How to make this work-Lennox Dual Fuel G61MPV-60C-091 & XPG15-042 - ComfortSense 5000

[-Jim-]

Ken,

First of all I checked my Thermostat settings as requested. The Installation Manual (Thanks again ) gives me all the codes when in Installer Setup mode. The owners Guide I was given shows only some selected codes and omits anything with real impact.

The System Type is 12 (3 Heat & 2 Cool Heat Pump with auxiliary heat), and the number of Cycles per hour is 3 (Recomended setting for Compressors. Factory Setting). I think you posted these were your settings. By the way who was your contractor?

Converting Region IV to V may (should?) impact the HSPF of 8.7 as my limited understanding of this number is it is derived by simulated testing of the System using the parameters (Heating and cooling days, ambients, etc.). Otherwise the specification would not bother to have a Region component. Perhaps one of the Gurus here could chime in and set us straight??

Is the Outside Design Temperature for Metro Vancouver, your 17° F, -8° C righteous data? I too find it on some web sites but can't find it on any Enviroment Canada Site. (Here's the definition I found: In heating calculations, the outside design temperature is defined as the coldest outside temperature expected for a normal heating season. )

I don't think the COP for the X15 will match the XPG-15. I posted earlier after finding some XP-15 Data here:

http://www.cooperheatingandcooling.c...ing%20Data.pdf

I posted

"beenthere,

I checked the sheet and there is nothing close. My system is:

AHRI Certified Reference Number: 3339030
Date: 12/11/2009

Product: Split System: Heat Pump with Remote Outdoor Unit-Air-Source
Outdoor Unit Model Number: XPG15-042-230*
Indoor Unit Model Number: CX34-43C+TDR+G61MPV-60C-091*
Manufacturer: LENNOX INDUSTRIES, INC.
Trade/Brand name: XPG15 DEDICATED DUAL FUEL HEAT PUMP
Manufacturer responsible for the rating of this system combination is LENNOX INDUSTRIES, INC.
Rated as follows in accordance with AHRI Standard 210/240-2006 for Unitary Air-Conditioning and Air-Source
Heat Pump Equipment and subject to verification of rating accuracy by AHRI-sponsored, independent, third
party testing:

Cooling Capacity (Btuh): 40000
EER Rating (Cooling): 12.00
SEER Rating (Cooling): 14.50
Heating Capacity(Btuh) @ 47 F: 35600
Region IV HSPF Rating (Heating): 8.70

Heating Capacity(Btuh) @ 17 F: 22200

I'll email Lennox."


I could not find any similar XP-15 Unit that has similar output to my XPG-15. You advised: "The graph of the COP on that sheet doesn't match the XP15, but if you unprotect the worksheet you can change the formulas used to compute the COP numbers in the table to match."

I tried to unprotect the sheet but it asks for a password. Care to advise? Thx.

Did you do an energy Audit? What losses did it predict? What is your Heatpump / Furnace System?

Thanks for the inputs and posts.

[beenthere]

Vancouver AP 19°F.

[thekenward]

Jim,

This is great -- two homeowners who don't know any better chatting it up on a pro HVAC site! Frankly, it's great to meet somehow who is virtually the exact same boat as I am!

The System Type is 12 (3 Heat & 2 Cool Heat Pump with auxiliary heat), and the number of Cycles per hour is 3 (Recomended setting for Compressors. Factory Setting). I think you posted these were your settings. By the way who was your contractor?

Yes, those are my settings also, though I was also interested in your settings for numbers 240 through 270 (I have the cph for conventional heating set to 5, where I believe it should be set to 3). My contractor, BTW, is exactly the same as yours.

Is the Outside Design Temperature for Metro Vancouver, your 17° F, -8° C righteous data? I too find it on some web sites but can't find it on any Enviroment Canada Site.

Check http://www.quickscribe.bc.ca/images2/bcappc.pdf for data around BC. I think this is legitimate.

I don't think the COP for the X15 will match the XPG-15.

For my purposes, I'm thinking it's going to be close enough to provide some approximate data. There's probably inaccuracy, but I'm doubtful the differences are more than a few percentage points. (I could be wrong though!) I have a 2.5 ton unit.

I tried to unprotect the sheet but it asks for a password. Care to advise?

Huh, weird. I used OpenOffice, and there was no request for a pw,

Did you do an energy Audit? What losses did it predict? What is your Heatpump / Furnace System?

I'll answer your personal questions, even though you might be a heat pump stalker....
Yes; 33000 Btu/hour (after retrofit, estimating ~40k before) for heating, 17.8k Btu/hour cooling load; G61MPV-36B-071 + XPG15-030-230 + CX34-38.

[-Jim-]

Jim,

... though I was also interested in your settings for numbers 240 through 270 (I have the cph for conventional heating set to 5, where I believe it should be set to 3).

The only setting in this group is 260 which is set to 5 => the same as yours. I too found it odd it wasn't set to 3...

My contractor, BTW, is exactly the same as yours. So you get to ask about the 260 Setting?


Check http://www.quickscribe.bc.ca/images2/bcappc.pdf for data around BC. I think this is legitimate.

I saw this before but was hopeful I could get substantiated data that was not from 1995. I know climate change is slow...but 15 years later may have more accurate data due to better instrumentation => but this is better than no data...

For my purposes, I'm thinking it's going to be close enough to provide some approximate data. There's probably inaccuracy, but I'm doubtful the differences are more than a few percentage points. (I could be wrong though!) I have a 2.5 ton unit.

I'm still hopeful the real XPG-15 Data will pop up somewhere.

Huh, weird. I used OpenOffice, and there was no request for a pw,

I sent it to a Buddy who sometimes can unlock spreadsheets...


I'll answer your personal questions, even though you might be a heat pump stalker....

Yup, that's me alright

Yes; 33000 Btu/hour (after retrofit, estimating ~40k before) for heating, 17.8k Btu/hour cooling load; G61MPV-36B-071 + XPG15-030-230 + CX34-38.

Did you have any discussion prior to purchase on the significance of the indoor unit (Heat Exchanger)? Did they give you any options or ? Were you enticed by Costco as well?

[adamp]

hello

I have lennox G71MPP with lennox 5000 thermastat
LED is displaying H1A622 what does this mean.

Dip switches 1 off
2 off
3 off
All appear to be default

question is is furnace set up correctly?

Adam

[thekenward]

Open question: Is "3 heat/2 cool" the correct system type for a 1-stage heat pump and 2-stage furnace, using a Lennox Comfortsense 5000?

[adamp]

G71MPP is not heat pump, it is high efficiency Variable Capacity Gas Furnace.
Two-Stage Gas Valve
Variable Speed Blower Motor

All Dip switch are set Down (off I think)

Capital "H"
LED is displaying H1A622 what does this mean?


Thermastat only using 5 wires
W, W2 , R, G, Y

ADam

[-Jim-]

adamp,

I don't know why you want to Hijack this Thread.

You should start a new one, or search against your issue before posting at all.

Check out this Thread. It may be helpful:

http://hvac-talk.com/vbb/showthread.php?t=401622

[-Jim-]

Open question: Is "3 heat/2 cool" the correct system type for a 1-stage heat pump and 2-stage furnace, using a Lennox Comfortsense 5000?

Agreed, and also the Cycles per Hour setting...

[-Jim-]

Well, I bit the bullet and called the Contractor.

The last straw was at about 8:30 this morning when I glanced at the Stat's outside temperature and it was 36 °F. Then less than an hour later I glance at it and it's 49 °F. Now I know outside temps will swing, but on an overcast day here in Lotusland it doesn't move like that.

According to the Weather forecast it's supposed to swing between a high of 46 °F and a low of 34 °F in the next 24 Hours => not in one hour.

The Contractor is very responsive as they said they will be here between 2 & 4 pm today. (Can't beat that!) I decided to ensure I got someone on top of their game with respect to the Tech and asked a few questions. The poor receptionist / service scheduler was quite lost on coefficient of performance (she never heard of it before) so I had to explain it to her. (The Blind leading the Blind...)

So I've made a note to ask about:

1- System Type (0170 - Set to 12 - 3 Heat / 2 Cool Heat Pump with Aux Heat) just so I understand why.

2- Cycles per Hour (0260 - Set to Standard Efficiency fossil fuel Furnaces when I've got a High Eff. G61.) I really don't know what the imapct of this setting will do. But...

3- Heat Pump Compressor Lock out (0350 - set to 35 °F). How did they arrive at this number? Science Please...

4- Adaptive Intelligent Recovery (0530)- This is disabled - Why? I would think we be using the "brains" of the Stat to learn the enviroment and adapt. My Old dinosaur Stat did that.

5- Heating Mode Extended Fan On (0650) - just want clarification as to benefits / issues.


While I was writing this I got an email back from Lennox! It says:

Jim,

I have requested an extended ratings document from engineering on this product. As soon as I get this document I will forward it to you.

It should answer most of your questions.

Thanks,

Bill


So things may be coming together soon. I will advise.

[thekenward]

Jim,

That is fantastic. Please let us know what transpires. If the tech makes any changes, I may want to contact them as well.

[-Jim-]

Jim,

That is fantastic. Please let us know what transpires. If the tech makes any changes, I may want to contact them as well.

Well the Tech just left. He changed out the Probe but advised that the new one probably won't be much better. (The connections were twist on marrettes). The old probe was inside the Heat Pump Case, but extended down through a small hole but was touching the concrete covered styrofoam pad they used to mount the unit; and it was a bit wet / muddy. He didn't like that location and moved it to a "dry" location near the Starting Capacitor for the compressor motor.

He said he wasn't 100% sure but that probe has nothing to do with the operation of the Thermostat / Heat Pump / Furnace. He said there is an entirely separate (and different looking) thermocouple probe that is connected directly to the heat pump sharing a common pair of wires with a probe on the compressor that controls defrost; all of which later connects to the Furnace (I was not shown this probe nor this wiring).

I advised I was skeptical that Lennox would bother pulling separate wires all the way from the second floor of my house, down to the basement, through the funace area, and outside terminating inside the Heat Pump => just to give me (The Homeowner) and inaccurate indication of temperature. He said he was going to follow up with the Lennox Tech and make sure he was right as I got him to thinking...

He also advised:

1- System Type (0170 - Set to 12 - 3 Heat / 2 Cool Heat Pump with Aux Heat) just so I understand why.

He advised this could be set to 7 - 2 Heat / 1 Cool Heat Pump with Aux Heat and did so => so I assume this originally was in error?? He was at a loss for word as to why the change...He set it to 7.

2- Cycles per Hour (0260 - Set to Standard Efficiency fossil fuel Furnaces when I've got a High Eff. G61.) I really don't know what the imapct of this setting will do. But...

He didn't know either, but other changes made in the settings caused this step to be skipped in the sequence, showing it was no longer applicable.

3- Heat Pump Compressor Lock out (0350 - set to 35 °F). How did they arrive at this number? Science Please...

He had none. It seems it's this Contractor's standard. They don't bother with Energy Audit Reports or Heat Loss numbers. He advised in Ontario with electric back up he's set it all the way down to max out heat pump output.

4- Adaptive Intelligent Recovery (0530)- This is disabled - Why? I would think we be using the "brains" of the Stat to learn the enviroment and adapt. My Old dinosaur Stat did that.

He advised I could change this if I wanted the Thermostat to anticipate the setback settings. It's now enabled so it should be warm when my wife gets up at 6 AM to get ready for work.

5- Heating Mode Extended Fan On (0650) - just want clarification as to benefits / issues.

He advised this is just to squeeze the last bit of heat out of the heat exchanger prior to shutting off the fan. I left it off pending comments from you folks!!

Somehow when he was poking at the Stat he advised the backup heat was set to Electric (it wasn't yesterday - or this morning...) and that would cause the unit to act in weird ways. (I think he may have inadvertantly poked the wrong button when looking around --maybe...)

So anyway, we'll see how it goes. I really think the Temperature Probe question is still outstanding. Maybe a Guru or Mod here will chime in with an opinion or two.

I await your interesting replies!

[thekenward]

Hm!

1. Interesting that he changed the system type. Everything still working well, or have things changed?

2. There are several codes for setting Cycles per Hour. I'm guessing that one of the others is now set to 5 instead.

3. If you read the XPG15 manual (that the installer hopefully left for you), it seems to me to indicate that the heat pump won't operate below 32 F anyways (pg. 37, #3) . I could just be interpreting this wrong.

I've also since been reading that the Comfortsense 5000, when used for these units, doesn't control when the furnace goes into high fire -- that decision is made by the furnace, if the heat demand isn't satisfied after 10 minutes (the delay is set on the furnace's electronics). I've read opinions that it's more desirable to let the stat do that instead of having it timed, but that requires an upgrade to the Comfortsense 7000. The 5000 essentially acts like a 1-stage stat with our 2-stage furnaces. I'm still looking into that one.

Edited to add:

I've been talking to another tech on a different forum. (I don't think naming the forum would be in line with hvac-talk.com's rules.) He informs me that the XPG15 has a built-in temperature change over switch which shuts it down at around 32 F, and that the outdoor temp. sensor should be used for display only. He echoed that the settings for the stat as described in the documentation are correct.

[-Jim-]

Hm!

1. Interesting that he changed the system type. Everything still working well, or have things changed?

It's gotten Milder so the Heat Pump is the only thing working now. It seems to be fine.

2. There are several codes for setting Cycles per Hour. I'm guessing that one of the others is now set to 5 instead.

3. If you read the XPG15 manual (that the installer hopefully left for you), it seems to me to indicate that the heat pump won't operate below 32 F anyways (pg. 37, #3) . I could just be interpreting this wrong.

On Page 37 in my Installation Manual (I have no User Manual) it's about Defrost Sensors not operating temperatures.

I've also since been reading that the Comfortsense 5000, when used for these units, doesn't control when the furnace goes into high fire -- that decision is made by the furnace, if the heat demand isn't satisfied after 10 minutes (the delay is set on the furnace's electronics). I've read opinions that it's more desirable to let the stat do that instead of having it timed, but that requires an upgrade to the Comfortsense 7000. The 5000 essentially acts like a 1-stage stat with our 2-stage furnaces. I'm still looking into that one.

Edited to add:

I've been talking to another tech on a different forum. (I don't think naming the forum would be in line with hvac-talk.com's rules.) He informs me that the XPG15 has a built-in temperature change over switch which shuts it down at around 32 F, and that the outdoor temp. sensor should be used for display only. He echoed that the settings for the stat as described in the documentation are correct.

That doesn't follow the set up on my Brother in Law's 2.5 Ton XPG15 with Electric Aux Heat. It runs down to 23 F (and I've seen it running below freezing). It also doesn't follow Lennox's liturature, brochure's, etc.

I'm still waitng on the promised Data for the XPG15 from Lennox - 20 days later after they said they'd get it to me...

[thekenward]

Take a look at Lennox's own doc. for the XPG15: http://tech.lennoxintl.com/PDFs/506212c.pdf to see that the heat pump controls the switchover temperature (pg. 1). If you look through the guide, you can see what the stat's settings should be (pg. 24). Apparently the XPG15 is quite different from Lennox's heat pumps that are not dedicated dual-fuel units. The concern I'd have is that the stat's setting of balance point would conflict with the XPG15's control of switchover.

The contractor is coming out tomorrow to upgrade me to the ComfortSense 7000, and I'll be hanging around to make sure they set it up according to the manual. I'll let you know how it goes!

[pacnw]

usually the heat pump is allowed to run at the same time as electric back up heat strips.

it should NOT run at the same time as fossil fuel back up.

[thekenward]

That doesn't follow the set up on my Brother in Law's 2.5 Ton XPG15 with Electric Aux Heat.

Are you sure he has the XPG15? That is supposed to be a dual-fuel unit, not a heat pump with electric backup.

[-Jim-]

Are you sure he has the XPG15? That is supposed to be a dual-fuel unit, not a heat pump with electric backup.

Ken,

You are correct, I called him for clarification to be sure (he's not too technical) it's an XP15-030-230 CBX32MV024/030-230-6. I guess he got confused with the XPG.

I did get the data from the Gent @ Lennox (almost 2 megs in two spreadsheets.) last night. I'm still digesting the data, but my unit is below and I'm surprised at the output below the 0°C / 32 °F. I did the COP based on the data (orange column) and see it still amplifies energy far below where I was lead to believe it would. (-29°C )

Of course I could be all wet and if so (hopefully) a Pro here will correct me and get me back on the right track.

The last Tech that was here said, if it was his unit, he'd crank the Heat Pump setpoint all the way down as if it can't keep up after the 2nd call for heat then the Gas Furnace would kick in. I'm still mulling that over.

Why did you move to the ComfortSense 7000? How did it go? Did you learn anything new from your installer?

[thekenward]

Jim,

Here's *my* understanding, as a homeowner and non-HVAC pro, of where we're at. Take it for what it's worth!

The XPG15 is a dedicated dual-fuel heat pump. It's designed to work with the CS 5000 and 7000 thermostats. Unlike conventional HPs, it has a unique control system with an onboard temperature sensor. In a conventional dual-fuel setup, the thermostat uses its balance point settings in concert with an outdoor temperature sensor to determine if the HP or the gas furnace should be used for heat. With the XPG15, the stat should be setup with no balance point. The XPG15's control board will signal the gas furnace for aux heat when its outdoor temp sensor detects an OD temp below 32 F, and will use the compressor when it is above 32 F (unless it's on a compressor timeout or defrost).

With the CS 5000 and G61V, when gas heat is called, the furnace's 1st stage (low-fire) fires. If the temp setpoint isn't reached within 10 or 15 minutes (set with DIP switches on the furnace control board), the G61V's board fires the 2nd stage (high-fire), until the setpoint is reached.

With the CS 7000 and G61V, when gas heat is required, the stat checks the temperature differential between the current indoor temperature and the setpoint. If the differential is 2.5 F or more (settable on the stat), the furnace goes to high-fire immediately. If the differential is less than 2.5 F (again settable), it will go to low-fire. On a cold day, when the HP is locked out, the furnace should be able to run for longer time periods (i.e. longer than 10/15 minutes) on low-fire to satisfy heating. My understanding is that this is both more efficient and more comfortable than having the furnace going on high-fire for a short burst to make up any heat difference, if there is any remaining after the time delay has elapsed.

The install today was good. The tech was on the phone with the service manager to confirm settings, and I was able to ask questions of the tech with the manager on the phone still. I watched and was able to confirm things were set up per the installation manual. Now, it's just a matter of seeing how things work out.

(I may have to call them out for an adjustment to the blower speed. When the HP is on, I can hear a slight whining sound through the ductwork, over the roaring sound of the air. We'll see how that goes.)

How's that?

[-Jim-]

Ken,

Your explanation on operation sounds quite reasonable. I hope the move to the C7000 wasn't too costly if all it does is change the Furnace operation / responsivness when looking for Heat. (Makes it faster when faced with real demand, but run on the lower setting longer.)

I had a whining sound from a cold air return close to the furnace and the Contractor was next to useless when I brought it up - twice. I couldn't find a high velociy vent so I ended up adjusting the vanes with Glass pliers, and eventually puttting a foam gasket around it to change the resonant frequency. It was particularly annoying when the Furnace was on High Speed.

I somehow find it strange with the Heat Pump locking itself out below 0 °C / 32 °F, and also not allowing the Heat Pump to assist in heating below this point . If the data sent to me is accurate, and I've calculated the COP numbers correctly, the Heat Pump could economically contribute to the Heat well below this point. I wonder what the logic here is? They let Electric Aux Heat to work in concert with the Heat Pump, so why not a Gas Furnace?

That math works out to the Heat Pump being cheaper to run all the way to -21 °C /- 5.8 °F then the Gas Furnace becomes cheaper. Of course by then the Heat Pump would only contribute ~20% of the Heat required (13,400 / ~70,000 BTU / Hr.) to keep my House warm. This is far below the extreme minimum of -16° C (3.2 °F recorded on 12/29/1990).

If I was to have Electric Supplemental Heat it would be making up the shortfall below the Balance Point (for the sake of argument I'll use 2 °C / 35.6 °F for this point as per my Balance Point Graph posted earlier) but it lacks the amplification factor of the Heat Pump, and therefore the full incremental cost per Gj ($24.46) applies.

(If the data given by Lennox and the Energy Audit are correct, the Heat pump (alone) shouldn't be able to maintain the house at temperatures below about 2 °C / 35.6 °F.)

I think I found a mistake on the Lennox supplied Data. Under Compressor Motor kW Input they've got the data in Watts not kW. (A Motor with 2895 input kilowatts would be over 3500 HP. 1 HP is 746 Watts.) I adjusted it and then calculated the cost per hour for two scenarios.

Attached shows the cost to run my system as installed with the Heat Pump cutting out below 2 °C / 35.6 °F and the Heat supplied from the G61. Then I did "what if" it had electric back-up instead.

With the Heat Pump cut out mode we have it seems the Gas Aux Heat is still quite a bit cheaper than an Electric suppliment mode. For my home Gas cost is 78% of an Electric mode @ 2 °C / 35.6 °F, sliding down to ~ 50% near the absolute minimum temperature ever recorded.

There are still a few Questions unanswered but we are making progress.

(Like why would they lock out my Brother in Laws Heat Pump at -5 °C / 23 °F and go totally to Electric Heat when the Heat Pump is still capable of adding Heat?)

I wonder why no Pros have jumped in to help us here very much?