@tim441 it's a Vaillant, I think the controls are probably not the best, but also not the worst.

Posted by: @scalextrix

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@tim441 it's a Vaillant, I think the controls are probably not the best, but also not the worst.

Based on owning a Vaillant and reading the manuals of others, I would say Vaillant are amongst the best controls.

The fundamental feature they have, shared with only a few others, is that changing the set temperature, whether manually or in a time program, shifts the WC curve.  This means that if the average person does what they are likely to do the system remains efficient.   The Ideal R32 models and oddly at least some Fujitsu's work very similarly, not sure which others do but I know plenty that don't.  Others work such that you can only program setbacks  (or set forwards) by bouncing off an on/off sensor/thermostat the rest of the time, or using some home grown kludge.

On top of this feature Vaillant controls have plenty of additional functionality.

For my money this, and the simple and natural way you program DHW and space heating, set the Vaillant apart from many other systems and are a good reason to recommend them.  I wish I had a comprehensive list of heat pumps with controls that work in a similar way.

@jamespa our tanks dated back to at least 1999 when we moved in, so I just assumed we would replace them.  The new tanks look much smarter and presumably have better heat insulation.  We have a plate heat exchanger, which is heating both tanks well.

There may be other costs associated with moving from vented to unvented.  We had two Aqualisa shower pumps, each of which pumped and mixed the water into a single pipe going to the shower.  These pumps are designed only for gravity fed systems, so we had to replace them with mixer units.  The units cost £500 each.  Since the showers were old, we decided on complete replacement.  This cost us £1900.

Posted by: @grahamf

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Since the showers were old, we decided on complete replacement.  This cost us £1900.

Ooch that's a lot. 

I replaced my pumped shower with a £80 hansgrohe mixer, and two pieces of coloured perspex costing £30 total forming a (much needed) shelf which also covers the old holes.  Drilled the holes through the wall for the pipes and mounted the mixer temporarily myself, plumber connected it up when he did the uPVC at no extra charge. 

I considered retaining my vented cylinder of a similar age to yours and one installer was quite happy to do that if I wanted, but convinced me to replace it.  He was right, the difference is well worth the cost.

@jamespa unfortunately, your plumbing and shelving approach wouldn't have worked for us - at least not in our en suite bathroom.  The single pipe is buried in the outside wall of a fully tiled bathroom.  Also, we like the luxury of turning on the shower remotely and waiting till it heats up, before we get in.  The new one tells us the temperature of the water and how long we spent in the shower - so more useless facts to obsess over. 

Out of interest, what advantages have you found with your new unvented cylinder?

Posted by: @grahamf

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Out of interest, what advantages have you found with your new unvented cylinder?

Previous was vented and I needed a shower pump and a very loud bath pump to get reasonable flow rates.  All gone.

All cold outlets in the house now potable.

Better heat retention.

Posted by: @jamespa

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Posted by: @grahamf

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You need to be confident enough to deal with the concerns of well-meaning relatives and friends, who may warn you that you are making a terrible mistake!

The oil industry sponsored right wing press has, without a doubt, done a fabulous job of convincing people that heat pumps are rubbish, albeith that the industry itself has made a fair contribution to this endeavour.  

They tried the same with EVs but appear to have been much less successful and are now even beginning to sound positive about them.

I can resonate with many of your comments based on my own experience.  The outcome was successful and the installation in practice straightforward, but finding an installer to quote a sensible price for a system that would do the job proved quite challenging.  Ironucally I ended up with someone very local, but got there through a very roundabout route.

When you do get to test please post back about your experience.  I trust that you have read about how best to operate them.  This is pretty much the polar opposite of how we operate boilers in the UK so you need to forget almost everything you learned about that!  Given your physics degree I'm sure you not only have but also understand why!

@JamesPa

I wouldn’t be so quick to say heat pumps and EVs are the way forward. For example, R32 heat pumps are already being called “bad”, are being phased out and will likely be deemed unfit within a year or so.

Has anyone actually worked out the carbon footprint of heat pump installations, including all the remedial work when systems are ripped out and redone? That’s a piece of the puzzle that rarely gets discussed.

On EVs, have a look HERE. To me, it’s not about scaring people, it’s about looking at the actual data and asking: are we truly going green, or just pushing green technology without the infrastructure and processes to support it?

In our case, we’ve spent around £50,000 “going green” so far, and likely more by the time our heat pump is fixed. Honestly, I would rather have pocketed the savings and not gone green at all. My kids’ future already feels bleak enough. I never even wanted children, partly because the world doesn’t care about their future and doesn’t value the people raising them. Both our employers treated us as if we suddenly were a liability, even stated “family difficulties” the moment kids came along, when all we wanted was a bit of flexible working.

Meanwhile, the real polluters, companies cutting down forests and operating on an industrial scale, aren’t being held to the same standard. And let’s not forget, countries like the U.S. emit at levels that completely dwarf anything “good old England” can balance out. If you imagine a swimming pool with 50 people peeing in it, and 10 decide to stop, does it really make a difference? Of course not. Either everyone does it, or it makes no impact at all.

And finally, one has to ask: are all these grants and incentives truly “free,” or will we end up paying for them in one way or another down the line?

Posted by: @drei

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I wouldn’t be so quick to say heat pumps and EVs are the way forward. For example, R32 heat pumps are already being called “bad”, are being phased out and will likely be deemed unfit within a year or so.

Has anyone actually worked out the carbon footprint of heat pump installations, including all the remedial work when systems are ripped out and redone? That’s a piece of the puzzle that rarely gets discussed.

Firstly can I say again that I am sorry to hear about your bad experience with your heat pump installation and I can understand that this makes you doubt the wisdom of changing to greener technology.

Nevertheless...

I believe what scientists say, not speculation or propaganda by self-interested parties or the biassed media.  The messages from scientists are unequivocal and equally unequivocal is the message that doing nothing is the most expensive option.

You can put you mind to rest on heat pumps.  R32 is less 'green' than R290 because of the gwp of the refrigerant.  But we are talking a few  kilos of refrigerant with a gwp a few hundred times that of carbon dioxide once on the lifetime of an ashp, as opposed to  tonnes of carbon dioxide for the gas you need to burn every year if you had retained a boiler.  The excess global warming due to R32 is equivalent to perhaps a year's saving due to not burning gas, in other words it's irrelevant.

The carbon footprint of an ashp won't be very different to the carbon footprint of a boiler or a fridge (similar components made of similar materials). So as a replacement for an ageing boiler or in a new build again not much different.  Throwing out a brand new boiler for an ashp may be a bad choice, just like throwing out any item with a good lifetime left (but we do it all the time sadly, just visit your local tip).

Regarding EVs that video is the sort of thing to ignore, it is made with an agenda and likely funded by the oil industry (it even comes with a health warning to that effect).  That said there are very legitimate concerns about the chemicals for batteries, although they are probably more about exploitation of people than carbon footprint.  My gut feeling is that the current breed of EV may be a necessary intermediate step towards ones with very different, perhaps organic, battery chemistry.  However they can't be developed (if they can be developed at all) without the incentives created by the market and the infrastructure to support them so they are adopted.  Of course EVs aren't the real answer anyway, the real answer is to cease using private transport, but people won't accept that.

The 'England is small' argument is difficult, but there again we are influential in the world (still) and also the sum of lots of small makes big.  The EU isn't small and we remain, thankfully, culturally aligned to the EU so I think it's fair to view us as part of that and therefore significant.

Your comment about not caring about our children (I have none) is certainly fair.  It's odd that, as a species, we have an urge to reproduce and protect our children while we are alive, but don't care a fig about what happens to them on a longer timescale than our own life.

Incentives are never free, they are paid from tax!

Finally I come back to my opening statement.  I believe what scientists say, not speculation or propaganda by self-interested parties.  The messages from scientists are unequivocal and equally unequivocal is the message that doing nothing is the most expensive option.  I'm basing my actions on that and so should government.

I have probably spent 40K on heat pump, solar panels and EV.  The solar panels have more than paid for themselves already, the heat pump will do so or thereabouts over it's lifetime, and anyway results in a much more comfortable house for which many people would pay a lot more for than I paid, even if there were no running cost benefits.  The EV won't pay for itself but neither would a replacement car for my old Mondeo have paid for itself, because cars are basically a very expensive item due to their vast depreciation.  If I subtract the depreciation that an alternative car would have suffered however, which is a fair comparison, and assume that the current tax incentives will evaporate, I guess it will break even.  Since the ev is a much better driving experience again a fair outcome.

Posted by: @jamespa

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You can put you mind to rest on heat pumps.  R32 is less 'green' than R290 because of the gwp of the refrigerant.  But we are talking a few  kilos of refrigerant with a gwp a few hundred times that of carbon dioxide once on the lifetime of an ashp, as opposed to  tonnes of carbon dioxide for the gas you need to burn every year if you had retained a boiler.  The excess global warming due to R32 is equivalent to perhaps a year's saving due to not burning gas, in other words it's irrelevant.

Yes, the 'global warming potential' GWP of R32 is quoted as 675 over 100 years, which means 1kg of R32 has the same global warming impact as 675kg of CO2, measured over a 100 year time frame. But some articles point out that this is potentially misleading, because R32 only remains in the atmosphere for around 5 years, measured over the shorter time frame of 20 years, the 20 year GWP of R32 is around 2300 - 2500.

Most heat pumps have somewhere between 1 - 2kg of R32, so that's the global warming equivalent of somewhere between 2,300 - 5000 kg of CO2 (20 year timescale) if the refrigerant leaks into the atmosphere. Burning gas releases 0.185kg of CO2 per kWh, so the heat pump leaking its refrigerant is equivalent to burning between 12,400 kWh to 27,000 kWh of gas - that's around 1-2 years of gas consumption for typical homes.

But of course, for the refrigerant, it all hinges on what happens to it and what proportion of heat pumps develop leaks, or leak over time, and how much gets recovered and safely destroyed.

Either way, over the 10+ year life of a heat pump its still better than burning natural gas, but a leak does take a bite out of the carbon savings, R290 looks the clearly better choice from a global warming perspective.

The other issue to consider, is in the EU they're planning to phase out R32 in 2027, not clear if UK will follow but as a small market compared to rest of EU, presumably UK will follow if only because the manufacturers will want model ranges they can sell to the majority of the European market.

What about this:

R32 ASHP

According to the new EU F-Gas Regulation, the sale of new heat pumps containing R32 refrigerant will be banned from 2027 onwards. I also noticed @Temperature_Gradient mentioning this in their reply.

@JamesPa it’s fortunate you managed to cover a heat pump, solar PV and an EV for £40k. Considering that an EV alone often costs around that figure, that’s a very good outcome.

My journey has been quite different. Our 12 kW Samsung ASHP with 19 radiators came to £22k. We had also commissioned the same installer (EPC Improvements) to do our solar PV and battery system (24 Longi panels + GivEnergy All-in-One for £25k), as that was always the plan. But once the heat pump started playing up, and the installer pushed back, we cancelled the solar + battery order. We lost about £164 due to the MCS insurance they had already paid (so they claimed). At the time I didn’t realise just how much sorting out the heat pump would cost, or how quickly the installer would wash their hands of it.

Eventually, I went ahead with solar anyway, and it turned out to be the best decision. I posted the EPC quote on the MoneySavingExpert forum (solar section) and was lucky enough to get help from Aviv, who gave me guidance and installer recommendations. The system I ended up with is a 20.55 kWp, 44-panel Eurener bifacial array with reflective paint and a 13.58 kWh GivEnergy All-in-One, all for the same price EPC had quoted me for just 24 panels.

The solar system has been a game-changer. It largely covers the ASHP’s “thirst” and still leaves us in credit. That said, due to the ASHP’s poor SCOP, we’re still around £1,200 a year worse off until the heat pump issues are fixed. Once they are, I’m hopeful the two systems will finally work well together.

If we eventually add an EV to the mix, things might balance even further, but by then, the total price tag of “doing my part for the environment” will be close to £100k. Also worth mentioning, that £50k so far wasn’t cash payment, we took out loans and maxed out multiple credit cards, simply because we wanted to do the right thing.

@temperature_gradient They'll all go to propane by 27. In our experience we find about 3 per year have a leak (out of 200+ we deal with) and about 4 per year that need the system broken into for repair, we cant speak for what other engineers do but the remaining refrigerant should be recovered and sent for processing.

@drei Your unfortunately so correct about the carbon footprint.  Ive been in the industry that I'm passionate about for nearly 50 years,  a boiler is cheap fairly simple and easier to recylcle or replace.    A heat pump is very complex with many unique expensive parts within it, I know, I've replaced many pcb's fan motors and a few compressors, plus the dreaded 4 way valve. Its a goldmine for the service/repair industry that for many customers will be expensive. For example if a compressor fails in year 8, if still available, youll need to change the main pcb £300 and compressor £1500+ and then pay an FGas engineer £1000 plus to fit it all and Re gas it. (plus vat)   If they decide to scrap it all and replace with a boiler (£2500) at least they'll have say a 3 year warranty and lower repair bills. Similar with EVs, but time will tell....

When you get a heat pump quote, ask how much the annual service cost is, how long is the warranty and some sample repair prices. Then speak to us and we'll tell you whether that seems realistic.  So called 'Green' is not just about a cheap install with a large grant.