Ground Source Heat Pumps

lovesgshp

I do not know what your outside temperatures are, but you can change the setting to for example cut the heating off at 16C outside.
If you are in DHW mode, also check if GT1 temperature increases, as this could point to the 3 way valve as well.
You do not need to pay £240 for a visit and a service!!

DeeWestern

lovesgshp wrote: »

Any updates DW? Have you, or are you going to change the 3 way valve?

I'm glad I ignored you for 3 months, your new experiment seems to have ruled out the 3 way valve being the problem and saved me some cash :rotfl:

Indeed, running just the hot water also seems to show that it's not a problem with the flow of my heating pipes in the house.

DeeWestern

So the system has been alarming even after the red tank has been repressurised and the hot water tank bled over the last couple of days.

As requested, I made sure the heating wasn't coming on, and turned the desired temperature of the hot water up to heat this up.

Minute	GT1 On	GT1 Off	GT8		GT9	 	Notes
0		24.4		25.9		48.2		40.1		Left pipe warm on 3 way, right hot
1		24.4		25.8		47.7		38.6		Right pipe goes v hot
2		24.4		25.8		51.9		38.5		
3		24.4		25.8 	57.5		38.5 	
4		24.5		25.8 	59.8		38.5 	
5		24.5		25.8 	62.6 	38.8 	GT8/9 Alarm
6		24.5		25.8		64.1		39.4		Left pipe gets warmer
7		24.5		25.8		65.2		40.1 		
8		24.5		25.8		66.5 	40.9 	Left pipe hot
9		24.5		25.8		67.1		41.6
10		24.6		25.8		68.1		42.5 	Left pipe too hot to touch
11		24.6		25.8 	69.0		42.8
12		24.6		25.8		69.6		43,1
13		24.6		25.8		70.2 	43.6 	Shutdown with GT8 HTF Out Max Alarm

The left (heating) pipe on the 3 way valve just feels like it was getting heat transferred from the other pipe, rather than water leaking through - it was much hotter closer to the 3 way valve then it was as the top of the machine - so I don't think this is faulty.
GT3 at minute 13 was Tgt 55.0, Now 59.1

lovesgshp

Thanks for the update. :beer:
As you seem to have eliminated the 3 way valve, then the other possibility is the GT8 sensor has gone faulty. This is not usual, although I have had GT10/11 with a high differential.
Unfortunately, I cannot check with our main engineer as he is on holiday as most Italians are in August!!!
You could get a electrician in to measure the resistance as per the table at the end of the manual and a new sensor should be around £30.
I will check with our engineer when he returns near the end of this month, as to what he thinks, unless you solve it earlier.

DeeWestern

Remember though we swapped the 8 and 9 sensors round and showed they were both OK earlier this year.

Might there be some problem with the big white tank that has all the water in it, or something associated with it?

The front panel seems to be fixed to it, not sure if there's anything to look at inside? This is what's on top, could there be anything wrong with the white container (I ask as that's about the only thing we haven't looked at )





If not, then the only thing I can think of is some other blockage inside the GSHP. Appreciate any thoughts anyone has, even if it is after their holiday!

lovesgshp

Is the white tank the pressure vessel for the mains cold water supply, as it is difficult to see where everything is going? If the mains water supply is going into that, at about 4 bar, then I cannot see any problem. If it was higher, then the pressure release valve would be actuating.
Do you want to wait until our senior engineer comes back in a couple of weeks to see what he has to say, or contact Alto again to get their view?
Apologies if I do not reply quickly, but one of our dogs was bitten by a viper here, so at the moment it is backwards and forwards to the vets!!!

beardymarrow

lovesgshp wrote: »

Is the white tank the pressure vessel for the mains cold water supply, as it is difficult to see where everything is going? If the mains water supply is going into that, at about 4 bar, then I cannot see any problem. If it was higher, then the pressure release valve would be actuating.
Do you want to wait until our senior engineer comes back in a couple of weeks to see what he has to say, or contact Alto again to get their view?
Apologies if I do not reply quickly, but one of our dogs was bitten by a viper here, so at the moment it is backwards and forwards to the vets!!!

I would assume that the white one is the pressure vessel for the DHW and the red for the ch?

DeeWestern

beardymarrow wrote: »

I would assume that the white one is the pressure vessel for the DHW and the red for the ch?

Yes, looks to be - but doesn't seem to be adjustable or checked in the same manner the red one can be. Really just clutching at straws as everything seem to be OK.

beardymarrow

DeeWestern wrote: »

Yes, looks to be - but doesn't seem to be adjustable or checked in the same manner the red one can be. Really just clutching at straws as everything seem to be OK.

It looks the same as mine, so the pressure can be checked with a car tyre pressure gauge (there's a valve on the top same as a car tyre valve). If low, can be pumped up with a car tyre pump. If it constantly loses pressure it'll need a new diaphragm. When I did mine a whole new tank was only a couple of quid more than the diaphragm so I swapped the whole unit rather than faff about trying to replace the internal diaphragm.

DeeWestern

On the basis it's a bit big to drag down to Shell, it it worth buying a car pressure gauge to see if this is a problem? What range should the pressure be?