Ground Source Heat Pumps

ChapelBarn

I have two x GSHP installed along with a buffer tank and a step controller. I would appreciate some guidance on what is controlled on the Step Controller and what I can still control directly on the heat pump via the Customer and Service menus.


From what I can see the Step Controller is used for the Slope, Fine Tuning and Indoor Heat Senor setting. Whilst I my Greenline IVT operating manual, I don't have anything that explains how this interacts with the Step Controller and which one takes precedent over the other.

lovesgshp

Hi and welcome.
Firstly, will you please give me GT1 to GT11 readings for both pumps during operation.
High delta alarms could be due to a number of factors, so these can be worked through with a few tests.
1) Check the filters are clean.
2) Circulating pump speed may be too low.
3) 3 way valve sticking.(you need to manually test this).
4) Air lock in the system.


These are the most common problems, so check these first,

ChapelBarn

Hello and thanks for the reply.


I have checked the readings on each pump and they are as follows


Pump 1


GT1: now 49.1 (off 52.9)
GT2: -27.5 (* see step controller note below)
GT3: now 49.8 (target 50)
GT4: not on menu
GT5: not on menu
GT6: 84.3
GT8: 50.6
GT9: 43.1
GT10: 5.1
GT11: 44.8




Pump 2 (this is the one that experiences all of the alarms; it was in standby initially but then went into operation)


GT1: 42.5
GT2: -27.2
GT3: now 54.7 (target 50)
GT4: not on menu
GT5: not on menu
GT6: 63.3
GT8: 59.5
GT9: 53.1
GT10: 12.8
GT11: 35.6


Note that I also have a step controller which has the following readings:


Room Temp: 15.72
Outside Temp 3.34 (this is correct, it is not -27.2 as noted at GT2)
Rtn Temp: 40.88
Target Return: 38.80




Thanks also for the recommendations - some further questions about these



1) Check the filters are clean.> The system has just been fully flushed and a new magnetic filter fitted just above the buffer tank. Is this the filter I should be cleaning? The C series has an external filter and so Ia m not 100% sure what I am looking for.

2) Circulating pump speed may be too low.> From what I can see both pumps are set to maximum (in the full anti-clockwise setting)
3) 3 way valve sticking.(you need to manually test this).> OK - I can see where this is on the pumps, how would I test it
4) Air lock in the system.> Not sure how to diagnose or resolve this.


Thanks again
Patrick

lovesgshp

Hi Again.


Sorry for the late reply, but the storms here in Italy were knocking out the electricity supply.


I am going to ignore the step controller for the moment and just give some observations on the other readings etc.


1) You do have very large differences in the GT10/11 deltas. This could be due to faulty sensors. If you had HTF alarms, can you confirm if they are related to 10/11?


2) You need to check the filter from the ground loop to the pump. It should be a valve with a large hexagonal nut to unscrew after the valve is closed to check the filter.


3) As to your point re the normal filters, they should be above the heat pumps in a similar configuration to the above.


4) Is your ground loop pressure around 0.5-1.00 bar when operating and heating pressure about 1.5 bar.


5) To test the 3 way valves you need to go into the I/S menu and select manual operation of all, then scroll through that menu, till you get to 3way valve.


6) Air locks: There will be a valve on the top of each internal hot water tank which you can unscrew to release the air, until just water comes out. As well there should be air release valves at the highest points in the system.


Being blind as such on your system, I can only think of possible solutions, but hope these help.

ChapelBarn

Hi there - I saw the news about the storms in Italy, hope all now OK.


Thanks for the reply - to answer the questions below





1) You do have very large differences in the GT10/11 deltas. This could be due to faulty sensors. If you had HTF alarms, can you confirm if they are related to 10/11?


Having reviewed the log on the affected pump (pump 2), all of the alarms over the past 3-4 days were High Return HP (GT9) alarms - looking at the timings they seem to be occurring pretty much every 30 minutes the pump is in active operation (during the day it reverts to Summer Mode as the weather is reasonably mild). This was not the case a week ago, when I was experiencing High HTF Delta and Electric Cassette - but I scrolled through 20 plus alarm logs and all were the same.



The possible cause on the log for the GT9 alarm was listed as one of:



- Hot Water Temp Too High: My DHW is set at 40 degrees - although I have lowered it recently, having previously been set to 45 and before that 50)

- Radiator/UFH valves closed - checked and all are open
- Heating Set too high - I have decreased the heat slope to 2 (from 3 and before that 4)
- Flow of Heat Carrier is higher over heat pump than radiator - unfortunately my manual tells me to call Ice Energy if this happens



The other pump seems fine when checking the logs.




2) You need to check the filter from the ground loop to the pump. It should be a valve with a large hexagonal nut to unscrew after the valve is closed to check the filter.

I opened this and it was clear


3) As to your point re the normal filters, they should be above the heat pumps in a similar configuration to the above.


Likewise - these were clear, as I'd expect as I had my system fully cleaned a month or so ago


4) Is your ground loop pressure around 0.5-1.00 bar when operating and heating pressure about 1.5 bar.


It is operating within this range - doesn't seem to vary significantly, but is generally in the 1 - 1.25 bar range.


5) To test the 3 way valves you need to go into the I/S menu and select manual operation of all, then scroll through that menu, till you get to 3way valve.

Still working on this - I have found the manual operational of all, not yet found the 3way valve setting on the I/S menu



6) Air locks: There will be a valve on the top of each internal hot water tank which you can unscrew to release the air, until just water comes out. As well there should be air release valves at the highest points in the system.


I opened the valves and water came straight out, so no air locks appear to be in the system.


Thanks,
Patrick

ChapelBarn

One further thing that I have just noticed. Despite reducing the target DHW from 50, to 45 and now 40, the pump with all the alarms is showing the temperature of the water to be much higher - the GT3 setting was showing target 40, actual 58. This is consistent with the water coming out of my taps which I measured to be well above 40 degrees.

lovesgshp

Hi Patrick.


At the moment, this seems to be pointing to the 3 way valve, which is not uncommon.
You need to be in I/S menu 5.3 and scroll through the options until you get to the 3 way valve. It is there I can assure you, as have just pulled it up on the simulator.

ChapelBarn

Hi - yes I have now found the option. On both pumps the three way valve was not activated, I assume that I need to select "yes" to activate which I have done.


I'll keep take a look at the readings and alarms later today after they have been running for a few hours.

lovesgshp

In that setting, you need to watch the movement on the valve. It could be a lever or a dial that will move.
It is full movement you are looking for, so carry out the operation a few times.
What I am thinking is that the valve is sticking between DHW and heating, which could cause the high DHW temp.

ChapelBarn

Trying to post a picture of the valve but is keeps getting blocked.


However I see the issue - there is a red dial, on my good pump this rotates back and forth when I manually activate and de activate the three way valve setting. This was not happening on the pump I have the issues with.


I have used a screw driver to try to encourage it to move, this seems to have made some difference and having manually activated/de activated a dozen on so times it now appears to move on its own, albeit not as freely as on my other pump. Is this something that can be stripped and cleaned, or anything else to help prevent it sticking.


I'll try and post a picture again.