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

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

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

I have a Weil-McLain hot water boiler for baseboard heat. The system has one circulator pump. The system has 5 zones - 3 work fine and two are not working. All the zone valves and thermostats are...


Hello.Prob#1 valve has a bad END SWITCH,change the power head,thad brings the circ on when open.Prob#2 try manual overide lever.iS IT TIGHT OR SMOOTH?DOES IT JUMP/SNAP?motor very hot? all bad signs.Change that power head too.The transformers are OK because 1 trans can only run 3 valves max.

Sep 20, 2010 | Honeywell (CT62B1015) Baseboard Heater

1 Answer

My honeywell timer for the back boiler heating is blank


need to contact the people who worked on it yesterday to come back and look at it again because it sounds like you have no power to now.

Jan 29, 2010 | Honeywell CT3600 7 Day Electronic...

1 Answer

Temperature fluctuates


Actually that thermostat is adjustable for only +/- 1 degree. I would make sure it is located close to a radiator/register, whichever you have, to help close that 8 degree variance. The thing about hot water heat is that even when the boiler shuts down those radiators are still putting off heat, so the temp can still shoot up a few more degrees after the stat has been satisfied. Is the boiler shutting down when the stat hits 71* ? If not then the stat may be bad. Honeywell carries a 5 year replacement warranty on that stat. I use the Honeywell Focus stats in almost all my installations. They are a very dependable thermostat. Feel free to ask anything else that will help solve your problem...Rob

Dec 16, 2009 | Honeywell Focus 6300B 5-2 Days...

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

Need to wire thermostat


one wire to R the other to W (or W1). Dosent matter which is which

Oct 17, 2009 | Honeywell Electronic Programmable...

1 Answer

I want to replace programmable thermostat with old dial style


The terminals should be the same on both thermostats, except for C- common.
R- usually RED, goes to hot side of transformer,
W- usually WHITE, goes to heat
Y- usually YELLOW goes to outdoor unit
G- usually GREEN goes to furnace blower
Any of the other wires just cap them off you don't need them. If you have an Rh and Rc terminal instead of R and don't have them on the programmable then put a jumper from Rh ro Rc.
If you need more, then let me know what terminals you have on both t'stats and brand of furnace and AC, if you have a heatpump then there's more wires let me know.

Oct 13, 2009 | Honeywell CT87B ROUND HEATING&COOLING...

1 Answer

TOO HOT


not sure how you system is set up but it almost sounds like you have a maintain system or a stuck thermostat to stop the heat if you dont make hot water with this boiler turn off the switch on boiler till you can get service person in if you can tell me more about the way your system is set up i could help more.if you want to see if its a problem with thermostat pull red wire from subbase

May 02, 2009 | Honeywell Electronic Programmable...

Not finding what you are looking for?
Heaters Logo

407 people viewed this question

Ask a Question

Usually answered in minutes!

Top Honeywell Heaters Experts

Sean

Level 2 Expert

77 Answers

Gareth Cockram
Gareth Cockram

Level 3 Expert

657 Answers

yadayada
yadayada

Level 3 Expert

61037 Answers

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

Answer questions

Manuals & User Guides

Loading...