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BillyHvac, Journeyman HVAC Tech
Category: HVAC
Satisfied Customers: 22541
Experience:  Endorsed for unlimited heating, cooling, oil burners, boilers, refrigeration, hydronics
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, Replacing my old manual thermostat with a

Customer Question

Customer: You there?
JA: Thanks. Can you give me any more details about your issue?
Customer: Replacing my old manual thermostat with a Honeywell rthl2510 programmable thermostat. Carrier split unit, gas heat. Everything worked fine. Connected wires as they were connected on the original thermostat. Conneced B G Y and R White was not connected on the original thermostat.
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Customer: YesAC worked find. However, when switched to heat, the heat will not stop on set point. Heat will not turnoff. I disconnected the Blue wire from the B terminal and reinstalled thero. Thermo says heat on, but heat does not come on. You can switch fan to on and fan comes on, but no heat.
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Submitted: 1 year ago.
Category: HVAC
Expert:  HVAC Guru replied 1 year ago.

Hello and thanks for using this service, if you have been waiting do not worry or get upset I am just one of the techs on here and I try to get to as many customers as I can and I just picked up your question now. Please give me time to respond sometimes I get your replies late so there may be a delay in my response.

Did you go into the setup mode on the thermostat and make sure you selected the system you have?

Customer: replied 1 year ago.
Options on setup were correct as default. I do not have a heat pump.
Expert:  HVAC Guru replied 1 year ago.

If you do not have a heat pump you said you have a wire connected to the B terminal?

Customer: replied 1 year ago.
I did yes but after reviewing the install guide I disconnected the B wire. Now NO heat comes on Thermostat says heat on but fan never kicks on.
Customer: replied 1 year ago.
I now only have 3 wires connected. G Y and R
Customer: replied 1 year ago.
AC works fine.
Expert:  HVAC Guru replied 1 year ago.

Connect the B wire to the W terminal and try it. It should heat.

We are on the honor system for our time, all I ask is please rate my service using the STAR RATING LINK on your page before you leave. If you are not happy with the service please let me know before leaving a negative rating. This is the only way I am paid or credited through the site for my time. This will also allow you to get directly back to me for FREE follow up questions and tips are greatly appreciated! Thanks

Customer: replied 1 year ago.
Heat came on. Testing set point shutoff now
Customer: replied 1 year ago.
Unit shut off at setpoint. You have answered my question. Where do I rate you?
Expert:  BillyHvac replied 1 year ago.

sorry for the delay in someone getting back to you.

Is the thermostat still functioning as it should?

The B terminal is an accessory terminal to Win heat mode. So both will work. Moving the B wire to W simply calls for heat from another terminal.

On your system just leave

red to r

yellow to y

green to g

and the B to w

If you need to rate service you will find it at the top of the page with a 5 level rating system.

Thank you.