Heat Pump Question

[ronto]

For example, the thermostat is set at 65 all the time, the outside daytime temperature is +35. At night the outside temperature drops to +10. By the time morning comes the temperature in the house drops to 50. Meanwhile the heat pump is running non stop (except to deice) all night long.
As the outside temperature slowly rises back to +35 the next day, the temperature in the house slowly rises back to 65 by about 2 o'clock in the afternoon with the heat pump continually running.
Any idea what the problem is would be greatly appreciated...Thank you!

 

[H.H. Hipshot]

Either not enough capacity in the heat pump, or not enough insulation in the outside walls, attic, and windows of the house, or both.

Any heating system can only handle a certain load. My heat pump runs constantly to maintain 65 degrees inside when the temperature outside reaches 32F. I have a very leaky and poorly insulated house, with cracks in and around doors, and single pane glass windows.

My solution is to put on a sweater or light jacket, warm socks and pants.

HHH

 

[Xsales]

The system is not keeping up

Have an AC tech check the freon levels - either low or has a leak

 

[JFB]

does your system have supplimental heating? which would be electrical strip heaters when the outside drops and there is no heat to pump

 

[Pat-inCO]

Close the doors and windows.

 

[Mike J]

I have a heat pump unit in my house. It has heat strips to help for when it can't keep up. That & I have a fireplace so when it gets cold enough the heat pump can't handle it I burn to help it out.

 

[CoolLogic]

Heat pumps, especially older ones, do not heat well when the outdoor temp drops below about 25 degrees. They typically use supplemental heat, electric strips or gas, when your house temp drops about two degrees below set point. It sounds like your supplemental heat is not working. If your refrigerant was low your outdoor unit would be a big block of ice. You can check the supplemental heat by raising your set point about 5 degrees while the outdoor unit is running. You should feel a noticeable rise in the discharge temp.
25 degrees is not an extreme temp for a household system to handle. Has the system been able to keep up in the past? If so then something is broke. You need a tech to check it out.

 

[GunnyGene]

A couple questions. Have you checked the filter? They should be replaced at least twice a year. Do you hose out the heat pump regularly and keep it clear of any debris, tall grass or weeds? You should, if don't already.

 

[coach]

Ditto about auxiliary heat when the temps drop below about 30 degrees. You may have the electric strips, but they may not be working. Could be a thermostat problem or at the unit or a breaker. I would get a tech in to see what the problem is. I've had heat pumps and don't care for them, but sometimes you don't have a choice. The newer ones work better. Life span isn't much longer than about 20 years or so.

 

[blume357]

Yep, I've been told heat pumps stop working somewhere in the low 30's and the auxiliary heat strips come on... sounds like they aren't working... which from a financial standpoint is probably a good thing.

We installed mini-splits in our house over the past year for AC in the summer and 'supplemental' heat in the winter and these critters are good down to somewhere around 10 or lower... but they are different in that there are individual units in each room that run off one compressor (heat pump) outside... no duct work.

 

[Number9]

Sounds like your auxiliary/supplemental heat is not working.
One way to check is to place the thermostat in the aux/emergency heat setting and see if you're getting heat... this setting turns off the heat pump(outside fan and compressor doesn't run).

 

[Fox Mike]

My heat pump is set to initiate the oil fired furnace whenever the temperature drops below 34 degrees. If your house is getting colder than the set temperature then you have a problem somewhere. A call to your heat pump service is needed.

 

[gtxmonte]

I agree with Hipshot...........The unit is too small or the house is leaky. Losing 15* over the course of the night is a LOT. Been in the teens here for a couple days. I have a heat pump. Inside temp on 68*, unit kicks on about every 15 or 20 minutes. Strip heat hasn't been on

 

[caryc]

does your system have supplimental heating? which would be electrical strip heaters when the outside drops and there is no heat to pump

Heat pumps always have heat to suck out of the air. The only way they won't work is if they experience "absolute cold". None of you live in an area where you would experience absolute cold. If you did you would be dead.

I saw a program on TV about that once. I forget what the temp was at absolute cold but it is really freaky. I think it's actually called absolute zero.

Think about it this way. Between absolute zero and regular zero there has to be heat in there somewhere. That's what a heat pump sucks out.

 

[coach]

The efficiency of heat pumps drop as the temperature gets lower. At around 30 degrees most heat pumps can barely keep up and need a supplemental heat source to keep a house comfortable. That's why ground source heat pumps are so efficient since the ground temperature is about 55 degrees. Heat pumps are semi-complex pieces of equipment and can develop problems in many different ways. At a 10 degree outside temp no heat pump can keep up without supplemental heat.

 

[rugnelli]

Air source or ground source... In general, air source performance is poor below 32 degrees while ground source is designed to work with fluid temperatures in the 20's. Closed loop ground source systems have antifreeze in the loop and actually will freeze the ground around the loop. They work well in cold climates. It was 25 below a few weeks ago around here and my parents' house was warm without the need for auxiliary heat.

 

[Jimbo357mag]

Check the breaker box for a tripped circuit breaker and get out the electric blanket.

 

[H.H. Hipshot]

RonT,

Just doing some calculations on your system as it stands currently.
With an outside temp of 35 and inside of 65, your system has the capacity to maintain a 30 degree differential.
When the outside temp drops to 10 and the inside drops to 50, the differential is 40 degrees. This reflects the reduced capacity of the heat pump to pull heat out of the outside air at the lower temp (there is less heat to draw from).

I am no expert, but it seems that your heat pump is working, but as others have noted, your auxiliary/emergency heating elements may not be turning on. These are simply either heater coils or rods like you find in space heaters or ovens, and are positioned in the air stream. They typically operate on 240VAC, and have their own separate circuit breaker.

Some areas of my house get cold no matter what I set the thermostat for, and I have a portable electric heater to warm those spots when there are people present.

Let us know what you find out.

HHH

 

[powder smoke]

Fact is heat pumps work OK But Are Not Suited For LOW TEMP cut and dry.
Heat Pumps become very inefficient when temps fall below 45.

A sales person sells, many have been taken to the cleaners on their claims. The draw
heat out of the air it's not rocket science were dealing with here. The absence of heat is
exactly that!.

Remolded a Lawyer office pretty large project the Mechanical Engineer spec out two massive heat pumps for cooling and heat. When winter came they ran continuously
and could not keep the building above 50. This was a total gut job insulated to the hilt.
To Resolve the the issue back to the drawing board, electric heat coils installed in both
air handler to pick up the slack. End result very expensive way to heat.

Heat pumps have their place and it is not in cold climates. ps

 

[375supermag]

Hi...
I have had a heat pump in my house since I built it back in 1994. It gets serviced every year and is working as designed.
They do not work very well under about 25F in my experience.
We use supplemental heat sources when it gets really cold, either an electric fireplace or a kerosene heater.

Due to my ongoing illness and having two rather rambunctious Lab puppies in the house we aren't using the kerosene heater this winter.

 

[gtxmonte]

It's funny to hear all these people saying a heat pump won't do this and won't do that.............yet mine does it just fine. Now if I lived in a more northern climate, no, a heat pump wouldn't be my choice, but to say they won't work under 25*...........some even said 45* is not correct. I Live in north Alabama, right at the TN line. Hardly arctic cold, but we generally have a month or so when it's pretty cold, into teens and single digits. My unit keeps my house at whatever temp I set it to and does so WITHOUT turning the heat strips on. My aux heating does not kick on unless the temp gets low and stays there.............like teens. It is extremely easy to tell when the heat strips kick on for the first time each year, if they do. You smell them. The coils get dusty and when they kick on, it has a different smell until they burn off

 

[Number9]

It got down to 9 degrees this morning...

Along about 5:00, I heard a banging noise coming from the back steps!

It was the heat pump trying to get into the house! :shock:

 

[ronto]

Today I put the "emergency heat" on which cuts out the heat pump and turns on the heating strips and heat comes out of the vents which means they are working. It appears that the heat pump is not communicating with the heat strips to come on when the heat pump can't keep up with the demand. Is there a relay or something that tells the strips to come on?

 

[Cholo]

gtxmonte, I don't get it either :? It got down to 11* here last night and my heat pump has kept up, and even cycled, all day and it's still only 30* outside. I believe if mine goes 3* lower than I set it, the aux. heat comes on, it hasn't. It's why I never raise the temp more than 2* at a time.

 

[CoolLogic]

RonT, it sounds like your heat pump and supplemental heat are both working which is good. Bringing on the supplemental heat is a function of the thermostat. Usually it will bring on the heat when the space temp drops 3 degrees below set point. Some of the newer tstats allow for the supplemental heat to be locked out. Some also allow locking out the heat pump heat. If you have a newer tstat look up the owners manual on line. If it is an older model that is very simple you may just want to replace it.

CoolLogic

 

[getregistered]

FOSSIL FUEL RULES....

 

[rugnelli]

Again, two types of heat pumps, air source (Southern climates) and ground source (Northern climates).

 

[nlocke]

A stand alone heat pump without auxilliary heat can only raise the air temperature 20 degrees +or- from the outside air. This means that if you want 65 degrees inside, 45 degree outside air is close to the optimum efficiency for your application. Below that, the heat pump will not keep up and you need to supplement the heat with another source. Normally, this is done with electric resistance heat mounted in the indoor heat exchanger.

If it then does not keep up, one or two things are likely the cause. (1) Either the structure does not have sufficient insulation and you're losing heat faster than it can be replaced or, (2) one or more of the auxilliary heat elements are not working. This is not uncommon.

Having worked for an electric utility for 34 years in the Northeast, I've seen and investigated all types of heat pump problems, and unless you live in Florida, the heat pump for cold climate is marginal at best. The only real advantage with it is the AC.

 

[CGDustDevil]

It got down to 9 degrees this morning...

Along about 5:00, I heard a banging noise coming from the back steps!

It was the heat pump trying to get into the house! :shock:

LOL!!!!!!!

They do set up quite a clatter when they're deicing, don't they?!

 

[Number9]

It got down to 9 degrees this morning...

Along about 5:00, I heard a banging noise coming from the back steps!

It was the heat pump trying to get into the house! :shock:

LOL!!!!!!!

They do set up quite a clatter when they're deicing, don't they?!

That's because both heat and cooling are running at the same time... 4-way goes to cooling... aux heat comes in to off-set the cooling... outside fan stops...homeowner calls service department... thinking steam is smoke!