Heat Pumps - Some questions and advice!

Lex_Minimus

Hi everyone,

This post is in 2 parts, firstly to ask advice from anyone who has installed a Nordic GeoThermal Heat Pump (supplied by well water) and secondly to offer some advice based upon my own experience of trying to get the system working efficiently.

1. Advice Needed:

Currently our HP is being supplied by an old well, and it's at the limit of it's capacity, although we are able to maintain the 40ltr/min flow rate required. Even at this though, the HP will cut out either immediately or after 30 mins or so (red Warning Light appears). has anyone with expereince of the Nordic range come across this problem before?

2. Experience on installing/using the HP

This is more of a cautionary tale. We built an extension to our old farmhouse (200 years old), it was a highly insulated timber frame/block clad construction and we decided to go "Green" and replace our Gas central heating with a GeoThermal Unit on the advice of our plumber.

But.... It turns out you need a high degree of cooperation between the plumber, electrician and HP supplier, something which in hindsight I should have managed better myself. The upshot of this was that the HP was installed without all the necessry electrical points made available, and access to the electrical control panel was not possible because of how the HP had been installed.

In addition, the plumber negleted to inform us that the finishing tank had an internal immersion heater (unwired) for emergency hot water supply - only found this out after 3 MONTHS of no hot water!!!

And the plumber failed to conduct a survey of our well, simply reckoned we had sufficient supply - which we probably do not and may have to dig a new well.

All of this means that following the initial commisisioning of the system we do not have a fully working system for at least 3 months and the saga is ongoing, although there is light at the end of the tunnel... So my advice is:

1. Insist that your plumber or HP supplier performs a test of the well to ensure it will meet the requirments of the HP BEFORE purchase

2. Ensure that your plumber has previous experience installing HPs and troubleshooting them

3. Ensure that your plumber meets with your electrical contractor BEFORE installation to discuss the ESB requirements

4. Do not make a final payment to the plumber / HP supplier until the system has been fully commisioned and running to your satisfaction.

Sorry for the long post, but I hope my experience may save someone time, effort and money -

Cheers

Lex

yop

Lex - Excellent post as I can concur with your exact position!

Luckily I had planning in place and had informed all that I was putting in a heatpump and this meant that the heatpump and cylinder were put in the utility room ( I had to move the door!) and that it backed onto the closet which contained out UFH mainfolds and all piping to the upstairs.

I fairness I had got an email from the HP supplier to tell me what each trademan needed to supply, other wise I would not have been able to install.

How are you finding Nordic to deal with, personally I could not hack them at all, too much fluff about the size of their house, shed, office etc etc, more gaulling than helpful

The borehole is meant to have the highest COP if correctly installed, have you no comeback on this as you are probably talking the guts of 15k for that install I would reckon?

Lex_Minimus

yes, the planning and management let me down

Reserving judgment on Nordic for now!

Cheers

ciaran530d

Lex_Minimus wrote:

Hi everyone,

This post is in 2 parts, firstly to ask advice from anyone who has installed a Nordic GeoThermal Heat Pump (supplied by well water) and secondly to offer some advice based upon my own experience of trying to get the system working efficiently.

1. Advice Needed:

Currently our HP is being supplied by an old well, and it's at the limit of it's capacity, although we are able to maintain the 40ltr/min flow rate required. Even at this though, the HP will cut out either immediately or after 30 mins or so (red Warning Light appears). has anyone with expereince of the Nordic range come across this problem before?

2. Experience on installing/using the HP

This is more of a cautionary tale. We built an extension to our old farmhouse (200 years old), it was a highly insulated timber frame/block clad construction and we decided to go "Green" and replace our Gas central heating with a GeoThermal Unit on the advice of our plumber.

But.... It turns out you need a high degree of cooperation between the plumber, electrician and HP supplier, something which in hindsight I should have managed better myself. The upshot of this was that the HP was installed without all the necessry electrical points made available, and access to the electrical control panel was not possible because of how the HP had been installed.

In addition, the plumber negleted to inform us that the finishing tank had an internal immersion heater (unwired) for emergency hot water supply - only found this out after 3 MONTHS of no hot water!!!

And the plumber failed to conduct a survey of our well, simply reckoned we had sufficient supply - which we probably do not and may have to dig a new well.

All of this means that following the initial commisisioning of the system we do not have a fully working system for at least 3 months and the saga is ongoing, although there is light at the end of the tunnel... So my advice is:

1. Insist that your plumber or HP supplier performs a test of the well to ensure it will meet the requirments of the HP BEFORE purchase

2. Ensure that your plumber has previous experience installing HPs and troubleshooting them

3. Ensure that your plumber meets with your electrical contractor BEFORE installation to discuss the ESB requirements

4. Do not make a final payment to the plumber / HP supplier until the system has been fully commisioned and running to your satisfaction.

Sorry for the long post, but I hope my experience may save someone time, effort and money -

Cheers

Lex

Lex
I have a Nordic heat pump for two and a half years. Initially I had the 30 min cut-outs and after about 3 months had the immediate cut-outs.
I naturally blamed the heat pump (because it had shut-off) hit the roof on the phone with them, but soon felt extremely embarressed because they were so helpful even though I was hurling abuse at them, they calmly figured out where my problems lay and it was all solved over the phone. Embarressed because it turned out not to be a problem with the heat pump at all. These heat pumps it turns out have protection devices built-in and shut off if there's a problem somewhere on the heating system or the well water.
The first problem I had was the shutting off with the red light after about 20mins. This turned out to be a cross-threaded connection on a towel rail was letting air into the heating system. Whenever the circulating pump would come on it sucked a little air into the heating pipes and when it reached the circulating pump it slowed the water or got trapped there and the heat pump switched off and the warning light came on. This was happening because the gas pressure was going too high.
The immediate cut-out was similar to yours. I had 40litres/min but it started happening when the weather got colder. I called them again since they were so helpful the first time and they pointed to the well water. The flow rate was fine (if it was entering the heat pump at 12C) but the when the heat pump was off the water sitting still in the pipe coming from the well was cooling because it was so close to the surface. My builder said it was 3ft deep as Nordic had suggested but I decided to check and it turned out to be 6in down. I reburied it 3ft deep and never had to look at the heat pump since.
My house is 3,500sq ft and my brother and myself built the same design of house next to each other. He used a ground collector system (not Nordic) and his bills are between two and three times mine. It cost him just under Eur2000 less to put in but he's sorry now he didn't get the same system as me.
I am a retired Mechanical Engineer and I did a lot of research before deciding. Most of the others gave me customers to call (a bit pointless becasue they didn't know how it worked) but Nordic were the only ones who didn't do this but gave me a demostration on how it worked. Having had this I knew how to come up with questions for the others and none of them could give me the right answers. There was no BS from Nordic at all. They actually showed me how it worked, while the others just passed me on to a "happy customer". That still didn't answer my questions. With Nordic I got to understand it and they gave me the confidence that the others didn't that if and when I have a problem they'll know what's wrong.
I had problems not to do with the heat pump but that effected the heat pump and they were able to identify them and give me the answers even though it wasn't really anything to do with them.
You didn't say whether you were actually in contact with Nordic yourself. Did you call them? If not, you should. It sounds to me like all the problems you are having are more to do with the plumber than with Nordic. I paid for my unit and they had all the answers for my builder, electrician and plumber as they progressed through the building of the house. It all went together seemlessly. Sounds like your plumber and electrician just didn't ask the quetions? I would confidently say, to be fair that the heat pump is not to blame. I have found it very reliable, extremely efficient and the technical support second to none.
As for Yop's comment on their size of house, shed etc. I saw it all and it's big and there's a lot going on there, but I also saw sucessive ESB bills there and they're incredibly small, so I'd say any emphasis on size was to show the efficiency of the system.
Cheers
Ciaran

Lex_Minimus

Thanks Ciaran,

I had actually figured out the 2nd issue - cold water standing in the supply pipe. We've yet to complete the groundworks so a portion of in the supply pipe is above ground.... Will be adding a temp valve to flush the standing water as a workaround until the groundworks are finished.

I think you've hit the 1st problem on the head, I do indeed have an air problem with some of the legacy rads, will replace these asap to see if this alleviates the problem.

Once again thanks for the post, AND for your vote of confidence in Nordic!

shanea

HP on any heat pump stands for High pressure ( on the gas side). This is normally caused by poor flow on the heating side. This can be caused by as already stated, air in the system or by a failed circulating pump or by a closed valve either manual or motorised in the system.

Check the flow into the heat pump and then out there should be a rise of about 5 to 10 degrees C. Any more of a rise than that would indicate a poor flow. The heat pump then shuts down to protect itself.

shane

shanea

HP on any heat pump stands for High pressure ( on the gas side). This is normally caused by poor flow on the heating side. This can be caused by as already stated, air in the system or by a failed circulating pump or by a closed valve either manual or motorised in the system.

Check the flow into the heat pump and then out there should be a rise of about 5 to 10 degrees C. Any more of a rise than that would indicate a poor flow. The heat pump then shuts down to protect itself.

shane