Hi @mark. Sorry you're having to step into this forum whilst in the midst of an industrial strike by your GSHP software!

I am not at all familiar with this HP, but I've search online and found technical reference manual for the Dimplex HP Controller.
This describes commands which can be given by a site-engineer which override normal operation whilst a particular maintenance/service routine is undertaken.

Amongst these commands I can find a reference to the heat-pump output (to the house) being 'blocked' whilst the service operation is being completed:

Since the manual suggests that the command times out after 24hrs, can you tell us for how long you've had the on-screen message?

@transparent thanks for the swift response. It does indeed seem like industrial action gets everywhere now!

It’s hard to know exactly when this screen appeared but seems within the past few days, possibly even today. The only two ‘trigger events’ I can refer back to for loss of UFH and hot water are 1 - someone taking a look at reducing the heat curve last week to help reduce heat as a) it was expensive despite only me being here and b) the floorboards were buckling in places. 2 - we had a power outage due to poor weather.  The hot water was luke warm yesterday then quickly going cold and the heating was steadily dropping in recent days and we increased the heatmiser temp despite outside weather getting milder.  2 and 2 going together led me to have a look at the heat pump this morning and I saw that message.

I am unsure about the word ‘block’ in this Dimplex set up tbh, as it seems contradictory in places but I’m very new to all this and just starting to learn the lingo!

@mark - here's a portion of the Trouble-shooting Guide at the back of the same technical manual:

Your particular GSHP model is discontinued, and much of the original documentation is no longer available.
But it looks to me as if this is a 3-phase system with two compressors in the main unit, and a secondary immersion heater which should take over if the HP itself fails.

The fault on your display is telling us that there is an electrical load 'out of specification' on the pump/compressor unit(s) which are driving the brine mixture through the external/ground pipe network.
So if Dimplex can't be contacted, you need a qualified electrician who works for a heat-pump installer.

If it were me, I'd be checking the voltage being supplied to the brine-pump to check if any of the three fuses have blown. It may be protected by a trip rather than a fuse, and this could be reset.

If the voltages are ok, then we check if the primary pump is rotating. Listen to it!
If it is, I'd clamp an ammeter on each phase in turn to see if the current being drawn is balanced.

Copy the above to any HP electrical engineer you can find because it will provide an initial route towards a diagnosis.

If you've had a power-outage recently, then that alone could've caused the safety breaker to 'trip'.
Is there an access door on the front of the main compressor unit which opens to let you see indicator lights, gauges and trips?

The manuals are translated from the German. I'm inferring that the word 'block' sounds more positive to them!
It's basically telling you that the system has shut-down to protect it from possible damage.
But it leaves the electrical circuits live so that the fault(s) can be found.

Once this hiatus is over we can discuss reducing the UFH water temperature and installing some surge-protection devices in the pump-supply so that they will absorb voltage/current spikes rather than a trip being thrown.

For engineered wooden flooring, the max temp at the floor surface must be below 28degC to avoid warping. I achieve this using 46degC leaving my ufh manifolds.
Solid-wood boards need a lower temperature.
But we need to have a more detailed discussion on your floor composition before we can start solving that issue.

@transparent wow thanks for that feedback, it’s super helpful for me to pursue.  There are so many dials and gauges, several motors working/not working (possibly by design) and various solenoids clicking around but I’ll have to dig much deeper.

I’ve also downloaded some documentation but as you say its now discontinued and this (so far) does not appear to be an area where older equipment is being well supported by the manufacturer.   My inexperience in this area also leaves me ripe for being exploited in what so far appears to be a market where firms want to install shiny new things but not worry too much about in life mgt and performance down the line.  Hence why I thought I’d also try and find a trusted forum to learn - and this first experience is a positive start so thanks again and Merry Xmas!  I’ll share back the results once I have got it sorted. 

@transparent I’ve looked at all the breakers I can find so far but will be digging deeper again tomorrow as my first thought was a tripped fuse/breaker. 

The former owner said there are surge protectors in the system and whatever else is required which then initiates an auto restart in the event of power outage.  It’s a very comprehensive set up.  The chap who was in last week turned down the heat curve to prevent the boards bending as he said the temp was nearing 40 but should be closer to 27-30 as you’d pointed out too. That change stopped the board bending and prima facie looked like it helped daily KWH reduction a bit.  However its not clear whether he might have inadvertently hit something else in turning the heat curve down. 

I should have mentioned that the flooring is an engineered oak board, about 22mm thick I think.  

Posted by: @mark

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Hi I’m Mark.  We’ve just purchased a lovely Edwardian property that had a substantial renovation 10 years ago including the former owner adding 40 solar panels in a ground array, a Dimplex SI TE 30 GSHP to service 5,000 sqft and underfloor heating with 25 heatmiser thermostats across the property in various rooms and zones. 

I’m keen to get even more into renewables and I’ve got a range of issues I’m planning on working through to improve efficiency & effectiveness, and prepare for another large extension next year. Finding this forum is great and I hope to be a regular!

However my GSHP has just stopped working and it shows the following message on the Dimplex heat manager software: load prim. side  block (see attached image)

 

 

I can’t get a response from Dimplex and the former owner, who is wonderful and stays in touch, has not seen that message before. 

Would anyone on this forum know what that message means, why it might be affecting the unit working, and what I need to do in order to rectify it quickly?  It was suggested I turn off the heat pump and turn it back on, which I’ve done, but the message comes back and the heat pump doesn’t operate as expected.

My wife’s family are supposed to be coming for Xmas but she has just left to find a warmer place until it’s fixed so I’m not too popular right now!

 

Many thanks for any feedback. Mark  

 

I would suggest switching off the power to the whole system for about 1 hour, to ensure that all capacitors are fully discharged. Then power the system back up.

@mark - I've found a technical overview of GSHPs from Dimplex which is worth scrutiny.

It clarifies some of the phrases which suffered in translation from the German. For example, when they refer to the primary (collector) circuits as being filled with 'brine', they don't mean that it's salty!
In Dimplex terminology, 'brine' is a mixture of water and ethylene glycol (anti-freeze). 😆 

@transparent morning and thanks for that.  You beat me to a post!  I’m pleased to advise that I’ve now found the fault and sorted it, and my wife has just told me Xmas can go ahead after all! Having reflected on your post and my basic knowledge of things i just went on an exploration this morning and tested all the fuses and breakers again.  Nothing wrong and it just didn’t make sense so I got brave and took the heat pump main cover off to see if there was anything obvious.  

There was a breaker in the middle of the heat pump (see photo)

that was unclear (to me at least) whether it was on or off so I just decided to push the button and see what happened.  It immediately jumped into life:) 

To be fair to Dimplex support too, they also replied quickly this morning to an email I sent yesterday, after waiting too long for a reply on something else - which they apologised for a delay on, so all good there too.

Thanks again for your help so far, your thoughts and interest gave me hope that there are people in this world who just want to help and when life can be shitty thats a good thing to hold onto! 

Merry Xmas and here’s to a more proactive focus on renewables for 2023 with less firefighting:)

I don't see any anti-surge devices in that photo @mark
They would normally have a substantial earth wire on one end.
They require as large a path to earth as you can afford. That's where they dump all the excess energy.

Your other possibility is to fit surge-suppression in your (3-phase) consumer unit, like I do.
That prevents all external surges, like lightning, from traveling through your mains-connected equipment.

I'm glad you've got your wife back for Christmas.
Add surge-suppression to the pressie wish-list. 🙂 

Roughly whereabouts are you in the country?
I'm interested to find out who is your Electricity Distribution Network Operator.

@derek-m hi Derek thanks for that suggestion.  I tried turning it off for a while but found later that it was indeed a breaker inside the heat pump per other thread comments, so hopefully will be fine now.