@jamespa A High Loss Head?!😉

I'm honestly crossing my fingers, my toes, everything.

That the specialist comes, caps the top 2 ports, runs the flow pipe to the pipe to the heating direct around the top of the 50L buffer, removes the secondary pump.  Changes some settings.

Installs a new Grant panel, that's smart, not some 80s-90s style keycombo driven installer settings nonsense with code lookup to change settings.

Installs a digital flow setter.

Turns it all on.

And I see 21C in the white living room.  And going forward there's some easy way to see what is an issue, or I can simply make changes to the WC, check the COP, and get the system running as cheap and efficiently as possible.

And I never talk, nor think about heating ever again!

Posted by: @crimson

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I'm honestly crossing my fingers, my toes, everything.

That the specialist comes, caps the top 2 ports, runs the flow pipe to the pipe to the heating direct around the top of the 50L buffer, removes the secondary pump.  Changes some settings.

Installs a new Grant panel, that's smart, not some 80s-90s style keycombo driven installer settings nonsense with code lookup to change settings.

Installs a digital flow setter.

Turns it all on.

And I see 21C in the white living room.  And going forward there's some easy way to see what is an issue, or I can simply make changes to the WC, check the COP, and get the system running as cheap and efficiently as possible.

And I never talk, nor think about heating ever again!

I think you stand a good chance of this happening, other than  the never talking about heating again bit, once the interest takes hold its very difficult to shake off.

... and if it doesn't happen at least it should be obvious why

Posted by: @jamespa

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Posted by: @crimson

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I'm honestly crossing my fingers, my toes, everything.

That the specialist comes, caps the top 2 ports, runs the flow pipe to the pipe to the heating direct around the top of the 50L buffer, removes the secondary pump.  Changes some settings.

Installs a new Grant panel, that's smart, not some 80s-90s style keycombo driven installer settings nonsense with code lookup to change settings.

Installs a digital flow setter.

Turns it all on.

And I see 21C in the white living room.  And going forward there's some easy way to see what is an issue, or I can simply make changes to the WC, check the COP, and get the system running as cheap and efficiently as possible.

And I never talk, nor think about heating ever again!

I think you stand a good chance of this happening, other than  the never talking about heating again bit, once the interest takes hold its very difficult to shake off.

... and if it doesn't happen at least it should be obvious why

 

Thanks James, hope it comes to fruition.

I'll no doubt be back on here in 2026 winter time, asking about WC manipulation and balancing again, chasing lower electricity bills lol.

All I can say to everyone here is thanks for all the advice, hopefully getting to end of the journey.

Will report back how things go.

ASHP switched off per specialists guidance. Seems the blacked out flow setter I was reading wrong…There was zero flow on it. It’s on the return side. Specialist was very concerned.

So now I’m without any heating and no  hot water, without immersion runs to get that. 

He suspects PCB but not 100%. And is frustrated it wasn’t replaced Friday when installer had one to hand.

Am hoping builders approve him being employed and get him over ASAP.

Thank god its not too cold outside…

Saga continues.

PCB replaced by installer. In fairness to him was overwatched by builder and did his best, F5 error on panel. Couldn’t get it running. So now 2 days with zero heating and immersion hot water. Plus I think from Wednesday last week heating cycles barely ran..

Grant are sending an engineer themselves tomorrow morning as couldn’t get it working over phone with installer.

Specialist attending Friday to start full assessment and takeover of the system, replacing the installer. Already mentioned will look at balancing. And thinks know what the awful metallic bang is (that still happens when no ASHP is on and only secondary pump is running).

Am pushing for the 2 port conversion, no LLH on flow, 50L LLH becomes volumiser on return. And the new smart Grant panel plus a digital flow setter, and obviously secondary pump removed.

Me having to report what the ASHP is doing to people has killed my time. It should be remotely accessible with diagnostics for the specialist. And the blacked out flow setter was ridiculous.

That way he can monitor temps via Heatmiser app thats all setup (which I will ask the panels need calibrating as some rooms are reported 2C higher than actual!). Plus look at how the Grant is cycling etc. and finally get it running optimally.

Hoping this is the beginning of the end, 23 months after I moved in to this mess.  And I hope to see 21C in the rooms. And can sign this job off.

Frustratingly am off site tomorrow so other half has been given questions to ask Grant engineer.

My current thoughts are:

Wish I pushed harder in 2023 for installer to be replaced when wouldn’t select rads plus other issues

Wish I didn’t have a Grant ASHP as not impressed

That all sounds promising, the right people, who hopefully understand what they are looking at, are finally on the case.  Just one thought, if you are offsite when Grant visit perhaps you could consider a video/phone call?

Posted by: @crimson

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My current thoughts are:

Wish I pushed harder in 2023 for installer to be replaced when wouldn’t select rads plus other issues

Wish I didn’t have a Grant ASHP as not impressed

20/20 hindsight is wonderful.  I have almost, but not quite, trained myself to stop beating myself up for making mistakes in the past, on the basis that I can learn from them but cant retrospectively fix them! 

After the best part of 3 years on this forum, and having read quite a few of their manuals, I am still struggling to find a reason ever to recommend Grant.  The irony (and also comfort if you have a Grant heat pump) is that the heat pumps they resell are, from all accounts, perfectly fine.  Unfortunately they don't appear to understand them and possibly don't quite realise that.

The R32 Grant (actually from Chofu) was classic.  It was a heat pump that was, from all accounts good, to which they basically added some crude electro-mechanical box so that it looked, to installers, like an oil boiler.   Except that it wasn't an oil boiler so their 'added value' appeared to be precisely the opposite from a householder perspective.  Then, to compound the problem, they produced their hacked version of the Chofu manual with options removed, and, at least for a time, mandated or came close to mandating the installation of an LLH.  In most installations this would be unnecessary and, in the hands of an installer who didn't understand low temperature heating and the characteristics of heat pumps, performance-compromising.

I thought they had moved on by the time they released their R290 offering (Midea?), and perhaps they have.  However your story seems to show that some of the 'junk DNA' remains.

My suspicion is that a 'Grant' heat pump is absolutely fine in the hands of a highly competent installer (whether 'professional' or DiY), who knows when to ignore what Grant tells them and use the hardware as its original maker intended.  Unfortunately, it appears, Grant tried to appeal to the oil installer community, and the legacy lives on.  There will also always be people who think that just following the instructions without a shred of understanding (or in many cases care) will yield a satisfactory result, which of course it wont. 

I should restate that I am a mere consumer with an unhealthy interest in heating and a degree in physics, so its quite possible I have got it all wrong.  If someone wants to challenge my interpretation they are perfectly free to do so!

Posted by: @jamespa

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That all sounds promising, the right people, who hopefully understand what they are looking at, are finally on the case.  Just one thought, if you are offsite when Grant visit perhaps you could consider a video/phone call?

Posted by: @crimson

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My current thoughts are:

Wish I pushed harder in 2023 for installer to be replaced when wouldn’t select rads plus other issues

Wish I didn’t have a Grant ASHP as not impressed

20/20 hindsight is wonderful.  I have almost, but not quite, trained myself to stop beating myself up for making mistakes in the past, on the basis that I can learn from them but cant retrospectively fix them! 

After the best part of 3 years on this forum, and having read quite a few of their manuals, I am still struggling to find a reason ever to recommend Grant.  The irony (and also comfort if you have a Grant heat pump) is that the heat pumps they resell are, from all accounts, perfectly fine.  Unfortunately they don't appear to understand them and possibly don't quite realise that.

The R32 Grant (actually from Chofu) was classic.  It was a heat pump that was, from all accounts good, to which they basically added some crude electro-mechanical box so that it looked, to installers, like an oil boiler.   Except that it wasn't an oil boiler so their 'added value' appeared to be precisely the opposite from a householder perspective.  Then, to compound the problem, they produced their hacked version of the Chofu manual with options removed, and, at least for a time, mandated or came close to mandating the installation of an LLH.  In most installations this would be unnecessary and, in the hands of an installer who didn't understand low temperature heating and the characteristics of heat pumps, performance-compromising.

I thought they had moved on by the time they released their R290 offering (Midea?), and perhaps they have.  However your story seems to show that some of the 'junk DNA' remains.

My suspicion is that a 'Grant' heat pump is absolutely fine in the hands of a highly competent installer (whether 'professional' or DiY), who knows when to ignore what Grant tells them and use the hardware as its original maker intended.  Unfortunately, it appears, Grant tried to appeal to the oil installer community, and the legacy lives on.  There will also always be people who think that just following the instructions without a shred of understanding (or in many cases care) will yield a satisfactory result, which of course it wont. 

I should restate that I am a mere consumer with an unhealthy interest in heating and a degree in physics, so its quite possible I have got it all wrong.  If someone wants to challenge my interpretation they are perfectly free to do so!

Unfortunately this is the ONE day this month I can’t even arrange a call due to work commitments at the time. What I’ll do however is ask the other half if the engineer is ok to leave his number so I can give him a call later in the day, or ask if he can call me the following day.

Re the Grant. I think the first time I thought “what the hell is this??!”, was the installer explaining how to change the flow temp. That 3 key combination…then the codes…

That plus, the temp up and down on the  panel having no use normally and other buttons no use.

Then the hot water panel, 4 zones, only zone 1 is used. It’s frankly a load of crap.

How could that be considered a consumer level device??

I’m a technical person, so looking into things is fine, but can imagine a lot of people out there with these installed are beholden to installers/engineers just to do simple changes.

I truly hope I can get the smart panel installed and have something far more usable, and easily make amends down the line, not hover in a cupboard, remember which 21 XX code does what, and swearing that my sausage fingers don’t invoke the menu via the Grant 3 string chord.

I have a friend with an ASHP, think it was Samsung and he showed me the app. Just thought how I have I got something from the 90s!! And this cost THOUSANDS and mine is installed 2-3 after his.

I have the same unit and controller and it has been a journey of learning to say the least. After a terrible ECO4 install it has taken nearly 10 months to get the system to the point where it is easy to use. But that has meant building my own smart controller learning a ton and just adopting the “screw it I am going to try this” attitude. I am now in the position where I understand the system reasonably well but still have a ways to go. My unit is oversized which is making working everything out even harder, but I am getting there. 

All that said I am getting decent COPs, the house is warm and it is not costing me a fortune to run, I have full remote control over the unit and can see all of the  data in real time, I am working on automations to make it as efficient as possible  so I am getting there. I am also trying to make this repeatable so others in the same position can benefit from it as well. 

Posted by: @crimson

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I have a friend with an ASHP, think it was Samsung and he showed me the app. Just thought how I have I got something from the 90s!! And this cost THOUSANDS and mine is installed 2-3 after his.

The Samsung app is pretty user friendly, but has some limitations in its capabilities unfortunately.  At installer show the Samsung rep proudly showed me the latest all singing all dancing full colour version which...has the same limitations.  The Ideal UI is reputedly very good and the Vaillant which I have also.   There are several others in a similar category with both a tolerably good UI and a high level of capability.

However all of them still have lots of parameters which you can set, many quite obscure, reflecting in part the complexity that is a modern heating system and the vast variability of houses and in equal part poor translations from the original language, 'technospeak' or just imprecise descriptions of what they actually mean which have to be 'reverse engineered' by the community. 

Some of course are hidden behind the installer menu, but that creates a problem in itself, what do you want the householder to change, what does the householder need to change even though you probably wouldn't want them to (the WC parameters fit into this category IMHO), and what can, in actual real life, be left to installers (very little at present!).

In fairness modern boilers have pretty complex controls too with almost as many parameters (in fact Vaillant use the same UI for both boilers and Heat Pumps).  But there is much less of a tendency to optimise these because we have got used to the 'brute force' method of whacking everything up as far as it will go and using thermostats to time slice.  This isn't efficient or even particularly comfortable, but we nevertheless accept it with boilers whereas we dont with heat pumps.

Im not sure what the solution is to this TBH.  The complexity is inherent in the variety of houses and so has to exist somewhere (much like control panel has to exist in Windows, and 'Settings' in Android etc).  I cant imagine AI successfully configuring a heating system yet (who would it train from?), and anyway the processors in heating controllers aren't up to the task, and would you want to rely on cloud configuration of your heating?  The likes of Havenwise (still a cloud system) certainly are part of the solution.  I suspect combining the best ideas in all of the controllers would yield a significant improvement, but that would require manufacturer cooperation on a scale that is unlikely unless mandated by regulation.  A mandated standard API would be a big step towards this, separating control from hardware.  Its been discussed apparently, but I dont think there is a concrete implementation date.  This, I suspect, would need to be EU-wide to have any chance of being cost effective/adopted and anyway its the EU that are best at such things.

I wish you luck with the today and the next few days.  With people who understand it (as opposed to people who just follow instructions, if you are lucky) it should hopefully get fixed.  

I've been following this thread since it began, and it's very disappointing that the installers, and follow-up trade still haven't sorted your issues out.

A few things @jamespa said really echo how I feel about my own Grant - decent unit ruined by lack of understanding expressed in the installtion guide, and hampered by dreadful control panel, and too often, shoddy installation and handover. It's been over 2 years since mine was installed (or "added to the fabric of the building" might be more accurate) and I've just about got it performing now, but that's after building my own monitoring and control system (the "three button press for 5 seconds" is ridiculous), and working at it for month after month.

One thing that's made my head hurt more than usual is trying to figure out how a zoned building can be supported. I don't really see how a Grant (with essentially fixed flow rate from the HP and the "recommended" LLH) can work correctly in a zoned house, even if you have 2 identical zones you still have 3 modes of space heating - zone 1, zone 2, or both. I find that my zone 2 (upstairs ... in a dormer bungalow) is totally overpowered by the HP when only it is being heated, because the flow rate is much too high, and there's nothing in the Grant set-up to support a PWM signal to the circulation pump, nor anything to suggest this idea in the Installation Guide. 

As pointed out, the Installation Guide really highlights how little Grant seem to understand about the (Chofu) unit they sell (and are still selling I think). Ironically the Installation Guide for their LLH seems to make more sense, and they even suggest a better way of handling a 2 zone set-up: 

- by using 2 feeds out of the LLH you could have separate secondary circulation pumps for each zone, set to a flow rate appropriate to the energy demand of the zone. You'd still have mixing issues across the LLH, but at least you'd be exploiting what the LLH provides, rather than having to work around it. Of course, this example is only mentioned in the LLH guide, and not shown at all in the HP Installation guide itself, and I think @crimson doesn't have a Grant LLH, so that's not an option in their case.

Posted by: @mikefl

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One thing that's made my head hurt more than usual is trying to figure out how a zoned building can be supported. I don't really see how a Grant (with essentially fixed flow rate from the HP and the "recommended" LLH) can work correctly in a zoned house, even if you have 2 identical zones you still have 3 modes of space heating - zone 1, zone 2, or both. I find that my zone 2 (upstairs ... in a dormer bungalow) is totally overpowered by the HP when only it is being heated, because the flow rate is much too high, and there's nothing in the Grant set-up to support a PWM signal to the circulation pump, nor anything to suggest this idea in the Installation Guide.

This problem occurs, to a greater or lesser extent, with any heating system really whether ASHP. Oil or Gas and isnt special to Grant in the ASHP world.  The underlying issues are that none of these are capable of outputting water at two flow temperatures simultaneously, our houses anyway don't react instantly and rooms share heat whether we like it or not.

With boilers we 'overcome' the problem (in our minds at least) by whacking up the flow temperature to way above that actually necessary, and having zone stats switching on and off, at the expense of both efficiency and comfort.  With an ASHP zone stats and high flow temps are deprecated so thats not really a solution.

Fundamentally we have to step back and ask the question 'why bother with zones anyway?'.  In most cases separately time controlled zones are unnecessary, wont save money and wont add to comfort.  Sure we want bedrooms cooler than living rooms, but rarely is there a need for that to vary during the day, the bedrooms could just be cooler all the time.  For these cases separate time control of zones isnt required, the solution is (a) to design the emitters to get the right temperature differences as best as possible and (b) adjust the flow through (which you can do with a flow restrictor without having separate feeds or pumps) to 'balance' them for the desired temp difference (rather than for equal deltaT.).  No need for separate pumps, no need for an LLH, just one water pump (usually the one in the heat pump ODU) directly connected to appropriately balanced emitters.

Of course there are some cases where there is a genuine need for time variable control is a room, for example a room that is used for living in during the day and sleeping at night.  However in many houses the need may be there, but unless you employ active cooling on days when you are otherwise heating, no amount of control will achieve what you ideally want, whether with a boiler or ashp.  Very few rooms in any tolerably insulated house will cool from (say) 21 to (say) 18 in a couple of hours, it just isn't possible.  Nevertheless we console ourselves by fitting controls (eg smart TRVs) that don't actually work (because of the characteristics of the house), but do make money for the control manufacturers. 

In the probably rare circumstances where such control does work in a particular house (which will typically be a high loss house, a house where the internal insulation is as good as the external insulation and doors are shut) then a smart TRV on an ASHP for a room or two isn't going to hurt materially giving the desired time variability of temperature.

I guess what Im saying is that you can design out the problem in most, if not all, cases.  Of course that still isn't a reason to have the LLH in the first place!

FWIW I run my house on a single zone, with the LSVs on the bedroom rads (which are actually oversized relative to the living room rads, for historical reasons) turned down to restrict the flow, and thus temperature.  All but one of the TRV heads are unscrewed completely, ie the 'TRV' is doing nothing.  I don't achieve 3C difference in temp between bedrooms and living rooms, but then I didn't with my gas boiler because the bedrooms are upstairs (heat rises!) and we usually leave the doors open.  However I do achieve sufficient difference for comfort. 

At various times with my gas boiler I tried various 'smart' control schemes, none of which actually worked in a way that was worthwhile.  I therefore had already 'dumbed down' my controls by the time I fitted an ASHP.  I have come  to the opinion that we have been brainwashed by the manufacturers of heating controls into micro zoning in time and space, which we mostly don't need and mostly doesn't save much if any money.  My house has never been more comfortable and my heating never cheaper (adjusting, obviously, for the rise and fall of energy costs).