Posted by: @mike-patrick

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£280 it was better to consider a new ASHP given its age! 

Well thats clearly nonsense.  If a £280 pump failed in a boiler you would replace the pump, as you would in an ASHP.

Posted by: @bobflux

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These systems should work fine without requiring the user to become a part time heat engineer and plumber. Unfortunately, visits from the "tech wizards" are damn expensive, and one tends to lead to another, then another... at some point it becomes profitable to invest the time to learn just enough to debug it on your own.

You can diagnose most of the issues yourself if you have a service manual, access to installer settings, and a forum with people willing to help.

Sadly that's true of many things these days.  The skill of fault diagnosis has become increasingly rare as things have become less repairable.  Cars are just as bad, take a car with a fault into the workshop and basically most of the fitters (I will not dignify when with the title engineer, because mostly they aren't) will plug it into the computer and change parts until the problem goes away, charging the customer each time, without a shred of understanding. 

Posted by: @mike-patrick

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Our ASHP has a history and about 5 years ago we did have a new PCB, which cost then about £800.

I had to have a new PCB on a boiler and it cost £500, its probably the most expensive part because its model specific whereas most other parts are generic.  The boiler in question was very simple, I suspect a more modern boiler would have been more.

I think @bobflux has summed up the way to approach this in his post above here

Posted by: @editor

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If a major component fails out of warranty (for example the compressor or main PCB)

This is a bit off topic but mention of PCBs reminded me of an incident a few months back that may be of general interest.

We had a 5yo Bosch tumble dryer that failed out of warranty and the local repair guys said it needed a PCB which with installation was going to be £200+ and therefore not worth repairing.  Of course they wanted to sell me a replacement, and in the end I did go for a new one this time with 5 yr warranty.

But before deciding I searched for "PCB repairs" and found this company

https://getitfixedltd.co.uk/

which does repair PCBs as well as lots of small electronic appliances.  I read somewhere that they can often repair old hifi/electronic equipment that may be obsolete.

In the end I did go for new but only because the dryer was in a stack (above the washing m/c) and changing the PCB was a two-man job to get it down and opened up.

I can't see that they tackle ASHPs so this is more for general information than specific to this thread (or forum!)

Since my last post on this topic we've reached a conclusion.

The local Grant approved firm called in their "controls specialist" to run some electrical tests on the unit. They were essentially outsourcing this to another firm. Full marks to them for admitting they did not have the full technical expertise in-house. But slightly worrying you could be Grant approved without it. He was the first engineer to visit who actually opened up the unit and did seem to know what he was talking about.

Following his visit we received a quote for repairing the unit. This was for installing a new PCB and compressor (so the unit required de-gassing and re-gassing). It was the first time I had been told it was repairable so good news albeit at a £2k cost.

The above occured over several weeks during which I also sought quotations for a brand new system. To keep them all comparable I had restricted these to suppliers/installers of Vaillant units and on the basis that we would have a new water cylinder too. Our existing UFH pipework would remain. The quotes came in at from £11k to £14.5k.

Not surprisingly I went for the repair option. Part of me really wanted to get a new system. It would have addressed the poor design/installation issues that have limited the performance of our existing one. Also newer systems have better COP ratings (existing is only 2.6) and consumer controls. But even assuming an annual electricity bill saving of £1k (nice to have and achievable but still hardly life changing in the context of overall household running costs) the payback period would be many years.

The repairs have just been completed  (two months elapsed since the breakdown), just in time for me to switch off the UFH anyway as the weather improves. But heating the water will at least be cheaper than continuing to use the immersion heater.

There's no assurance as to how long the repair will last (although the work is guaranteed for a year) but if we get another 5 years out of this heat pump I'll be happy, then, to get a new one. Given the speed of technical progress today's cutting edge pumps will probably be, like mine already is, museum pieces.

Mike

Glad you got a resolution but £11k to £14.5k to replace the ODU and controls alone?  Really? What else were they proposing to do?  Seems a lot to me.  A £2K repair job after 10 years is not bad though.

Posted by: @downfield

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which does repair PCBs as well as lots of small electronic appliances.  I read somewhere that they can often repair old hifi/electronic equipment that may be obsolete.

I was a repairer at a 'Repair Cafe' a couple of weeks ago.  Amongst the items that came in were a 60 year old radiogram, a 2 year old Dyson hair drier and a coffee machine of similar age.  Guess which one was repairable!

Back in the 70’s and through the eighties, one of my responsibilities was to ensure that an open reel tape based ‘language lab’ remained in working order for the students to use daily. The system had been installed in ‘72 and was still in warranty when I took up my post in ‘73. Now the warrenty had been very vaguely worded by the manufacturers and I managed to wangle free servicing for some years after. One of the most common failures was drive belt failure; their service engineer became very adapt at extracting the snapped belts, applying a single drop of cyanoacrylate to one end of the broken belt and mating the two ends for a second or two - then refit the belt and the mechanics would run normally again!  Rewards, Toodles.

Posted by: @mike-patrick

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@jamespa Our ASHP has a history and about 5 years ago we did have a new PCB, which cost then about £800. That was on the recommendation of a different local Grant approved installer. But based on what I have since learned I now believe that was just the easy route for him. The error code at that time was one that indicates a drop in system pressure. That's usually caused by a leak somewhere (we've had a few of those) which can be fixed easily. My journey with the ASHP has been a bit like owning a yacht - it's been a money pit!

Sorry to hear.

Grant seem to be selling the R290 pumps very competitively these days. 

I wonder if the design of the model you have is still similar to today´s? 

@jamespa I have wondered if the grant that's available for new installations under the Boiler Upgrade Scheme is actually pushing installer quotes upwards (depends on the price elasticity of demand for heat pumps) so that part of the grant effectively ends up in the pockets of the installers, rather than the end customer.

If so then replacement of existing heat pumps, which don't attract a grant, will be relatively unattractive to installers compared with doing new installations, unless they jack the price up to give them a comparable return.

Mike

@mike-patrick + some installers focus on the spec/new build market and only do retrofit when time allows. 

Posted by: @toodles

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One of the most common failures was drive belt failure; their service engineer became very adapt at extracting the snapped belts, applying a single drop of cyanoacrylate to one end of the broken belt and mating the two ends for a second or two - then refit the belt and the mechanics would run normally again!  Rewards, Toodles.

You make a great point to the value of continuity in service operation! 😉 These days, the site manager may move around too much to keep such knowledge about warranties (in the odd case where they last more than a year or two). So no wonder most products are just thrown and replaced every few years.. 😳

So financially speaking you'd have been better off with a gas boiler 🙄 

@deltona …without any of the many advantages provided by the heat pump regime! Toodles.