Honeywell Heating & Cooling - Recent Questions, Troubleshooting & Support


Need help replacing a thermostat

If you have wifi try the Hive Thermostat. Control your heating off your iPhone or with a touch of the button on the remote controller. Otherwise there are many hard wired systems available. Have a look here;
8/20/2023 7:07:10 AM • Honeywell... • Answered on Aug 20, 2023

I have lost all power to my Honeywell ST699 timer

I'm sorry to hear about the issue with your Honeywell ST699 timer. Here are a few troubleshooting steps you can try to resolve the problem:
  1. Check the power supply: Ensure that the power is still on in your home or building. Check the circuit breaker or fuse box to see if any switches have tripped or fuses have blown. If necessary, reset the circuit breaker or replace the fuse.
  2. Check the timer's power connection: Ensure that the timer is properly connected to the power supply. Double-check the wiring connections to make sure they are secure and not loose. Also, check if there is any visible damage to the wires.
  3. Check the battery: If your ST699 timer has a backup battery, make sure it is not dead or discharged. Replace the battery if necessary, following the manufacturer's instructions.
  4. Reset the timer: Sometimes resetting the timer can resolve technical issues. Locate the reset button or refer to the user manual to find out how to reset your specific timer model.
  5. Call a professional: If the above steps do not resolve the issue, it may be necessary to call a professional electrician or the Honeywell customer support for further assistance. They will be able to diagnose the problem and provide a solution.
Remember to always exercise caution and follow safety guidelines when working with electrical components. If you are not comfortable or familiar with electrical work, it's best to contact a professional.
8/2/2023 2:15:53 AM • Honeywell... • Answered on Aug 02, 2023

Honeywell HT908 WIRING diagram?

You may find some help on the following page: You might inquire in the chat at Honeywell whether the following would be helpful:
6/26/2023 5:51:25 AM • Honeywell... • Answered on Jun 26, 2023

AC Unit not turning on and Honeywell Thermostat not powering on

no info generic answer check and test transformer or reset in air handler
6/17/2023 12:02:46 AM • Honeywell... • Answered on Jun 17, 2023

ST9400 Lights Staying on. I've turned them off and on but no difference

Hi, You can factory reset the wall control and then input the current date and time. This should fix the issue as it's the most noticeable problem from what you're describing. Thank you.
4/24/2023 9:23:49 AM • Honeywell... • Answered on Apr 24, 2023

I have a Honeywell non programmable thermostat. Two zone boiler in floor system. Neither of the thermostats are showing any digital display and can't be turned on. Any ideas?

No high voltage, bad transformer, blown fuse, tripped float switch, bad tstat. If you need further help, reach me via phone at
3/18/2023 5:44:15 PM • Honeywell... • Answered on Mar 18, 2023

The boiler stopped reacting to HCW80 thermostat communication OK but works from the kitchen floor sensor

If your boiler is not reacting to the HCW80 thermostat, but is still working with the floor sensor in the kitchen, there may be an issue with the thermostat itself or its connection to the boiler. Here are some steps you can take to troubleshoot the issue:
  1. Check the thermostat: Ensure that the thermostat is set to the desired temperature and mode (e.g. heating mode). You can also try replacing the batteries if applicable.
  2. Check the wiring: Verify that the wiring between the thermostat and boiler is securely connected and not damaged. You can refer to the thermostat and boiler manuals for wiring diagrams.
  3. Check the thermostat settings: Some thermostats have settings that may need to be configured properly, such as the communication protocol and wiring mode. Refer to the thermostat manual for guidance on these settings.
  4. Reset the thermostat: Try resetting the thermostat to its default settings to see if this resolves the issue.
  5. Contact a professional: If the above steps do not resolve the issue, you may need to contact a professional HVAC technician to diagnose and repair the problem. They will be able to inspect the thermostat and boiler system and identify any issues that may be causing the problem you are experiencing.
3/18/2023 2:47:22 PM • Honeywell... • Answered on Mar 18, 2023

I have no power to my Honeywell thermostats or my Honeywell hz311 zone controller and the fuse is not blown

A mon avis, vous n'avez pas d'alimentation sur vos thermostats Honeywell ou votre contr?leur de zone Honeywell hz311 et que le fusible n'est pas grill?, il y a probablement un autre probl?me ?lectrique ? r?soudre. Voici quelques ?tapes que vous pouvez suivre pour d?panner ce probl?me V?rifiez le disjoncteur : Assurez-vous que le disjoncteur pour votre syst?me de chauffage et de refroidissement n'a pas saut?. Si c'est le cas, r?enclenchez-le et v?rifiez si l'alimentation est r?tablie. V?rifiez les connexions de c?blage : V?rifiez les connexions de c?blage ? votre contr?leur de zone Honeywell hz311 et ? vos thermostats Honeywell. Assurez-vous qu'ils sont tous bien branch?s et que les fils ne sont pas desserr?s ou endommag?s. V?rifiez les transformateurs : V?rifiez les transformateurs dans votre syst?me de chauffage et de refroidissement. Si les transformateurs sont d?fectueux, ils ne pourront pas fournir l'alimentation n?cessaire ? votre syst?me. Remplacez les transformateurs si n?cessaire. V?rifiez tout de m?me les fusibles sur les transformateurs : V?rifiez les fusibles sur les transformateurs et remplacez-les si n?cessaire. Contactez un professionnel : Si vous ne parvenez pas ? r?soudre le probl?me, il est peut-?tre temps de contacter un professionnel qualifi? pour examiner votre syst?me et diagnostiquer le probl?me. Il est important de prendre des pr?cautions de s?curit? lors de la manipulation de tout syst?me ?lectrique. Veuillez contacter un professionnel pour vous aider ? r?soudre le probl?me. Si vous n'?tes pas s?r de ce que vous faites.
2/25/2023 6:27:43 PM • Honeywell... • Answered on Feb 25, 2023

Honeywell thermostat LR95329 problems

If your Honeywell thermostat LR95329 is providing heat but not air conditioning, there could be a few different reasons why. The fact that the fan operates in fan mode indicates that the issue is likely related to the A/C function of the thermostat. Here are some steps you can take to troubleshoot the problem: Check the wiring: Make sure the wiring connections for the A/C are secure and in the correct position. Verify that the wires for the R/Y and R/W connections are properly connected and not damaged. Check the transformer: A faulty transformer can cause issues with both the heat and A/C functions of the thermostat. Check the voltage at the transformer to ensure it is providing the proper amount of power. The voltage should be between 24 and 30 volts. Check the circuit board: If the wiring and transformer are functioning properly, the issue may be with the circuit board. Inspect the circuit board for any signs of damage or wear, such as burn marks or loose connections. Contact a professional: If you are unable to resolve the issue on your own, it may be necessary to contact a professional HVAC technician to diagnose and repair the problem. It's also worth noting that the voltage readings you provided to customer service are within an acceptable range for the R/Y and R/W connections. The R/G reading is slightly lower, but this is likely due to the fact that the fan is drawing some of the voltage.
2/24/2023 9:01:05 AM • Honeywell... • Answered on Feb 24, 2023

I JUST PURCHASED a honeywell LR 95329 thermostat. I can't get the AC to come on.

It sounds like there may be an issue with the wiring or configuration of your Honeywell LR 95329 thermostat. Here are a few things you can check:
  1. Make sure that the thermostat is properly wired. Double-check the wiring connections for the cooling mode (usually the yellow wire) and make sure it is securely connected to the corresponding terminal on the thermostat.
  2. Check the configuration settings of the thermostat. Ensure that the thermostat is configured for cooling mode and that the temperature is set to a temperature lower than the current room temperature.
  3. Verify that the air conditioning unit is working properly. Check to see if the unit is receiving power and that all the connections are secure.
  4. It's also possible that the thermostat is defective. If you've verified that everything else is working properly, you may want to consider contacting Honeywell customer support for further assistance or consider consulting with a licensed HVAC technician.
2/23/2023 4:27:48 AM • Honeywell... • Answered on Feb 23, 2023

Honeywell TH6000 series thermostat does not turn Fan on.

It's one of two issues; either the wiring to the thermostat is incorrect, or possibly you have an open ground. Depending on your system the wires at the thermostat end might have to pair up on one lead. go to where your unit is and look at the schematic for the control board, it will let you know what color you are looking for on the blower lead -- then make sure the corresponding color matches at the thermostat. Knowing the make and model of you unit and the board on it would allow me to be more specific, hope this helps you out some in the meantime.
2/6/2023 10:27:07 PM • Honeywell Focus... • Answered on Feb 06, 2023

Red LED on honeywell r6660d

The problem is that the 2 units are "not speaking to each other". this could be caused by low batteries or a loss in signal caused by a powercut or an objection in the way of the 2 units.

first you need to turn the power off to the r666od (or otherwise known as the HC60NG) for 10 secs, then turn back on. then hold the grey button in for 15 secs. release then hold in for a further 5 secs.

go to the honeywell cm61 press the off button. hold temp up. temp down and prog 1 in for 3 secs until the dipslay goes to INST. at this point release all 3 buttons then press the i button until a beacon starts flashing.

this is now the end to your problem.

N.B the reason the green light was on is because the man override button will have been pressed.

hope this helps
1/28/2023 11:44:53 PM • Honeywell... • Answered on Jan 28, 2023

How do I reset all

How do I override settings on a Honeywell thermostat RTH221B
1/28/2023 5:51:47 PM • Honeywell... • Answered on Jan 28, 2023

Honeywell Thermostat RTH230B does not call for heat

It sounds like it's wired correctly given you can operated it manually. Is this a new thermostat? Has the program function ever worked? Ensure you have the current date/time including am/pm set properly so the program understands it's starting point. If that's not the issue try setting your temperature set points to extremes. If that enables your HVAC to react it means your temperature sensor is failing.
1/19/2023 6:03:35 PM • Honeywell... • Answered on Jan 19, 2023

Gas Rayburn Nouvelle it has a new Honeywell gas valve V4600C and thermocouple fitted. ,Inlet pressure 28 outlet trips grey. start button after 10 mins.

limited info generic answer ---is the pilot lighting and holding when calling for heat does gas light unit then go out that would be a s--afety shutting it down [[[high limit--fan-dirty filters -improper install -etc ]]]---if your familiar with gas systems proceed and test the circuits if unfamiliar have gas or repair company come and evaluate
1/16/2023 3:11:19 PM • Honeywell... • Answered on Jan 16, 2023

Honeywell TZ4 - all 4 zone lights green, when called for cool, Cool light turns green then quickly turns off with clicking sound. AC#1 clicks but will not turn on and no humming observed,

It sounds like there may be an issue with the Honeywell TZ4 thermostat and the cooling system connected to it. Based on your description, it appears that when the thermostat calls for cool, the cool light turns green briefly, then turns off with a clicking sound. Additionally, the first air conditioner unit clicks but does not turn on, and the outdoor unit clicks, the fan moves for a second, then stops. This could be caused by a variety of issues, including a malfunctioning thermostat, a problem with the wiring between the thermostat and the air conditioner, or a problem with the air conditioner unit itself. To troubleshoot this issue, I would recommend checking the following:
  • Check the wiring between the thermostat and the air conditioner to make sure it's not loose or damaged.
  • Check the thermostat to make sure it's functioning properly.
  • Check the air conditioner unit for any visible damage or malfunction.
  • Check the compressor, it could be a failed compressor that is not running.
If the problem persists after checking these things, it's best to call a professional technician to diagnose and fix the problem as it might require specialized knowledge and skills.
1/15/2023 9:33:54 PM • Honeywell... • Answered on Jan 15, 2023

Honeywell cm921 keeps automaticaly turn target temp to 35 c

The problem you're experiencing with your heating system could be caused by a malfunctioning thermostat. The thermostat may not be properly calibrated, or it could be faulty, causing it to incorrectly read the temperature and turn on the heating when it's not needed. It could also be caused by a problem with the heating system itself, such as a malfunctioning valve or a blocked duct.
1/14/2023 10:58:25 PM • Honeywell... • Answered on Jan 14, 2023

Honeywell Chronotherm IV PLUS thermostat

It must be wired or it will not work. Take a look at the installation instructions before you attempt any reconfiguration! screenshot 2022-12-28 at 17.46.39-undefined-undefined-0.png
12/28/2022 8:16:26 PM • Honeywell... • Answered on Dec 28, 2022
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