[bjennings79]

Gentlemen,

I have a 4 year old heat pump that I am trying to troubleshoot. I came down stairs this morning to find that my heater was only producing room temperature air. I went through the basic troubleshooting that I am capable of, which consists of the following.

-Inside blower does come on.
-Inside condenser in the air handler is not warm to touch. (Should it be?)
-Outside HP unit fan and compressor come on.
-Larger copper line (insulated with foam rubber) gets very warm to touch.
-Smaller copper line (uninsulated) is only slightly warm.
-There is no ice, snow, debris, or blockage of any kind on the outside unit.

I am pretty sure that my thermostat has been improperly configured for an unknown amout of time to use a single stage heat pump. I have heating coils inside the air handler and when I reset the thermostat and reprogrammed for a 2 stage heat pump, I started getting hot air. Now my thermostat has an AUX indicator on the display, which I have never noticed before.

How can I be sure that my system is operating properly? I know that the auxiliary heat uses about 3x the energy that the heat pump uses, so I'm worried about it having to run in AUX mode.

This is a Braeburn 5300 thermostat and a Nordyne ft4be-036k 14 seer heat pump. T-stat is set on 72.

 

[bjennings79]

Update - The AUX indicator on the thermostat just went off and the air coming from the register is down to 74 degrees from over 90 degrees when the AUX electric heater was active. Temp at the thermostat is 71, set for 72.

 

[sammy37]

You havent mentioned how cold it is outside, big factor for a heat pump.

 

[bjennings79]

You're right. Could have sworn I put that in. It's been low to high 30s all day. Currently about 37.

 

[beenthere]

Could have a leak in it and be low on charge.

 

[Marty S.]

In the mid 30's a 3 ton heat pump should be putting out around 29,000 BTU.With a blower set at 1200 cfm that means you should be seeing a 22 degree temp rise between return air and supply air.

 

[bjennings79]

Just a little more info after some additional testing.

If I switch over to Cool mode,
-The air temp at the vent does not change
-Suction line outside does not get cold
-The AUX indicator comes on along with the COOL indicator on the t-stat

Starting to wonder if the charge is low, as suggested. I'm also wondering about the reversing valve. If it were stuck, wouldn't it at least do one or the other?

 

[beenthere]

An RV can be stuck in mid postion, and it won't let the system heat or cool.