GSHP poorly sick
Discussion
Woke this morning to see the warning light flashing on the internal thermostat on the ground source heat system. System says it has low pressure and, get this, the expansion chamber has imploded.
Plumber comes out and says the manifold chamber in the garden is full of ground water, but with a slight blue tinge, suggesting the refridgerant has leaked at the outside manifold.
Neighbour had the same imploding problem and it turned out to be a leak at the manifold at the boiler. He tells me he gets odd days when a room will go cold and then warm upagain. I have one bathroom floor where half the floor is cold and half is hot and hot water that varies in temperature day by day.
Suppliers and installers are meeting on site but are these GSHP systems prone to such major (and expensive)failures?
Plumber comes out and says the manifold chamber in the garden is full of ground water, but with a slight blue tinge, suggesting the refridgerant has leaked at the outside manifold.
Neighbour had the same imploding problem and it turned out to be a leak at the manifold at the boiler. He tells me he gets odd days when a room will go cold and then warm upagain. I have one bathroom floor where half the floor is cold and half is hot and hot water that varies in temperature day by day.
Suppliers and installers are meeting on site but are these GSHP systems prone to such major (and expensive)failures?
Assuming it is low pressure in the refrigerant side of things, then it is a leak (OK, it could be sensor failure but more unlikely).
Refrigerant leaks can be very difficult to track down. For technical reasons the most likely problem area is the heat exchanger, but in reality it could be anywhere.
It's possible the refrigerant has had die added to help in locating leaks, but this would be unusual.
As a matter of interest the heat pump should have the quantity and type of refrigerant shown on a label on the outside of the unit - what does it say?
Refrigerant leaks can be very difficult to track down. For technical reasons the most likely problem area is the heat exchanger, but in reality it could be anywhere.
It's possible the refrigerant has had die added to help in locating leaks, but this would be unusual.
As a matter of interest the heat pump should have the quantity and type of refrigerant shown on a label on the outside of the unit - what does it say?
caziques said:
Assuming it is low pressure in the refrigerant side of things, then it is a leak (OK, it could be sensor failure but more unlikely).
Refrigerant leaks can be very difficult to track down. For technical reasons the most likely problem area is the heat exchanger, but in reality it could be anywhere.
It's possible the refrigerant has had die added to help in locating leaks, but this would be unusual.
As a matter of interest the heat pump should have the quantity and type of refrigerant shown on a label on the outside of the unit - what does it say?
I will check but it is blue and the guy who installed it topped it up with the blue stuff before looking in the manifold chambers. Bit of a nightmare as the system suppliers didn't install it so are arguing with the developers over who should pay and both who are blaming the installers, the cold, the moon and anything else that falls to hand. Refrigerant leaks can be very difficult to track down. For technical reasons the most likely problem area is the heat exchanger, but in reality it could be anywhere.
It's possible the refrigerant has had die added to help in locating leaks, but this would be unusual.
As a matter of interest the heat pump should have the quantity and type of refrigerant shown on a label on the outside of the unit - what does it say?
We are running on the back up system which is far from acceptable and which didn't cut in when the GSP failed.
I have just called my solicitor to clarify responsibilities.
RedLeicester said:
Sols a good start, may also be worth flagging with your insurers on the assumption there will be an awful lot of bill and blame - also they may well opt to pay to get it fixed now and then start the arguments with developer / manufacturer / installers later as to who will cough up.
I am hoping as a 3 month old system that they can sort it out between them, but it is this issue ariound who has ultinmatel responsibility and I think it is th buioders who sold us the system as fit for purpose.Cogcog said:
The refrigerant on the boiler is R407C/2,3kg.
They are using blue Sentinel R500C refridgerant.
R407C is a common refrigerant that wouldn't run at high pressures when used in a ground source system, less likely to leak than R410A.They are using blue Sentinel R500C refridgerant.
Edited by Cogcog on Friday 6th January 15:12
Edited by Cogcog on Friday 6th January 15:39
R500C is antifreeze not refrigerant.
The antifreeze system runs at much lower pressures than the heat pump. Antifreeze say 3 bar, R407C maximum 35 bar. If the heat exchanger fails the R407C would overpressurise the antifreeze system which would then probably leak out of a safety valve (or elsewhere) - this could easily give problems with the expansion vessel. If there isn't a safety valve (and it isn't necessary) - the pressure would burst the expansion vessel - which would then leak.
In my opinion the problem lies with the heat pump heat exchanger - the easiest way to test is to check and see if it has the required amount of refrigerant - it takes about 30 minutes to remove all the refrigerant and weigh it (correct equipment essential).
The heat pump installer/supplier needs to diagnose the problem (and probably fit a replacement unit) - then the expansion vessel replaced, then the antifreeze system redone.
If you paid the builder for the system - he has to sort it out.
I only install air sourced heat pumps in NZ, but I've had a number of heat exchange failures where refrigerant has got into the water so I recognise the symptoms.
caziques said:
R407C is a common refrigerant that wouldn't run at high pressures when used in a ground source system, less likely to leak than R410A.
R500C is antifreeze not refrigerant.
The antifreeze system runs at much lower pressures than the heat pump. Antifreeze say 3 bar, R407C maximum 35 bar. If the heat exchanger fails the R407C would overpressurise the antifreeze system which would then probably leak out of a safety valve (or elsewhere) - this could easily give problems with the expansion vessel. If there isn't a safety valve (and it isn't necessary) - the pressure would burst the expansion vessel - which would then leak.
In my opinion the problem lies with the heat pump heat exchanger - the easiest way to test is to check and see if it has the required amount of refrigerant - it takes about 30 minutes to remove all the refrigerant and weigh it (correct equipment essential).
The heat pump installer/supplier needs to diagnose the problem (and probably fit a replacement unit) - then the expansion vessel replaced, then the antifreeze system redone.
If you paid the builder for the system - he has to sort it out.
I only install air sourced heat pumps in NZ, but I've had a number of heat exchange failures where refrigerant has got into the water so I recognise the symptoms.
It is the R500C they have been topping up the pressure vessel with! The label on the boiler says R407C 2.3kg, 33.8 bar, 12.2/15.2KW. R500C is antifreeze not refrigerant.
The antifreeze system runs at much lower pressures than the heat pump. Antifreeze say 3 bar, R407C maximum 35 bar. If the heat exchanger fails the R407C would overpressurise the antifreeze system which would then probably leak out of a safety valve (or elsewhere) - this could easily give problems with the expansion vessel. If there isn't a safety valve (and it isn't necessary) - the pressure would burst the expansion vessel - which would then leak.
In my opinion the problem lies with the heat pump heat exchanger - the easiest way to test is to check and see if it has the required amount of refrigerant - it takes about 30 minutes to remove all the refrigerant and weigh it (correct equipment essential).
The heat pump installer/supplier needs to diagnose the problem (and probably fit a replacement unit) - then the expansion vessel replaced, then the antifreeze system redone.
If you paid the builder for the system - he has to sort it out.
I only install air sourced heat pumps in NZ, but I've had a number of heat exchange failures where refrigerant has got into the water so I recognise the symptoms.
I am guessing and hoping therefore that it is a anti-freeze leak in the array although the neighbours problem turned out to be a leak at the manifold under the boiler, discovered after they had dug up his entire array looking for the leak.
The supplier is not coming out for a week (too many breakdowns).
Don't like the sound of the installer being too busy fixing problems.
Anyway, is the low pressure error code to do with refrigerant or water/antifreeze?
It would be an unusual system that would bring up a low pressure warning for the antifreeze side.
The major problem is that 99% of heating engineers or plumbers in the UK won't have a clue about heat pumps.
There should be a pressure gauge for the antifreeze system, which should be reading anywhere up to 3 bar - if the low pressure warning is for the heat pump this will be a simple switch somewhere in the copper pipes. If it is low refrigerant pressure it's a major issue.
If you wanted to have a fiddle you could pull the low pressure switch wiring off the board and check the heat pump then tries to work, running it for a few minutes low on refrigerant isn't a problem.
Are there any manufacturers details on the heat pump?
ETA but there are issues if the antifreeze isn't circulating properly, which is possibly what's happening. Not sure if the expansion vessel is the cause of the problem or the symptom.
Anyway, is the low pressure error code to do with refrigerant or water/antifreeze?
It would be an unusual system that would bring up a low pressure warning for the antifreeze side.
The major problem is that 99% of heating engineers or plumbers in the UK won't have a clue about heat pumps.
There should be a pressure gauge for the antifreeze system, which should be reading anywhere up to 3 bar - if the low pressure warning is for the heat pump this will be a simple switch somewhere in the copper pipes. If it is low refrigerant pressure it's a major issue.
If you wanted to have a fiddle you could pull the low pressure switch wiring off the board and check the heat pump then tries to work, running it for a few minutes low on refrigerant isn't a problem.
Are there any manufacturers details on the heat pump?
ETA but there are issues if the antifreeze isn't circulating properly, which is possibly what's happening. Not sure if the expansion vessel is the cause of the problem or the symptom.
Edited by caziques on Saturday 7th January 18:12
Sounds like the problem is with the ground loop and not a problem with the heat pump.
They should not have to keep topping up the ground loop with anything, unless there is a leak in it. Then they should be fixing the leak, not just topping it up all the time.
If the Low Pressure fault is shown for an internal fault with the heat pump, then it could be from the low flow through the ground loop, if there is low flow or airlocks the evaporator coil can freeze solid, and this could cause an LP trip on the heat pump.
Edit to add:
I've never seen an expansion vessel installed in the ground loop system, only ever on the internal heating side.
Pressure on the ground loop can often be pretty low, I've seen them registering less than 0.5 Bar and the system still working correctly, so it doesn't need to be as high as 3 Bar.
Also it would be worth checking what consentration the anti-freeze is, as if it is too diluted it will become thicker and not circulate and transfer heat correctly.
They should not have to keep topping up the ground loop with anything, unless there is a leak in it. Then they should be fixing the leak, not just topping it up all the time.
If the Low Pressure fault is shown for an internal fault with the heat pump, then it could be from the low flow through the ground loop, if there is low flow or airlocks the evaporator coil can freeze solid, and this could cause an LP trip on the heat pump.
Edit to add:
I've never seen an expansion vessel installed in the ground loop system, only ever on the internal heating side.
Pressure on the ground loop can often be pretty low, I've seen them registering less than 0.5 Bar and the system still working correctly, so it doesn't need to be as high as 3 Bar.
Also it would be worth checking what consentration the anti-freeze is, as if it is too diluted it will become thicker and not circulate and transfer heat correctly.
Edited by JM on Saturday 7th January 18:41
LP on the refrigerant side points to a leak, only solution is to recover refrigerant and weigh it to check the charge, if it is short you will need to locate the leak fix and replace with new virgin refrigerant (best not to top up with 407c as it is a blend and if it leaks you at differential rates which means the blend goes to s**t)
gareth h said:
LP on the refrigerant side points to a leak, only solution is to recover refrigerant and weigh it to check the charge, if it is short you will need to locate the leak fix and replace with new virgin refrigerant (best not to top up with 407c as it is a blend and if it leaks you at differential rates which means the blend goes to s**t)
No as I said, LP on refrigerant side could also be due to low flow in the ground loop.As there appears to be a leak from the ground loop, and a neighbour has had a ground loop leak, then that's the first place I would look. If the ground loop proves to be ok and the LP issue is still there, then I'd put gauges on the heat pump.
Cogcog said:
I noticed the show house pressure vessel was almost empty today too.
The other neighbour ended up with sort of leak under his boiler but the symptoms were the same: pressure vessel collapsing, low pressure warning.
Can you say what make the heat pump is?The other neighbour ended up with sort of leak under his boiler but the symptoms were the same: pressure vessel collapsing, low pressure warning.
Also can you confirm whether the low pressure warning is for the actual heat pump or for the ground loop circuit?
Can you also confirm that the pressure vessel, is an expansion tank/cylinder on the ground loop circuit.
Any chance you could take some photos?
Where about in the country are you? I'd take a look for you if your near me.
JM said:
Can you say what make the heat pump is?
Also can you confirm whether the low pressure warning is for the actual heat pump or for the ground loop circuit?
Can you also confirm that the pressure vessel, is an expansion tank/cylinder on the ground loop circuit.
Any chance you could take some photos?
Where about in the country are you? I'd take a look for you if your near me.
The pump is IVT.Also can you confirm whether the low pressure warning is for the actual heat pump or for the ground loop circuit?
Can you also confirm that the pressure vessel, is an expansion tank/cylinder on the ground loop circuit.
Any chance you could take some photos?
Where about in the country are you? I'd take a look for you if your near me.
I think the waerning wa sthe ground loop, as is the expansion tank. I have pics but probably need better ones.
I'm presuming these are three different systems.
On the middle pic, the white expansion tank looks physicaly different to the other two.
(not just not collapsed)
It looks like it is metal, I'm guessing the other ones look like plastic.
I've never seen a plastic expansion tank, and I've never seen an expansion tank on the ground loop.
(having said that, most of the ground source units I work on are bore holes rather than trenches, so expansion tanks may be for some reason used on them, but not bore holes)
If your unit has low pressure on the ground loop, I would not use it till the ground loop is repaired and then re-filled. The compressor can be damaged if run without enough flow through the ground loop.
On the middle pic, the white expansion tank looks physicaly different to the other two.
(not just not collapsed)
It looks like it is metal, I'm guessing the other ones look like plastic.
I've never seen a plastic expansion tank, and I've never seen an expansion tank on the ground loop.
(having said that, most of the ground source units I work on are bore holes rather than trenches, so expansion tanks may be for some reason used on them, but not bore holes)
If your unit has low pressure on the ground loop, I would not use it till the ground loop is repaired and then re-filled. The compressor can be damaged if run without enough flow through the ground loop.
JM said:
I'm presuming these are three different systems.
On the middle pic, the white expansion tank looks physicaly different to the other two.
(not just not collapsed)
It looks like it is metal, I'm guessing the other ones look like plastic.
I've never seen a plastic expansion tank, and I've never seen an expansion tank on the ground loop.
(having said that, most of the ground source units I work on are bore holes rather than trenches, so expansion tanks may be for some reason used on them, but not bore holes)
If your unit has low pressure on the ground loop, I would not use it till the ground loop is repaired and then re-filled. The compressor can be damaged if run without enough flow through the ground loop.
The plastic collapsed tank was , I think, the top up for the ground loop. The other 2 metal ones are, again I assume, expansion chambers for the system itself.On the middle pic, the white expansion tank looks physicaly different to the other two.
(not just not collapsed)
It looks like it is metal, I'm guessing the other ones look like plastic.
I've never seen a plastic expansion tank, and I've never seen an expansion tank on the ground loop.
(having said that, most of the ground source units I work on are bore holes rather than trenches, so expansion tanks may be for some reason used on them, but not bore holes)
If your unit has low pressure on the ground loop, I would not use it till the ground loop is repaired and then re-filled. The compressor can be damaged if run without enough flow through the ground loop.
The loop system is turned off and we are running on external source (electricity) until the 16th Jan when the builders, installers and suppliers all meet on site to decide what the problem is (and argue over who pays I guess). I confess I am losing confidence in GSHP, or at least this system.
Edited by Cogcog on Tuesday 10th January 14:47
Just some observations.
It is obvious to me that the system has been fitted by people used to fitting traditional heating systems ie everything is copper.
A heat pump will produce water at a maximum of 40c, hence I use plastic pipe and fittings everywhere. Much cheaper and quicker, copper is unnecessary and overspecified.
For a system of 12-15kW big circulating pumps are needed, 99w jobbies simply won't do (which it looks like are fitted). Again this is what conventional systems have - a heat pump requires large flows with small temperature rises across the heat pump. 10c is a maximum, I prefer nearer 5c - this won't happen with a small pump.
When working you should have maximum of 35c going into the floor, 25-30c coming out.
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