electronic Programmable...

1 Answer

Honeywell round thermostat Model #T87F continuously running


you either have 2 thermostat wires bare and touching or a zone valve stuck open

Feb 28, 2009 | Honeywell Programmable Thermostat Heater

1 Answer

Installing CM900 Honeywell into Junior 24 Bosch Combi


What kind of boiler are using is this boiler a on the demand electric or gas? You need low voltage wires. If you get me make and model # of off boiler i can try and find wiring diagram . Tell me a little more about you heat system to. Like baseboard heat or in floor how many zones

Jan 16, 2009 | Honeywell Programmable Thermostat Heater

Not finding what you are looking for?
Heating & Cooling Logo

409 people viewed this question

Ask a Question

Usually answered in minutes!

Top Honeywell Heating & Cooling Experts

Bill Long

Level 3 Expert

587 Answers

paulcarew

Level 3 Expert

2303 Answers

Brandon Berry
Brandon Berry

Level 2 Expert

407 Answers

Are you a Honeywell Heating and Cooling Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...