Ground Source Heat Pumps

quattrokid

Thanks for your reply
The  ground loop in was around 1.5 degrees and out -1 degrees then during the cold snap,  but normally its higher  now around 4 degrees in 1 degree out ,I dont remember them being much different over the years ,the high delta temp  was less than the 7degree recommended I believe, and that was caused by a failing circulation pump but only happened periodically ,and also I have had the hoses clog up around the heat exchanger /three port valve  but have installed a spirotech  filter now . the cost as you say was quoted at  between £ 2-3K for the compressor ,but if it is the TEV maybe it is worth a try I think they want to sell me a new system really ! 

beardymarrow

Those ground loop temps are fine. High delta temp alarm wouldn't have kicked in at 7deg though. You're aiming for 7 to 10 deg delta and it'll alarm at 13. Could easily have been caused by the heat exchanger being clogged, circ pump or VXV though.

quattrokid

ok that is helpful info on the ground loop temps .
Thanks again 

beardymarrow

quattrokid said:

ok that is helpful info on the ground loop temps .
Thanks again 

No problem.
To be clear the High delta alarm is relating to the hot side (not the ground loop) so difference between GT8 and GT9. I should have made that two paragraphs so it was more obvious that the second sentence is talking about the hot side, not the ground loops.

ChapelBarn

beardymarrow said:

ChapelBarn said:

My electrical cassette error has happened a further four times this week even after resetting, suggesting an underlying issue - I assume cleaning the particle filter is the first thing to try.

I have a Greenline HT Plus C - the manual says that filter is located on the outside of the pump. Being a complete novice I want to check that I have the right valve before proceeding - would it be the one in the picture below? There appears to be only one for both heat pumps, would this be correct, as the error is only affecting one of them

Yeah, that's it, but I would have expected one for each pump. Mine is an E which has that filter inside the pump, but it also has an externally fitted one, so there might be another one on yours too.

OK - I' check again although not immediately obvious.

beardymarrow

ChapelBarn said:

beardymarrow said:

ChapelBarn said:

My electrical cassette error has happened a further four times this week even after resetting, suggesting an underlying issue - I assume cleaning the particle filter is the first thing to try.

I have a Greenline HT Plus C - the manual says that filter is located on the outside of the pump. Being a complete novice I want to check that I have the right valve before proceeding - would it be the one in the picture below? There appears to be only one for both heat pumps, would this be correct, as the error is only affecting one of them

Yeah, that's it, but I would have expected one for each pump. Mine is an E which has that filter inside the pump, but it also has an externally fitted one, so there might be another one on yours too.

OK - I' check again although not immediately obvious.

Was it the circuit breaker or the overheat tripping?

ChapelBarn

beardymarrow said:

ChapelBarn said:

beardymarrow said:

ChapelBarn said:

My electrical cassette error has happened a further four times this week even after resetting, suggesting an underlying issue - I assume cleaning the particle filter is the first thing to try.

I have a Greenline HT Plus C - the manual says that filter is located on the outside of the pump. Being a complete novice I want to check that I have the right valve before proceeding - would it be the one in the picture below? There appears to be only one for both heat pumps, would this be correct, as the error is only affecting one of them

Yeah, that's it, but I would have expected one for each pump. Mine is an E which has that filter inside the pump, but it also has an externally fitted one, so there might be another one on yours too.

OK - I' check again although not immediately obvious.

Was it the circuit breaker or the overheat tripping?

The circuit isn't tripping, although re setting the circuit breaker (off/on) clears the fault. So think it is the overheat tripping.

I find the reset button impossible to press - I know it is supposed to be very difficult, but was concerned about breaking it

beardymarrow

That shouldn't reset it. When you reset the circuit breaker does the button on the box at the bottom of the heater cartridge physically go in on its own? I'm guessing not and actually resetting the breaker is clearing the fault, but as soon as it needs to use the cartridge it alarms again because the overheat is still tripped. 

quattrokid

Hello beardymarrow 
I just wanted to share some findings related to my low pressure fault ,I found that on inspection the expansion valve was forming a frost layer on the outside which reading about this on the internet is not good ,possible low refridgerant ? but not sure, also the sight glass seems clear but no flow or ripples that I think I have noticed before, anyway as an experiment I cable tied some pipe  insulation to the valve and it has run with no fault for four days now if any light can be shed on this I would be grateful .
Thanks 

beardymarrow

quattrokid said:

Hello beardymarrow 
I just wanted to share some findings related to my low pressure fault ,I found that on inspection the expansion valve was forming a frost layer on the outside which reading about this on the internet is not good ,possible low refridgerant ? but not sure, also the sight glass seems clear but no flow or ripples that I think I have noticed before, anyway as an experiment I cable tied some pipe  insulation to the valve and it has run with no fault for four days now if any light can be shed on this I would be grateful .
Thanks 

Hi, frost on the expansion valve is normal for me. Whether it's normal or not in general I'm not sure, but I don't have any problems so I think it's OK. However if keeping that valve colder by putting insulation on it has stopped the alarms, then great. Just bear in mind if it's been warmer where you are (it is here) the last few days it could be the lower load helping too.