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jyoderz 01-18-2010 01:11 PM

Heat pump and Honeywell 8000 questions.
Hello and thanks in advance for any comments,

I have a dual fuel system consisting of a 3ton heat pump paired with a 92k BTU 2 stage gas furnace. I am using a Honeywell VisionPRO TH8000 and have a question about it's operation. When it gets colder out (say 30 degrees) the heat pump is able to maintain the temperature in the house just fine but does not have the heating capacity to raise it. What I notice is this thermostat will never engage a second of stage heat when configured for fossil fuel as a backup so the heat pump runs all day and the thermostat is never satisfied. I would like for it to realize the heat pump is not raising the temperature and use the gas long enough to raise to the set point at which time it would switch back to the heat pump. Is there a way to have the thermostat do this?

One other question I have for those who may know, How hot should the heat pump suction line get? I have checked a few friends heat pumps and the line is so hot I couldn't stand to touch it, both of my heat pumps get hot but not burn you hot. Is this to be expected?

Thanks Again

TMcCrea 01-18-2010 05:42 PM

My recently installed geothermal heat pump is paired with my original heating system, a Poliaris propane fired water heater/coil and has a TH8329U thermostat.

When programmed for fossil fuel aux. heat there is no place in the temp range where both systems can operate. I found that if I programmed for electric back-up I could set the compressor lockout point and aux. heat lockout which allows both to run when needed. I just made the change two days ago and the temps have been in the 40's so the 1st stage has been able to do the job.

I think the aux did engage Saturday morning when the adaptive recovery mode raised the night time setting of 65 deg. to my 68 deg. daytime setting. This morning it went into recovery mode at 4:00 and my wife will start swinging if I get up that early to check it tomorrow morning!

Do you have the outside temp sensor installed? If not, you will need one.

beenthere 01-18-2010 06:35 PM

Do you have an outdoor sensor?
Do you have your aux lock out set to a temp lower then 30?

The Honeywell IAQ(YTH9421) is a better stat for what you want it to do.

That line temp varies with heat pump efficiency and indoor air flow.

jyoderz 01-18-2010 08:17 PM

It just seems that if you select fossil fuel you loose the ability to have multistage heat.

I do have an outdoor sensor. I actually did select electric heat and got the same result you did, however, when it got into the teens I found the thermostat running only the fan when a call for heat was made. It had locked out the compressor due to the low temp but had to run for a while blowing cold air until it went to the second stage (aux). I was also nervous about having the gas firing at the same time the heat pump was since the coil sit right on top of the furnace.

Since I cant get a second stage to engage I end up setting the compressor lockout to 40 degrees. A friend of mine with with the same type of HP and house construction is able to keep the lockout set at 25 degrees on a White Rodgers thermostat. That is where I noticed the White Rodgers would turn off the heat pump and fire up the gas (as a stage 2) if the temp was not being satisfied. I guess the Honeywell isn't that intelligent.

If the compressor were to fail, you would still come home to a cold house even though you have a second furnace? Doesn't sound right to me!

beenthere 01-18-2010 09:56 PM

The WR uses different methods of control.
Not all WR will do that.

If you disconnect your sensor. And remove your furnace lock out. It should work the way you want.
But, it will run the furnace any time you set the temp 2 or more degrees higher then room temp.

The IAQ is designed for what you want.

H. Phillips 01-19-2010 07:25 AM

Is the unit not going into defrost? If running all day it should occasionly go into defrost, then the furnace should kick in to prevent your house from cooling in defrost. After a defrost cycle at the same outdoor temp your heat pump should have more capacity till the outdoor coils starts icing up. Other than that, if your furnace costs more to run, then why wouldn't you want your heat pump to run instead of your furnace? Even if it does run all day.

GEAF 01-23-2010 02:48 PM

I have the same thermostat and a Lennox heat pump.

If I understand correctly, you want your gas backup heat to come on if the HP isn't able to get up to indoor temperature in a timely matter?

In the Honeywell installation guide there is instructions to change the "dual fuel heat pump upstage to furnace timer" Setup # 0346. Basically press "system" press and hold the 2 middle buttons, then change function to 0346 and choose minutes.

Set it to 30 or 45,60,75 minutes or Off. If the HP can't get your indoor temperature up to your set degree by 30-75 minutes, then the HP will shut off and your gas furnace will come up to get it up to temperature. Once up to temperature, the HP will take over.

jeffsinc 04-03-2010 07:51 PM

Dual fuel Coleman heatpump
I have had this system for almost two years and it has been great...Except for the fact that the guy that installed it had never done one before and everytime the seasons change I have had to call him back to switch a jumper in the thermostats all four so that they will switch to heat or like now back to ac. Please if someone knows why let me know I am almost positive he has just installed it wrong and need to know....:furious:

beenthere 04-03-2010 07:53 PM

Post brand and model number of your zone panel.
Or do you have 4 heat pumps.

jeffsinc 04-03-2010 08:49 PM

Ultra Zone
Not sure of model number had a lot of numbers and none were labeled as model but here are some I found UZC4 RTF D-1 94v-0 and then on a sticker at the bottom of the panel it had 4002707E0108050072 so I hope one of these numbers are the one.:thumbup:

beenthere 04-04-2010 07:29 AM

Thats an EWC panel. Its one of their higher end panels.
Your tech doesn't have something set up right/and or wired right.
You don't even need heat pump compatible thermostats when you use that panel.
That panel can do auto change over. Meaning that after one stat is done calling for heat. Another stat could call for cooling, and it will go into cooling mode without you having to do anything(if that option is enabled).

Did he leave the install instructions with you?

Post how one of the thermostats are wired.

Houston204 04-04-2010 09:42 AM

It seems like the toggles are set incorrectly...

jeffsinc 04-04-2010 10:45 AM

Thermostat wiring
the white wire is on W2 there is a jumper on RH to RC and Red wire on RC Brown wire on C and Blue wire on O/B and the yellow is on Y and Green wire on G Hope that tells you something

jeffsinc 04-04-2010 01:58 PM

Low Pressure Switch Lockout
Hey so I went and took the cover off the unit out side and the led diagnostics are saying that there is a low pressure switch lockout how can I reset or fix this.

beenthere 04-06-2010 02:26 PM

The stat wiring sounds correct. No reason to switch any wires for it to be used for cooling, and then again for heating.
So the problem may be in how he has the dip switches set up on the panel.

Unless the wires aren't connected to the same terminals at the panel.

To reset the pow pressure lock out. Turn off the air handlers power for half a minute. That will reset the lock out. If the pressure is back up to where it belongs.
It may have tripped because of a leak, or a bad device in the system, or a dirty air filter. So if it trips again. You'll need a service tech to check it out.

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