Heat Pumps and Electric Heating - Heat Pump back up heat problem

I have a 2008 Ducane 2ton heat pump with a 5kw strip. I don't think the system is using the back up strip when the thermostat falls. Its consistantly 60 degrees in the house in the morning with the thermostat set at 70.

Could this be a thermostat issue? Am I correct in assuming that the back up should automatically kick in when the temp falls?

5KW isn't a lot. How big is your house? Where are you located?

It's been pretty cold in most parts of the country, chances are it's doing all it can do.

What are your capabilities to check some things? Ammeter, or voltmeter?

Its a 1000 sq ft house and I live in Delaware so its been pretty cold. I have lights on the Tstat but they do not light up. I was thinking I have a problem with it.

Yes I have a ammeter and voltmeter

If you have an ammeter, hook it up to one of the wires going into your air handler, turn the tstat up to 1 degree above room temp, take a reading, then bump it up 3 degrees or so above room temp. If the amperage jumps up about 21 amps from the previous reading, then they're working. If not, let us know.

You may be able to tell at your electric meter also. When they kick in the meter will noticeably turn faster. May require 2 people for this one though.

I have a feeling you may have to bump up to 8-10kw, IMHO.

What kind of advice are you giving this guy? If his stat is set to 70 and the best his system can do is 60, he has a bigger problem than just the aux. kicking in. If there is a 10 deg. spread between setpoint and actual temp. his system is not working properly, period.

My advice, get the installer back in to check it out and correct the problem.

Well, first off the heat pump isn't going to do much once the outside temp reaches ~40 degrees.

Since his outdoor temperature is about 21 deg or colder overnight, 1000 sq ft house, don't know about insulation, insulated windows, etc and 5KW strip heat.

If you read it carefully he says "in the morning" he didn't say "all the time" I'm willing to bet at 8 am the temp is starting to come up past 60.

Like right now, his temp is like 30 with a windchill of 20. He's probably already using auxiliary heat and the indoor temp will continue to fall because the aux is undersized.

It doesn't matter what the tstat is set on, if he had set on 61 it still would be 60. So that doesn't mean squat. If it's 100 outside and you set your tstat on 60, do you really think it's gonna reach that? Is there a problem with it? NO

We just had a house here that was remodeled and new HP installed with 5 KW, it wouldn't keep up so it had to be replaced with 8 KW and that house is smaller.

So my advice is a sound hypothesis.

And Yes, you could possibly have a tstat problem.

wirenut? Are you sure you didn't mean wingnut?

Without a load calc, using old rule of thumb, 1000 sqft = 1 1/2 ton.

This guy has a 2 ton.

At 40 ambient a 2 might be 1 1/2 tons.

The stat is set at 70 and it's 60 inside.

The aux aint working either due the stat, heat strip, or defrost board.

I would look at the heat strip myself and stat.

With a 10 delta T strip should be on.

jeepgrady good call, stick around we need you.

Call the installer back, most likely warranty repair.

What do you mean by wingnut?

We're not talking about 40 deg ambient, were talking low 20's.

Regardless that's what we were trying to do is ascertain whether the aux was working.

The guy said he had a fairly new system.
Do you know how old his house is? Do you know if he has insulated windows or not? Do you know if his house is insulated? Do you know if they replace a 1 1/2 ton with a 2 ton and used existing duct work that may be too small,or sheet metal uninsulated? But hey, they made the sale, the system's in and they got paid.

If you look all over this forum, people are constantly having trouble with their "new" systems. Why, because no one wants to take the time to do it right, just slap a system in and get paid. Up north where he is and a 5KW package, please.

There's more to a load calculation that just square footage, and I'll assume you do this for a living.

I don't do this for a living, but I have seen many a system installed incorrectly. As a matter of fact, as stated in an earlier post. Tomorrow, I have to go to a house where a 2 ton 5KW system was installed, upgrade the circuit to the AHU so 8KW strips can be installed because the house can't maintain over 62 overnight. Go figure.

So for you to sit there and try to ridicule me for trying to help the guy out, shows your professionalism, and you're a moderator?Beer 4U2

robrote: Sounds like you do not have a proper size system where you are. A good installer should know for his area and do it right. You definitely need at least a 8kw backup heater but the fact that you have a 60 degree difference says the HP is not functioning properly. I had that problem and after getting a professional (which are hard to find sometimes) found a stopped up drier/ filter in the outside unit along with a bad expansion valve. Check your vent temp and return temp and should be at least 14-17 degree difference. Check the big line at air handler and if it is hot to touch but the small line is cold then you have freon flow problem. That is what mine was doing and after repair the big line was hot and the little line was warm indicating the freon flow was better. What was happening when the freon flow was low the air flow across the coil was virtually absorbing all the heat it could get but when fixed and more freon moving in the lines some heat was returned back through the small line. This line is not insulated and by the time it ges to the outside unit most of the rest of it is lost. On real cold nights say in the 10-20 degree the temp difference between the return and vent is about 17 degrees and on moderate days 30 to 40 it is around 20 to 21 degrees. I have two stages of electric heat with 15kw total. The second stage I leave breaker off for it. With a mechanical Tstat and in normal mode one blub controls the HP and the other the first heat stage. But when in emergency heat mode one bulb contols the first stage and the second then controls the second stage. Took me a while to figure that out. My HP is a 3 Ton heating 2 floors of about 1250 each squrare feet here in Central VA. This is my second unit about 8 years old and had the last several years was slowly dropping effiency. I kept calling the company that put it in and asked me to check the temp difference between return and vent. It was most of the time 10 degrees no matter what the outside temp but ran constantly on cold days. He closed his shop and finally I called a suggested on the side guy reccommended by a friend. He said I was low on freon and added some but never checked the head pressure. I could hear the compressor laboring and shut it off and finally called local professional company. Always make sure their service people do not work on a commision. He is there to fix what you have not to sell a new system. This is what happens to a lot of people. He said the suction indicated low freon but head pressure was saying there not enough freon flow. It took good troubleshooting and it is working better than ever. Sometimes during installation trash is introduced and with the dinky filters some have they stop up quickly. Now I have bidirectional filter/drier on the small line. Ask around about the company that put yours in and you may need to find someone else to fix your system. Warranties can be handled by others but choose wisely. I know some will disagree with me but this is what I learned just observing. I have learned more by accident than ever on purpose and the young tech working on mine said he did on this one.

I have a 2008 Ducane 2ton heat pump with a 5kw strip.

New unit.

Its consistantly 60 degrees in the house in the morning with the thermostat set at 70.
I have lights on the Tstat but they do not light up.

Correct or incorrect sized strip heat, the above 2 statements point to non functioning elec heat.

With stat set at 70 and 60 inside elec heat should be on and aux light on stat should be on.

Check Air Handler for elec heat breaker or fuse.

If a simple solution can't be found, ask for warranty service call.

The last poster is right that your electric heat is not working. If you have a light that indicates when backup heat is on but still no heat support then there is a problem with the heat power. If the light is not on then the TStat is wired wrong. Unless you have very poor insulation or a window open your heat pump should be doing better than it is. Drag the installer back and make him fix it. Sorry was so wordy earlier but I believe when the installation is done right Heat Pumps work. I bet your temps are not much different there than where I live. Guess I was lucky and got someone that knew what he was doing to fix mine.