Advice for WaterFurnace problems

[lawsdt71]

We built a new home and installed a WaterFurnace geothermal system in November 2011. The system is set up with 4 zones, 3 on the main floor and one for the basement. We live on a lake in NC and the coils are 13' deep in the lake. From the time it was installed, it worked perfectly. We were able to adjust all thermostats to control individual temperatures, and keep the settings lower in the winter and warmer in the summer. Bills were low and the house (which has complete envelope foam insulation) was quite comfortable. We also installed hot water from this system to the HW heater.

Then last fall we got a "Call for Service" notification on all of the thermostats. Our technician (very motivated and helpful) came out and found a problem where the pipe leading to the HW heater had steam coming from it. He shut that down. After consulting with WaterFurnace, and doing some additional testing, they determined that the problem was the main board, the thermistor, and the shutoff valve. After a while they replaced these.

But while waiting for this repair, and even after replacement, we keep getting "Call for Service". So we did some testing. First we tested all thermostats to see if leaving one off would keep the system from needing service. It turned out that the one on the west side of the house was the culprit. As long as we left this off, we never got a "Call for Service." So we swapped two of the thermostats and the west zone still had the problem, meaning that it wasn't the thermostat, it was the zone. In the meantime, our home is no longer comfortable, and the bills have increased by 50% over what they had been last year. Since recent weather has been more temperate, I can't attribute this to temperature.

Today, our technician brought an expert from WaterFurnace with him. This person has 15 years of experience with Geothermal systems. At the end of the discussion, they told my wife that (1) the problem is that when a single zone is running, there is too little airflow though the constricted ducts, and the system overheats, and (2) the reason that the bills have gone up is that when the system overheats, it uses the emergency electric heat. So, as a temporary measure until they have a better idea what to do, they have increased the airflow from 25% to 70% in the west zone (or may be in all zones - I wasn't there and my wife didn't tell me).

So my question is this. If a WaterFurnace system is set up to be zoned in four zones, why is ours having this problem? And does their explanation of what is happening with the system overheating and the emergency electric heat kicking in make sense?

Lastly, do you have any recommendations for us to try?

Thanks,
David

[SkyHeating]

First of all, that is not a WaterFurnace problem that is an installation problem. It sounds like you have issues with your ducting, because if your ducting is to small or to large for a zone it will cause issues. It also sounds like your intellizone panel may not have been setup properly which is also an installation issue and not a WaterFurnace issue.
Their explanation of emergency heat kicking in could be if the system is not able to heat the zone then it could kick on and it could not heat the zone if the ducting is to small or if the Intellizone setup was not properly done.
It sounds like you need to have a chat with your installer and how they sized your ductwork because you even mentioned "constricted ducts" which is not a WaterFurnace issue.

For more help please reply back with your model number(should start with NSV/SDV/NVV/NDV) of equipment and what thermostats you have.

[lawsdt71]

This is a model NDV072A141CTR. The thermostats are WaterFurnace part no 37-7194C.

Yesterday, they came back. They installed an overpressure bypass from the main heating duct to the main return. This morning the "Call for Service" is on again. Whenever it comes on, I have to cut the power to the system and wait for 30 seconds or so, then turn it back on to reset it. So it is now reset, the west zone is again turned off and I am calling the technician again.

As far as the emergency electric heat coming on, this is not because the temperature in the house is low. In fact when "Call for Service" comes on, the temperature in the west zone stays right where we set it at, and the other 3 zones heat up to 2 - 5 degrees above the temperature on the thermostat.

This has to be a problem with a controller somewhere, I believe. The system worked fine for a year. Now it is going haywire.

[WF_Inc]

lawsdt71,

We have read your comments and would be happy to look into your inquiry further. Can you please provide the serial number of your WaterFurnace unit, as well as the name of the contractor you are working with? If you do not wish to post this information publicly, please feel free to send us a private message.

WaterFurnace International, Inc.

[1-Hvacdoc]

I agree with Sky 100%. Would be nice to see some pictures of your system. How many registers are on each zone? Do you have four zoning dampers or does each run have one? Has any one said what code the board is flashing when it goes out? Adding the by-pass may have made the problem worse by dumping too much hot air back across the coil.

The fact that it may have worked fine the first year really means nothing as the improper zoning design may be contributing to parts in the geo weakening or going bad. When the unit senses a problem it will shut off the compressor section of the geo and turn on the heating elements.

You didn't mention witch zoning panel you have.

[lawsdt71]

WaterFurnace,
Thanks for offering to help. The person from WF who came out is named Wes and I believe that he is from Statesville, NC. Our contractor is Energy Efficient, 704-868-8223. Their response and eagerness to solve this problem has been outstanding. The S/N is 110500035, Job #123915. At this point, Energy Efficient may believe, as I do, that the problem is in the controller board, not in the ducting.

This is a link to pictures of the unit, zoning panel and ducting
https://plus.google.com/photos/10997...Iu1vreIsrCakQE

[lawsdt71]

Thanks to both Hvacdoc and Sky for the advice. WaterFurnace has also replied, and replied to their message with answers to some of your questions, and a link to pictures of the unit, ducting and zone controller.

[Oldsolarguy]

Was reading the post here. My experience with installing waterfurnace equipment is that the air bypass is not needed because of the ECM blower motor. I think it might be a zone controller problem or a setting issue. What kind of dampers did they Install? Could be duct sizing, but doubt it considering the unit worked fine for a while.

[SkyHeating]

They installed a bypass? I have never had to do that with the intellizone panel like old solar guy pointed out. Something else is wrong here.
The NDV072 is a large unit, was this a retrofit or new install? If its a retrofit did they enlarge any of the ductwork because that is a 6 ton system and if you had a gas furnace and AC or HP before it had at most a 5 ton blower motor.

[Oldsolarguy]

I just wonder if its a performance problem. If your bills went up, sounds like your strip heat is running more then the compressor. Also would explain you not being comfortable but the space warm( compressor not keeping up, then you get strip heat untill zone is happy, then starts all over again.) what kind of codes are you getting on the front of the unit. Have seen the evap coils develop leaks once in a blue moon, not enough to shutdown due to low pressure, but enough to cause performance issues. Many factors can be in play here. The unit needs a full check over sounds like.( subcool,superheat, heat of extraction, freon pressures.) I would've thought the tech should have done that. Worst case, they a tech support line for things like this.

[WF_Inc]

lawsdt71,

Thank you for the additional information. We have been in contact with your contractor and have requested that they contact us while in front of the unit. It was our understanding that they were going to visit this week. Have they been to your home at this point?

WaterFurnace International, Inc.

[Oldsolarguy]

Just curious if your issue has been corrected yet? or at least a solution.