It is not normal for the GSHP to run that much. Mine only runs for 10-15 minutes an hour. How big is your house? How well insulated is it? What were the results of the heat loss calcs?  Who installed your system?

The house is about 2200sq' (heated) consisting of a main & top floor that is of gable design. If you include the basement that is below grade and has NO heating registers (not heated) it comes in right at 3000sq'

Insulation is fairly good, however we are in need of some new windows, which is slated for this next spring.

The old propane furnace, which I understand put out hotter air, did shut off after a while and stayed off for some time before coming back on... I would expect that the same happened with the geothermal but that it should have longer run times because of the cooler air.

Jordan

How hot is the air coming out of your registers? Any idea what the temp is on the water coming out of your ground loop?

I moved my "Outside" temperature sensor for the Honeywell thermostat and placed it INSIDE the hot air duct that is leaving the furnace...

I can only assume that the air going into the furnace is at the temperature reported by the thermostat upstairs (should be a no-brainer).

Air going into the furnace is at 69* and air comming out of the furnace is at 81*.

The furnace is operating in ints y1 first stage... I verified with my volt-meter.

I forced the furnace into 2nd stage (Y1 and Y2) by turning up the thermostat to 75* and the temperature being produced (after about 10 minutes) has worked its way up to 95*
Surely the temperatures should be greater than this right?

I haven't yet figured out a way to measure the ground loop temp yet... I'll see about picking up some thermisters this weekend.

Thanks for your help.

Jordan

Perhaps I should mention that the furnace is a HydreHeat Mega-Tek and has only been in service for 14 days and it has been in the 70's for 8 of those days.

Jordan

Something is not right. I have a Florida Heat Pump 4.5 ton. Single Stage. I get 110° air off the top of my unit and 101° air coming out of my ducts.
Most two stage units turn on the second stage if the first stage runs for so many minutes. What kind of thermostat are you using? Who installed and wired your unit?
Who did you buy the unit from? The first thing I would do is get the controls set so that second stage heat comes on after the unit runs for 3 minutes. This is usually done on a programmable thermostat.

I am not sure why you are only getting 95° air. Is this measured at the top of the heat pump or at a register?

There is a user on these forums called Megatek. He works for Hydro Heat. You might try contacting him and see if you should be getting warmer air from your GSHP.

The thermostat is a honeywell 8000. I have scoured the setup manual and verified it against the setup of the thermostat. I do not see any particular setting that I am certain dictates the 3 minute 1st stage and then kick up to 2nd stage; however there is a setting that says "1st stage compressor cycle rate" and this is set to 3.

I am getting the (~85* heat) right out of the plenum about 6" above the top of the furnace/heat exchanger.

I saw "Megatek" in one of the posts for someone else asking similar questions and sent him an e-mail... I imagine that since it is Thanksgiving his GSHP is probably keeping his family and friends nice and toasty today.

I have never seen my new temperature gauge read any higher than 95* for air coming out of the plenum

When the company I bought the heat pump from did the startup procedure they wrote down (on a piece of wood that I have saved) that I could tell the unit was working if the 1st stage produced a 20* delta and the second produced a 30* delta.... I would say the furnace is probably missing that slightly, however if my math is right and this unit is actually putting out its 5T worth of heat that means that I really need an 8.3T unit from Mega-Tek to heat my 2000sq' home? That would be over $30,000 just in drilling the holes. Surely this isn't how it is supposed to be!

It is now back up to a comfortable 63* and "holding steady" in my house now that the sun is coming out. My wife and I are going to go out in all the holiday shopping traffic tomorrow and see if we can find a pellet stove, perhaps that would have been a more economical and functional approach to begin with. Visiting family all moved to my sister-in-laws house this morning at 4:30am.

Anyhow geodeon thanks for your help during this holiday.

Jordan

I did a little searching on Honeywell 8000. I could not find if it is a two stage or three stage. This might be your problem... not the right thermostat.

You need a thermostat capable of 3 stage heat. First and Second stage compressor and then electric back up is stage three. Maybe your heat pump is never engaging the second stage compressor.

Sorry about your family.

It's a 3 stage heat and 2 stage cooling... I have verified functionality of all stages using a volt-meter and the honeywell "diag" test screen that turns on the stages that you ask for. I did have the thermistat set to believe that there were only 2 stages of heat until today. I changed this so that I could run the "emergency heat"

The only time the heat pump engages the 2nd stage is when the difference between the current temperature and the one you are trying to get to is more than 2 or so degrees. I can tell when it kicks in because the fan speed also increases.

I ran the unit on "emergency heat" for a while today and the sun came out so the house is sitting at about 65*. I'll see what the installer has to say and we will have to go from there.

Thanks again,

Jordan

One other possibility how ever slim, maybe the refrigerant charge is low.

Please come back here and let us know what happens, I am curious to know why you are having this problem

Okay here is my theory, (I promise I am normally not as anal as you will see in the rest of this article but I sank a lot of money into this project and I don't want a divorce!)

Today I installed five thermistors and a radio transceiver (I happen to be a firmware engineer for a wireless company) in the Hydro-delta furnace:
*1 on the incoming water pipe
*1 on the outgoing water pipe of the furnace.
*1 on a wall opposite the thermostat
*1 in the plenum on the furnace
*1 outside of the house
*(I would like to install one at the actual register that is delivering air to the room but I ran out of thermistors)

I wrote a little program that wirelessly monitored and stored the turn on/off times of the furnace based on the state of Y1, Y2, and G delivered to the furnace. I kept track of all the temperatures of the 5 thermistors and produced all kinds of tables, graphs, and geek stuff. I also wired the thermostats Y1 and Y2 together so that when Y1 is turned on both stage 1 and 2 of the furnace come on. Y2 does absolutely nothing.

Results were essentially as follows:
* Water comes in at 52.3* and leaves at 49.2 for a delta of 3.1*
* Depending on the temperature outside which ranged from 32* down to 14* so far the furnace would run for between 5 and 7 minutes and then shut off for 15 to 19 minutes.
* There is a ~30* delta between cold air return to the furnace and hot air in the plenum.
* Y2 never comes on (from the thermostat, though it physically does every time Y1 comes on because of above wiring)
* The thermistor on the wall opposite the thermostat stays between 68.8* and 70.5* (WOW, knocks my socks off!)

Conclusion from data so far... Furnace is working as I expect. I did notice that after the furnace shuts off the plenum temperature slowly trickles down from about 100* to 70* so I enabled the thermostat to run another 90 seconds after heat is stopped to milk the last bit of heat out of the exchanger.

I started thinking "I am crazy, what was wrong the other day?" so I changed the wiring back to operating Y1 and Y2 as they are supposed to.
Results were essentially as follows:
* Water comes in at 52.3* and leaves at 50.1 for a delta of 2.2*
* Temperature outside was 17*.
* Y2 never comes on...
* There is a ~20* delta between cold air return to the furnace and hot air in the plenum.
* The Furnace came on for 11 minutes and shut off.... HOWEVER the difference between when it came on and when it turned off on the wall thermistor was -.3* from where it was when it was using both Y1 and Y2 at the same time.
**** This trend repeated

Conclusion here:
I believe that somewhere around 17* is the breaking point for this configuration. The first stage for the previous week was always enough to maintain the 70* temp in the house but as the temperature outside approaches 17* it falls apart. Every time the furnace came on it would ratchet down .3 or so degrees and work its way down. Eventually the temperature works down enough that the furnace runs longer and longer, up to 40 minutes before I intervened. The 2nd stage STILL NEVER WAS TURNED ON BY THE THERMOSTAT!!!

What happens at this magical temperature is that the furnace works it's way into a run all the time and maintain just above that magic 2* point where the 2nd stage is turned on. I imagine that if the temperature outside went low enough the temperature would break that 2* mark and the thermostat would eventually turn on the second stage and return to 70* (only to slowly fail again), but at an outside temp of ~17* it will just run forever.

As a firmware engineer I would say this is a bug in the thermostat, or a bad unit that works 99.999% the way it should?

I imagine that the current fix would be:
A) Leave Y1 and Y2 wired together.

B) Write a piece of code that senses the outside air temperature and when it is less than say 20* force Y2 to turn on when Y1 is turned on by the thermostat.

C) Monitor the run time of the furnace and if it runs longer than whatever the average run time turns out to be then automatically turn on the second stage at that point.

NOTE: I imagine that this Magic 17* point will change this spring when we put in our new windows…

Okay so here are my questions now:
1) Does anyone else have a problem like this?
2) Does anyone know for sure that their thermostat works differently?
3) Does anyone see any holes in my logic here?
4) Is there an efficiency hit for leaving Y1 and Y2 wired together (always running the 2nd stage compressor)?
5) It appears to me that the heat load calculation was based on the furnaces full output at 0*. Should the furnace be able to maintain 70* in the house when outside temp is 0* by only using the 1st stage? If so, then I guess it is NOT a thermostat bug but rather a BTU supply/loss problem.

Thanks to anyone that made it through this post, especially if you can answer any of these questions.

Jordan

Way to go Jordan !!! You nailed this right on the head. Your thermostat is not working properly. Heat pumps have two stages so that if you only need a little heat, then the first stage (which is more efficient) can satisfy the need. If first stage can't do the job, then second stage is supposed to come on and give you the full capacity of your heat pump.

The thermostats that I have seen power up the second stage after running for x minutes, where x is determined by the user. Usually it is the emergency heat that comes on if the room temp is more than 2° below set point.

Your heat pump was not designed to maintain 70° inside while outside was 0° running on first stage only. Which is why your inlaws left at 4:30 am.

Either the thermostat is not configured properly or it is defective. Setting up a thermostat to properly run a two stage heat pump approaches rocket science. The documentation never explains it. I usually end up calling tech support and they tell me about a secret menu that has to be accessed.

If I remember right, you have to tell the thermostat that you have a 3 stage heat pump on the secret menu. Third stage is emergency heat.

Geodean, may I ask what thermostat you have?

I spent 1.5 hours on the phone with honeywell today only to be told that the thermostat is working properly and that at ~17* outside it will run 24/7... I was initially going to just write some code and provide hardware to make this switch both on below 30* but after dealing with honeywell's foreign tech support today and realizing that the time value of money for the conversation would have paid for a NEW thermostat I think I will throw this one away and get a new one...

So: suggestions for a new thermostat that will work with a 3 stage GSHP?

My heatpump is a two stage. I will try and find a good three stage stat and let you know. Any body else out there have one that works?

Hi Jordan: I'm Geogirl and am new to the forum. After watching you struggle with the t-stat issue for the past week, I thought I'd put in my 2 cents. And I ADMIRE your tenacity with going about it with the wireless thermistors & data sensors, etc. Can you back up and specify the "honeywell 8000" t-stat that you are using? (That leaves too much to interpretation given the t-stats that might still be out there). For 3 heat, 2 cool systems you MUST use the "new" Vision Pro t-stat. We use the TH 8320 that has the option for 3-Ht 2- cool WITH aux heat. (Not all models have the correct options in the first place). Once you select the correct system-type in the "not-so-secret" Installer Set-up, you shouldn't have any problem. Sometimes that's where we hit 'done' and don't bother with the CPH. Run-time and ramping up to the next stage is then left to the internal digital controls (assuming that the HydroHeat has it). This t-stat is sophisticated enough to bring on 2nd stage, then 3rd stage AND if allowed to build its algorithms without interference (e.g. trying to control it based on running minutes. etc), it should eventually control the heat pump just fine.

The model was a Honeywell visionPRO 8000 TH8320U1008.

Yup. That's the right one, then. Have you changed the t-stat or how are you controlling the heat pump now?

I am new to this forum and after reading jfuerst initial post it sounds like I could have written it. 3 year old 5 ton closed loop system. 3 year old home well insulated w/ low e windows. Upstairs 1950 square feet. Below grade heated walk-out about 1800 square feet. I believe I have a three-stage thermostat. My problem also is the furnance seems to run all the time. Currently it's 32 degrees outside and the system is running pretty much full-time going between stage 1 & stage 2. What concerns me is the temperature at the register. The closest register to the furnance is showing a stage 1 temp of 81.4 degrees. When it goes to stage 2 the temp 'jumps' to 84.4. Stage 3 (Aux heat) reads 101. Thermostat is set at 68 degrees.What should the temp output be? I seem to recall a technician stating a register reading of 15 to 20 degrees above the thermostat setting is normal. Does that sound correct?

Let's step back a minute. You said it's a 3 year old house with a 3 year old system. Is this long run time situation new or is it chronic, since the system was installed? If it's new, something has changed in the home or the heat pump. Make sure the air filter is clean, all registers open; don't restrict the air flow, etc.  Look also at the loop, water temp, GPM, etc. Check your loop pumps. If one is out that could be why you see low performance. If the problem chronic, then your system probably is undersized. See Geodean's succinct assessment of this problem (10/13/07 in the WF dealer problems thread). You indicated a total heated area of 3750 SF. In northern climates we generally apply 20 BTU / SF for heating - meaning a possible requirement of 75,000 BTUH for your house. I doubt that this is the ouput of your 5-T system. Also, outdoor conditions shouldn't require your aux. heat to kick on yet. Did you bring that on manually or not? Look at the big picture of the system design and size first, before zoning in on the staging and the t-stat.