Hi,

 Northern Minnesota (Grand Rapids), new CM T27, 5 ton, well loops filled this
winter with food grade glycol (not my 1st choice), just applied power this past
weekend. JW3-FP1 jumper is cut. This has been 'do it yourself' as much as I can.
The entire loop is 8 feet below grade, the basement was at freezing temp,
so the part of the loop entering the house was pretty cold.

 Power on, all leds green, fan slow, 4-5 minutes later the fan speeds up twice, 7
minutes from power on the compressor and flow controller turn on, the heating coil
is warm, after 3 minutes, then lockout.  FP1 Fault code 4.

 Found Technical Bulletin TBJ005 (2007) about bad thermistors.

Since the Technical Bulletin is from 2007, I would think I should be covered.
Should I just replace the thermistor or do the test on it (mentioned in theTSB).
Should I look elsewhere?
 I won't get a chance to work on it for a couple weeks, so would like to get my ducks in a row.

 I havn't taken any measurements as far as flow or temperature.

 The system was filled and purged by supposedly experienced folks (they sell Waterfurnace).
 Can anyone recommend a good place (on the web) to purchase p/t gauges?

 Searching the website I found mention of the bad thermistor and new design, not sure what I have.

 Thanks alot.

had bad thermistors, bad switches etc. neeed way more info.
pressure gauges are as easy as a basket ball inflation needle and a gauge.

Can anyone recommend a good place (on the web) to purchase p/t gauges?

Geothermal Supply Company

Posted By geodean on 12 Mar 2012 09:11 AM

Can anyone recommend a good place (on the web) to purchase p/t gauges?

www.flowcenterproducts.com/accessories.php

Gauges on the way - may be fixed or will have more info on Monday.

Fixed - there was air in the loop. When they initially filled the loop and purged the air, there was no power to the flow controller (Geo-Pulse - no pressure type, so pressure gauge is useless).
This past Friday, the HVAC guy wired the flow controller direct to 220v and it started pushing water and air in a few minutes, displaced about 1 gallon of water/glycol.
He mentioned that the 5 wells are not in series, but rather in parallel, there is a manifold for in/out under the ground.
How is all the water in each well used then?
How can I be sure each well is used equally, purged of air and that I am getting all the btu's out of the wells I should be?
BTW - 38.3 degrees EWT and 33.3 degrees LWT - matches spec of the furnace.

Glad it is working for you. I'm a little suprised installer did not properly flush system- that is the only way to know all the air is out.

Posted By steve_mn on 19 Mar 2012 12:34 PM
He mentioned that the 5 wells are not in series, but rather in parallel, there is a manifold for in/out under the ground.
How is all the water in each well used then?
How can I be sure each well is used equally, purged of air and that I am getting all the btu's out of the wells I should be?

The manifold sends equal amounts of fluid to each well provided the air has been purged from all wells. Usually the installer uses a high flow purge cart to push all the air out.

EWT of 38*F after only a few days of use, may mean not all wells are purged, maybe not, I am not a pro, just a homeowner w/GSHP, and don't know what kind of load has been put on the HP (cold weather out there?)

ChrisJ RI

Not cold at all, was 60-70 degrees. Northern MN, cold water (normal) - measured temp soon after it began running.
Have left it to run, added 1 gallon of distilled water, will check in a couple weeks when we are back to the house.
Will check temps again as well as get specific gravity to determine % of poly-glycol.
Will also get supply and return air temps.
Anything else I should check?
Thanks

If the water in the flow center canister drops more than 1 inch when the circulation pumps start up, then there is still air in the loop.