Ground Source Heat Pumps

lovesgshp

Patrol wrote: »

OK, figures for this evenings DHW.
(my wife ran hot water for 2 minutes half way through before I realised)
would make little difference on a 300ltr tank!!

Started at 7.03pm, completed at 7.30pm.
That is too long, should be around 10 mins. Have you checked if there is air in the tank?
No additional heat.
Front panel off for first 20 minutes or so.
Valve A pipe warmed up quickly.
VAlve B pipe warmed up over 5-10 minutes.
There should be no change on "B" during the DHW cycle, but only as the valve switches back, when a temperature burst occurs

GT1 started at on 8C now 24.4C to on 8C now 23.9C
GT2 dropped from 14.6C to 14.1C
Only outside air temp, so normal
GT3 dropped from 47.8C to 47.1C before rising to 54.3C
normal, no problem
GT5 remained constant at 18.8C and 25.8C
GT6 started at 43.1% and reached 85% before ranging 70%-80%
GT8 started at 41.8C and rose steadily to 57.3C
GT9 started at 42.2C and rose steadily to 52.1C
GT10 started at 13.1C, dropped quickly to 9.6C then slowly to 8.9C
GT11 started at 10.2C, dropped quickly to 7.3C then slowly to 6.4C

Operating hours remained unchanged at 13950 / 900.

GT8-11 look ok.
Earlier post re the room sensor, leave at 5, but see my comment below.
You are still using 2hrs extra heat, have you seen when this is activating and on which cycle? It should not activate until the pump has been running for 1 hour.
There is a possibility the GT5 sensor is giving a false reading, but without putting a new sensor on, it is difficult to determine. That was the reason I suggested to set it to 0.

Patrol

I think the 2 hours additional heat was before doing the filters and valve. The GSHP was on far more than it should be and the house temperature soared which is why I realised there was a problem. Feels a lot cooler now.

I haven't checked for air yet, wanted to post a picture to check which bit above the cylinder to twiddle but as a new user that wasn't allowed. Don't know if you can get to it by pasting the below into a url.

i208.photobucket.com/albums/bb237/Gate70/DSCN3996.jpg

I'll see if I can find the installation booklet so I can reference things by the right names.

Edit:
So having spent a bit of time looking at the tangle of pipework I think the air is not removed from the DHW cylinder unit but from the two central pipes on the GSHP, marked as Supply DHW and Return DHW?

lovesgshp

Hi
Air bleed for the tank is a small brass knurled wheel on the front left of the top of the tank. Open it slowly, until first air and then water escapes, then close.

Patrol

I removed the front panel and had a look. I couldn't see anything obvious so feeling a bit dumb and decided to refer to documentation.

I have found the GSHP installation book but nothing for the cylinder. Looking online I can find this PDF, and although I checked 20-30cm or so lower down maybe I didn't check far enough down; was trying not to disturb the insulation material too much as it was dropping particles as I moved it.

From this diagram I suspect I should have found a second skin with the air bleed at point A on the PDF and the fact I didn't means I need to look at removing the insulation to get further down the tank?

e-si.com/downloads/Double%20Shelled%20IVT%20HW%20tank%20D300-160_en.pdf

lovesgshp

Patrol wrote: »

I removed the front panel and had a look. I couldn't see anything obvious so feeling a bit dumb and decided to refer to documentation.

I have found the GSHP installation book but nothing for the cylinder. Looking online I can find this PDF, and although I checked 20-30cm or so lower down maybe I didn't check far enough down; was trying not to disturb the insulation material too much as it was dropping particles as I moved it.

From this diagram I suspect I should have found a second skin with the air bleed at point A on the PDF and the fact I didn't means I need to look at removing the insulation to get further down the tank?

e-si.com/downloads/Double%20Shelled%20IVT%20HW%20tank%20D300-160_en.pdf

The air bleed, should be on the very top of the outside casing, not inside.

lovesgshp

Look at page 4 & 5 in this guide.

http://www.rorjour.se/ivt/dvb.pdf

Patrol

There is nothing on the top left side of the casing but there is a similar item on the top right of mine. It looked to join the cylinder in the same manner as item 1 on the top centre diagram on page 2 of the guide you referenced.


If you can use the two URL's I have posted maybe you can confirm. Point A on my lads Photobucket account.

Edit. So I opened that up and sure enough a few minutes worth of air popped out followed by a spit or two of water then nothing.

I remember the installer showing how to add more water, saw the sensor on that had dropped to 0 bar during bleeding so gently brought it back to 1 bar then checked I got water out of the bleed valve. Temperature has dropped from 54C to 52.7C as a result.

I assume I need to check what bar it should be set to and bleed it a couple more times in case there is any more air.

Readings are 13952 / 900 so 2 hours ground loop since 2.45pm yesterday. 1 bath, a couple of showers and some hot water in that time. I've got figures over the years so thought I'd compare.

17/04/09 to 15/05/09 averaged 4.07h + 0.14h
27/04/10 to 09/05/10 averaged 4.33h + 0.17h
22/04/11 to 14/05/11 averaged 2.68h + 0.05h. Noted as hot weather.
23/04/12 to 09/05/12 averaged 4.25h + 0.06h
21/04/13 to 10/07/13 averaged 4.63h + 0.26h

Will monitor for a few days as I think your advice will help trim consumption.

lovesgshp

If you are now getting a constant flow of water from that vent, then the air should all be gone. Now you need to check if the heating time reducees, as it is the outside tank that heats the inner unit.
Max bar 2.5.

Patrol

Thanks, much appreciated. I dread to think whether a callout would have made the same progress, and at what cost. Plus I've learnt a lot and that is even more valuable to me.

The red marker on the sensor is set to 1.1 bar, have increased to that. I can't see any reference to what it should be and not 100% about the marker because the one on my UFH manifold is set to 3 bar while my UFH reading is only 1.3 bar.

Will leave the cylinder to drop back to 48 rather than run hot water off so will be a few hours before it drops back. That way I can check if the cylinder is holding heat better too now it is full?

Patrol

Right, next DHW, similar time I'm afraid.
(no heating cycles in last couple of days that I've seen).

Figures are GT3 / 6 / 8 / 9 / 10 / 11

6.49pm: 47.9
6.52pm: 46.2
6.59pm: 46.3 / 69.2 / 49 / 43.6 / 10 / 7.6
7:00pm: 47 / 71.1 / 49.6 / 44.1 / 9.7 / 7
7.02pm: 48 / 74.3 / 50.6 / 44.9 / 9.6 / 6.9
7.06pm: 49 / 74.8 / 51.7 / 46 / 9.4 / 6.7
7.09pm: 50 / 80.3 / 53 / 47.3 / 9.2 / 6.6
7.13pm: 51 / 78.1 / 54 / 48.2 / 9.1 / 6.5
7.17pm: 52 / 81.9 / 55 / 49.1 / 9 / 6.4
7.22pm: 53 / 88.5 / 56.3 / 50.4 / 8.9 / 6.4
7:27pm: 54 / 74.8 / 57.3 / 51.6 / 8.9 / 6.4
7.29pm: 54.4 cutout

Valve b outlet remained cold until cutout then flushed warm
(outside unit, warmth I noticed earlier was feeling nearer the valve)

Checked cylinder, no air.
Readings 13952 / 900 (neither value incremented)