Ask Me Help Desk - Setting low-temperature cut-out and balance point on Coleman Heat Pump

I have a Coleman HC3B heat pump. The local service technician showed me the jumpers for the low-temperature cut-out (LTCO) and balance point (BP). It appears to be a set of pins with labels decreasing in value by 5 (45, 40, 35, etc.) which I assume are the temperature.

I would like to understand how to set them properly so that my auxiliary heat comes on, for example, at about 35 degrees and the heat pump shuts off at about 25 degrees. The owners, installation, and technical manuals were not helpful.

They were originally set with the jumpers on 30-25 and 20-15, I believe. I interpret this to mean the aux heat comes on at 30 degrees and the heat pump shuts off at 20. Is this correct? The jumpers look identical, so I assume the higher-temp jumper defaults to the BP and the lower-temp is the LTCO.

Thank you!

Setting those jumpers has much to do with where you live (weather conditions) also. It also has to take into consideration the type of home and the heat loss calculation to fine tune the system. The first step is to call the company that installed the unit for you. They are professional HVAC people and should know the ideal settings for your setup. You start playing with the settings and you will end up with a possible ball of ice outside where the HP used to be.

The 3 B series is also a R-410 machine that likes settings a bit different from a 3 A series that is a R-22 machine. The Echelon is a nice unit but keep your hands off and let a profession do the fine adjustments when they visit ON site. Since you bought the unit from a professional company they should be more than willing to consider your request.

A expansion valve if installed instead of a flow piston system will also make a difference in the system performance as well. This also needs to be taken into account for proper settings. That unit also has a service (microprocessor) control that coordinates all the sensors in the unit so it always operates at optimum efficiency.

Last year a person asked just about the same question on another help board. They ended up with one big headache and finally had to call for service when the temperature got very cold. It was a new unit but he had to pay for service since they discovered he changed the settings form when it was installed. If you really have to do this yourself I suggest you attend a Coleman training course. If that is to much trouble for you I suggest letting a pro make the adjustments on site OR leave it alone.

A bit of info for you from the distributer web site.

http://www.colemanac.com/PDFFiles/271551-CTG-B-0908.pdf

Parts you will need some day

http://www.colemanac.com/PDFFiles/03...002-D-1207.pdf

User manual

http://www.colemanac.com/PDFFiles/361822-UUM-A-0208.pdf

Quote:

Originally Posted by hvac1000

The first step is to call the company that installed the unit for you. They are professional HVAC people and should know the ideal settings for your setup. You start playing with the settings and you will end up with a possible ball of ice outside where the HP used to be.

Thanks, hvac

I appreciate the detailed feedback very much.

Unfortunately for me, the "professional" installer turned out to be a real Bozo, and he is out of the picture, but that is another story. We live out in the boonies, and there is not a lot to choose from.

My understanding of HP's is as follows: they lose efficiency as the temperature drops, and at about 25 degrees they give essentially no heat. At the balance point, the auxiliary heat kicks in together with the HP, then when the temp drops to the cut-out the heat is purely aux.

When the unit was installed I requested (naively) that the settings be at their lowest practical value to save propane (my aux). He was a bit vague about setting them precisely, and had to come back a couple times to get them set right. The result was that the heat pump runs alone and a lot longer than I think it should when the outside temp is about 30. My desire was to raise the setting temp of both just a bit, so the aux heat kicks in before the heat pump is no longer efficient.

My present HVAC man seems very good, but was not familiar with the Coleman unit. He pointed out the jumpers to me but did not give any guidance regarding setting them. He did not seem too concerned about me making minor adjustments.

I will take your advice and not monkey with the jumpers without adult supervision. If you happen to know how to interpret the jumpers on this Coleman unit, I would appreciate the knowledge, so I can pass it on to him to set it properly for our area. Otherwise, I can contact Coleman.

Thank you!

Many item I do not post for fear that someone will read it and try to use it on there system when it could be totally wrong info for there system. If you know what I mean. Contact Coleman for there advice as to your settings.

Quote:

Originally Posted by hvac1000

Many item I do not post for fear that someone will read it and try to use it on there system when it could be totally wrong info for there system. If you know what I mean. Contact Coleman for there advice as to your settings.

You give good advice, thank you. I shall do that.

Does your tstat use an outdoor sensor? If so you may be able to configure it to lock-out your HP and run the aux heat to improve your comfort, which I assume is what you're after. If that poses a problem just post your tstat model and we can see what to change.