I installed an RTH2300 this winter to replace an old mercury thermostat. It worked fine for the heating season. I turned it to Cool for the first time today and my AC and furnace blower will not turn off. Keeps cooling even though I have it set at 80 degreess and the temperature reads 76.

Be sure it is wired for heat pump rather than conventional and also tstat has been told it is operating a heat pump in the settings menu.

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It's either been rewired wrong or do you have a heat pump and this new thermostat no being compatible?

Your tstat is not the problem. I've not yet worked on an oil furnace. I'm way down south. But either way, if your tstat was calling for heat(heat on), and you pushed a reset at the furnace, more than likely that reset is a safety. OK to reset, but now what ever that safety is preventing from happening, has failed and can not be reset until repaired. The reset should be an automatically opening switch upon unsafe operation. And manually closed to "reset" the safety. That safety is connected to something that is not working properly. Hope this helps!

Hi Kathi,

I think its thermostat or ,thermo sensor is out of order and if it is controlled by electronic circuit it can be faulty.
another thing sometimes output contact relay for motor is faulty it want turn off itself when the circuit energize the coil.

please call electrician who can handle.

regards,
nuwan.

It's official website to check it

curcuit board issues.

?? Connect Wires 5.

Labels don't match?

If a wire does not match any terminal on the thermostat,

see next page.

Quick Installation Guide

6

Alternate Wiring

If a labeled wire does not match any terminal

designation, see diagram below.

Do not use C, C1 or X wire. Do not use B wire if you already

have O wire. Wrap bare end of wire with electrical tape.

This thermostat cannot be used if your old thermostat had

any two of the following wires: R, RC, RH, 4 and V.

Place a jumper (piece of wire) between Y and W if you have

a heat pump without auxiliary/back-up heat.

?? Connect Wires (cont'd)

Programmable Thermostat RTH2300

7

Set jumper JP1, on the back of the thermostat, if you

have connected a wire to the G terminal.

Incorrect jumper setting: An incorrect setting is

noticeable in a gas or oil heating system. When heating

starts, you will initially feel cold air coming out of the vents

as the fan is running before the furnace has enough time

to heat up the air.

?? Set Heating Fan Control 6.

HG Leave the jumper in this factory-set

position if you have a gas or oil furnace.

HE Place the jumper to this position if you

have an electric furnace.

JP1

Quick Installation Guide

8

Set jumper JP2, on the back of the thermostat, if you

have a heat pump.

Incorrect jumper setting: The heat pump operation

will be reversed, i.e., it will cool in Heat mode and will

heat in Cool mode.

?? Set Heat Pump Reversing Valve 7.

O Leave the jumper in this factory-set

position if you have connected O wire to

the O/B terminal.

B Place the jumper to this position if you

have connected B wire to the O/B terminal.

JP2

Programmable Thermostat RTH2300

9

1) Install 2 AAA

batteries on the

back of the

thermostat.

2) Align the two

brackets on the

top of the

thermostat with

the corresponding

slots on the top of

the wallplate.

3) Push the

thermostat

against the

wallplate.

4) Tighten the screw

at the bottom of

the thermostat.

5) Turn power back

on at the heating/

cooling system.

New furnace and new thermostat. The new thermostat is digital and it will not go above 67. It's a Honeywell RTH2300.

usually you should have 4 or 5 wires....if you have AC then this wire should be Y if not was it connected at all before?...Heating requires only R&W

try to get one that is made for oil heat, the installation is easy only two wires, and the instructions make it easy.