FP1 Faults & Lockouts

If pic #4 is in the correct orientation then the installation is a no-no from Grundfos.

Mark

 

Hello,

I have a similar problem of lockout or trip.
Can someone guide me?

I have 2 heat pumps , one 5 ton capacity and second one 3 ton capacity.
3 ton is second stage capacity.
Units are from ''comfort aire by heat controlled inc''
It is a closed loop sysytem with water only circulated in pipes.
My first and second floor is 6400 square feet.
basement is 3200 square feet.
Basement is open to first floor and second floor due to staircase.
Approximate cubic feet of air to heat ( including basement area) is 100000.
There are 4 wells and each drilled vertically down to 350 feet,
I live in orange county of new york.

units are operational for 5 months.

Air conditioning worked well in july and august.


I have radiant floors for basement , first floor and second floor.
In the month of October radiant heat was working good in first and basement floor.
When I turned on second floor, 5 ton unit started locking out.
I was advised to switch of radiant heat and use air conditioned blowers to heat the house.
It was working reasonably well.
Now , again 5 ton unit is tripping or locking out.
3 ton unit keeps working.
Of course 5 ton unit requires more flow because it is larger.
Can someone advise what I should do?

Thank you

Kumar

 

Hi Mark,

Pic #4 is the correct orientation. Interestingly enough that is the pump that I mentioned, early in this thread that, that was VERY hot to the touch so I replaced it with a new pump. The pump in the pic isn't even 1 week old.

So, how should the pump be installed differently? Would its present orientation negatively effect my GPM? Is pic of the other Grundfos pump with the flow meter installed correctly?

Also, since it looks like I'm going to be doing at least a little re-vamp in the piping in the house, would it be more efficient to bring the pipes 2 feet further inside the back wall of the garage and in front of the heat pump to eliminate the mess that takes the pipes around the HP twice? Seems to me if both pipes were lower and more directly routed to and from the HP it can only help the situation. Any thoughts?

Thanks.

 

The more fittings you can eliminate the better

 

Please start a new thread

 

You said it was plumbed in 1". I expected we were talking 1" ID. Your fittings on 1" Pex are about 3/4" OD.
Your asking a lot of that pipe.
Was this pipe recommended by the guy that said the pond only had enough btu's for open loop but not closed?

 

bfuller:

Try this link: http://www.us.grundfos.com/Web/Download.nsf/Pages/EDCE0139826E87B088256A6F0071D7A3/$File/L-UP-TL-018.pdf

or read the instruction manual that shipped with the pump.

I do not know for sure if being upside down will bother the flow but it is not good for the pump. Wet rotor plumps are lubricated by the fluid they are pumping. They way that pump is positioned it will not spin freely as designed.

Joe brings up a good point on the near heat pump piping and fitting size. So with all those fittings your 1" pipe turns into 3/4", and allows only 3.9 gpm.

It is all about flow.

Mark

 

The installer seem to lack the fundamental understanding what it takes to feed your heatpump with the flow of water it needs. You need to redesign the source piping and pumping completely. You installer simply did not understand flow and pressure drop. This combined with an open system getting water from the bottom of a "dirty" pond is a setup ensuring guaranteed failure of your geo system. You cannot band aid it, it will never work well, if at all.

 

Doc,

I completely agree. I've still got the temporary setup with the submersible pump on the end of the intake line submersed in a shallow location in the pond. Even with 2 feet of intake pipe right at the surface of the pond I'm still getting approximately 6 GPM and the house it nice and warm. This week I've made arrangements with a guy we know who is well-versed in plumbing and water pumps and we are going to re-fit the 1" PEX line inside the house with pipe that he says will work much better for the existing situation, not to mention route the piping more efficiently to and from the HP.

I think what the installer failed to recognize is that each install should be seen as its own unique scenario. For this scenario it seems to me that there is the testing that needs to be done to the house to assess its needs and size an HP accordingly, and then design the plumbing end of things to set the HP up to succeed.

We'll work through the re-vamping of the piping and I'll keep you posted. I really appreciate all the feedback!

Thanks.

 

Remember, the issue is not not just inside the house, but if your PVC pipe indeed on has 0.75 ID, and that goes out to the pond, then the issue is the whole run from the pond and back.

 

Just to reiterate & reinforce what others have said:

1. The source side piping is too small; The internal diameter 1" PEX is equal to 3/4" COPPER OR PVC, you need 1-1/4"
2. That/those are not "pumps" in the true sense of the word, they are circulators designed to move fluid about in a closed loop. You need a submersible pump in the pond. In addition they are of cast iron body construction, they will become inoperable by getting fouled with rust in a fairly short amount of time.
3. Also, the desuperheater lines should be copper, not PEX, i've seen more than a couple burst when subjected to a shot of superheated water (+100C!) which desuperheaters can produce if the circulator gets momentarily seized.

You got hosed, it is evident the installer had no clue what he was doing, at the very least you should get a pro in there to do a proper lay-out for you even if you decide to tackle it yourself.

 

UPDATE!!

Okay, I just thought I'd bookend this thread for now because I hate reading threads that end with no known resolution.

The Geo Tech just left out property about an hour ago. I've removed the temporary submersible pump and have a shallow well jet pump installed, in-line, in the garage where the intake pipe enters. As we speak the system is cranking at 9 GPM and the house is at 70 degrees. The tech installed P/T ports on either side of the heat pump and the results are: intake water temperature = 44 degrees and 38 degrees outflow temperature. Intake pressure is 18 PSI and the outflow pressure is 14 PSI.

We ended up leaving the 1" PEX pipe in the garage, for now, but we re-vamped the route of the piping and eliminated 40 lineal feet of PEX pipe and dropped 8 - 90 degree elbows.

As it stands right now he's going to work with us and design a closed loop system for the pond with a heat exchanger. The plate-type heat exchangers I've seen online (SlimJim) would be cost-prohibitive for us. I'm hoping we can come up with an alternate plan for in the pond to close the loop as there was quite a bit of sludge in some areas of the pipe that we cut apart in various places.

He also flushed the system, in both directions, and was able to purge quite a bit of crap from the system and the water is now nice and clean.

Thanks for the time and effort to reply to this thread. I'll keep this thread updated into the spring/summer as to if/how we close the loop in the pond. Any further comment and/or suggestions are welcome.

That is all... for now.

 

Ooops, I forgot to mention the the 2 Grundfos circulator pumps are now gone from the system, as well. Just the shallow-well jet pump in the garage remains.

Thanks again!