Heat pump and Emergency pump are both on, what is wrong?

Problems related to residential installations.

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Heat pump and Emergency pump are both on, what is wrong?

Post by hunterkey » Tue Feb 15, 2011 4:17 pm

Let me start off by saying, I am new to the forum.
I am in the process of purchasing a house, and we had an inspection conducted two days ago and we found there to be a problem with the emergency heat supply.
I live in North Georgia and the outside temperature dips into the twenties sometime during the winter months, which seems to be when I would want to use the emergency electrical heater.
I am trying to educate myself more on HVAC systems, so please forgive me for being so ignorant, this is what the inspector sent me,

The heating, ventilation and air conditioning system (HVAC) is composed of one 2.5-Ton Heat Pump with electric back-up, emergency heat. The furnace is located in the attic. Two thermostats control zone valves to supply heating and cooling separately to each floor.
The attic insulation appeared to be more than adequate with an average ~16 inch depth, and properly installed.
The filter is in the upstairs hallway ceiling (it was very dirty). There is a slot for an additional filter in the unit in the attic.
There is one problem that should be resolved to insure efficient -
This system has emergency electric back-up heat in case the outside temperature goes below 30°F or 35°F, the electric heat will automatically come on to maintain comfortable temperatures in the house. During the testing of the heat, in heat pump mode I noticed the supply temperature was unusually high at ~ 150°F.
There are two reasons why these high temperatures will occur when the outside temp is ~45°F. Either the Heat Pump is extremely efficient or the electric heat was on at the same time. I suspect the latter, because when I placed the downstairs thermostat in emergency heat mode, the supply air temperature dropped to room temperature. In other words, the electric heat alone would not operate.

I figured, I would post this to the forum, seeking help and advice.
Any help would be much appreciated, thanks!

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- Heat pump and Emergency pump are both on, what is wrong?

Post by hvacman77 » Mon Mar 14, 2011 10:55 pm

You could also have a bad outdoor ambient sensor at the outdoor unit. Or a bad coil sensor, whichever your unit uses...

Check the resistance readings for the sensor per manufacturer..

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Joined: Mon Apr 11, 2011 1:15 am

change coil

Post by dpfoc.ragib » Mon Apr 11, 2011 2:16 am

My suggestion is for you that just change your coil after that you will get desired result
Tell me if your problem solved
Air Conditioning Hampshire

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