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?
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.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).
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.
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
caziques said:
100kW hrs a day!
Someone has some serious explaining to do.
Take 20kW hrs a day off for normal household stuff - leaves 80.
Heat pump should be at least 3:1, and in reality should be nearer 5:1. Anything from 240kWhrs of energy (ie 10 every hour of the day) or 400kWhrs a day of energy going into a new build house! You could this with fan heaters everywhere.
Things are a bit different in NZ as the day temperatures tend to be warmer (less heat loss), but I use air source (in theory less efficient) and invariably houses here have aluminium window frames (like having small radiators stuck in your walls) and are single story (much bigger surface area to volume leading to heat loss), but even so our heavy users consume half this amount under extreme conditions ie 40kW hrs a day for heating.
Someone mentioned about insulation, assuming all the pipes are inside the house leaving them without insulation means they act like a small radiator - as the idea is to get heat into the house it's generally a waste of time to insulate.
Something is very wrong. Although we are 4 adults we have had the GSHP set at 19 degrees, which isn't 'hot'.Someone has some serious explaining to do.
Take 20kW hrs a day off for normal household stuff - leaves 80.
Heat pump should be at least 3:1, and in reality should be nearer 5:1. Anything from 240kWhrs of energy (ie 10 every hour of the day) or 400kWhrs a day of energy going into a new build house! You could this with fan heaters everywhere.
Things are a bit different in NZ as the day temperatures tend to be warmer (less heat loss), but I use air source (in theory less efficient) and invariably houses here have aluminium window frames (like having small radiators stuck in your walls) and are single story (much bigger surface area to volume leading to heat loss), but even so our heavy users consume half this amount under extreme conditions ie 40kW hrs a day for heating.
Someone mentioned about insulation, assuming all the pipes are inside the house leaving them without insulation means they act like a small radiator - as the idea is to get heat into the house it's generally a waste of time to insulate.
The boiler ratio should be 3.5
I noticed that the boiler 'shower/hot water' light was often on when we were not taking water and put it down to the system filling the loop (as the house is quite large (3200 sq feet and almost 50 yards long so at certain times of day the system keeps hot water in the pipes so you don't have to wait for hot water to travel the 50 yards) but the loop is set on timer only for 7am-9am and 5pm-7pm.
And the washing machine has been plumbed into the hot supply rather than the cold! How basic a mistake is that? Shrunk my wife's best top. Not a happy girl.
I had estimated use of about 17000 KWHs a year based on the area and the fact we have a very good insulation rating.
Engineers here in the morning so will update then.
System was fixed but they couldn't figure out what the problem had been to lose the pressure/fluid. Seems fine now although I spoke with their technical dept because it was still gobbling electricity (178 KWH in the day after it was fixed). Turns out the settings were wrong and the system as ignoring the thermostat and just racing away, and the water/heating balance was also wrong. Monitoring for a week now to see how it goes.
JM said:
Sounds pretty poor commissioning of the system.
(Ice Energy ?)
I'd be keeping a close eye on the pressure gauge for the ground loop over the next week or two.
Maybe even keep a regular log of pressure readings and operating state and temps of the unit.
If you do, try and be as regular as you can. i.e same time(s) every day is better than frequent logs at random times, so for example, every morning at 8.00 and evening at 20.00 rather than one day 5 reading in the morning one in the evening, next day 2 in the morning 3 in the evening etc.
I will add pressure monitoring to my watch list, thanks.(Ice Energy ?)
I'd be keeping a close eye on the pressure gauge for the ground loop over the next week or two.
Maybe even keep a regular log of pressure readings and operating state and temps of the unit.
If you do, try and be as regular as you can. i.e same time(s) every day is better than frequent logs at random times, so for example, every morning at 8.00 and evening at 20.00 rather than one day 5 reading in the morning one in the evening, next day 2 in the morning 3 in the evening etc.
I have emailed the builder with my latest snag list today pointing out their liability to get this system working correctly, and the fact that I expect them to pay any extra electricity I have used. Some hope of that happening but you have to try ( I think it is about £400 more than the floor area suggests).
JM said:
I have dealt with clients who were tennants of a housing association, and they took electric meter readings before running their GSHP's for 24-48(+) hours on 'winter' start up/running, because it was felt that the builder/housing assoc should have had the system fully up and running before they moved in, in some cases months earlier.
To explan further the heat pumps were put on and ran by the installer and the builder switched them off after they were proven to work after being on for a day or two. So when the clinet took occupation sometimes weeks later, they then had to run them constantly again to bring the slab temps back up. They had been advised by the housing assoc only to run them for 2 or 3 hours at cheap rate electricity when they moved in.
I was called in to investigate why they "weren't working" and advised constant running for a day or two.
Not been back since.
We had it running at 23 degrees for a few months while the sale was going through (the sales manager liked it warm for prospective buyers) dropped it by a degree a day to 19 degrees for the floor to acclimatise and then turned it off for the wooden floors to be laid in late October for 2 weeksI then increased the temp by half a degree a day until we were back up at 19 degrees.To explan further the heat pumps were put on and ran by the installer and the builder switched them off after they were proven to work after being on for a day or two. So when the clinet took occupation sometimes weeks later, they then had to run them constantly again to bring the slab temps back up. They had been advised by the housing assoc only to run them for 2 or 3 hours at cheap rate electricity when they moved in.
I was called in to investigate why they "weren't working" and advised constant running for a day or two.
Not been back since.
A week in after the re-pressurising and things look OK. Header tank has dropped by about half an inch but is now stable, pressure steady. Spoke with the techy people again today who say things look well within the right ranges in terms of how much the compressor is doing and the heat outputs.
It has used 680 KWH in the last 6 days, so about £11 a day, and has averaged £12.33p a day over the past 3 months, including 11 days running solely on the leccy and a few heavy days warming up after the breakdown. I know we have had a mild wimnter so far but given that my summer use should be much less it may be within acceptable csost ove rthe year for 3000+ sq feet.
Monitoring for another 2 week or a month if it looks OK before ringing the techy.
It has used 680 KWH in the last 6 days, so about £11 a day, and has averaged £12.33p a day over the past 3 months, including 11 days running solely on the leccy and a few heavy days warming up after the breakdown. I know we have had a mild wimnter so far but given that my summer use should be much less it may be within acceptable csost ove rthe year for 3000+ sq feet.
Monitoring for another 2 week or a month if it looks OK before ringing the techy.
System has gone tits up again. GGGrrrrr
The plumber came to solve a problem with the ground floor bathroom only having heat in one half. He tinkered thought it had improved by an odd degree (using the digital thermometer). I think us thinking the groundfloor bathroom had warmed up slightly was just wishful thinking and it is the same ( 14 or 15 degrees).
Since he came out on the 26th January the system has been running quite wildly, especially the last 48 hours. It has used 867 KWH (about £105) of electricity since the 26th. The rads on the landing were running at 42 degrees and the bedroom between 25 and 34 degrees. The floor temperatures in most of the ground rooms have increased in temperature by 2 degrees. Then the ground loop system suddenly drained itself and threw a low pressure switch. Fooked.
Back up system has not cut in (again). Call out number denying all knowledge of the insurance cover arranged by the builder and anyway have no GSHP engineers on their list.
Just to add insult to injury I have just had an electricity bill for £2,163 for 3 months because Eon have had me on a quite expensive tariff from the builder and because they had overestimated the meter reading. When corrected, it is still around £1250 for 90 days.
Engineer came out today, refilled the loop with 200 lites of glycol. All manifolds pressure tested at 4 bars for an hour. Getting sand in the 3rd loop. He thinks there is a leak in the ground loop as the boiler seems to be working fine but he has adjusted the internal Also suggesting a powerflush.
The installation is looking questionable. Last resort is they install a new bore hole array, which the developers seem to be considering.
I am Notts/Yorks border and the system is 14kw driven by 3 phase electricity.
The installation is looking questionable. Last resort is they install a new bore hole array, which the developers seem to be considering.
I am Notts/Yorks border and the system is 14kw driven by 3 phase electricity.
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