I also recognise that the Inverter capacity can limit useful storage.

I have lots of screenshots under different conditions but will just include 2 here and would appreciate comments.

We live in the countryside (beautiful, yes) but every few weeks we get absolutely smoked out by what I can only assume is industrial-scale burning from neighbouring farms and a garden centre. This weekend has been horrendous. Forty-eight hours of thick, acrid smoke filling the entire valley. Every window in the house shut all weekend. Our bedroom air purifier on red, continuously, for two days straight. Both my wife and I have had splitting headaches and we feel ill.

And I'm not talking about a pleasant woodsmoke smell here. It starts that way (maybe) but then the colour of the smoke changes and it gets greyer and darker and the smell turns chemical and honestly quite revolting. I'd put good money on plastic and/or chemicals going into that fire. Which means we're breathing toxins. PM2.5 particulate matter. Whatever other poisonous rubbish is being chucked on there.

What really gets me is the timing. It doesn't happen every weekend. Every few weeks. But it almost always starts on a Friday afternoon. Always. And it's always done and dusted by Monday morning. You don't need me to join those dots. If you're burning legitimate waste within the rules, you don't need to wait for a Friday afternoon to do it. They know exactly what they're putting on that fire and they know exactly why the weekend suits them.

I called the authorities this weekend. Twice. I won't bore you with how that went.

But here's the thing that is driving me insane. We live in a country where ordinary homeowners are made to feel guilty about everything that burns. Wood burning stoves are practically a moral failing now. We debate biomass carbon accounting. We're all being pushed toward heat pumps and clean air and net zero. Rightly so. But apparently none of that applies if you've got acres of fields. Then you can just burn whatever the hell you like all weekend while your neighbours choke, and nobody in authority seems to have the slightest interest in doing anything about it.

It's absolute madness. Has anyone else dealt with this? And does anyone actually know if there's any real recourse, because right now it feels like there isn't any.

* 6 x Ecoflow plug-in batteries, including 2 × EcoFlow Stream Ultra X 3.8 kWh, 1 × EcoFlow Stream Ultra 1.92 kWh, 3 × EcoFlow Stream AC 1.92 kWh, for a total of 15.36kWh, fed by various DIY solar panels totalling 2.98kW.

While the SolaX and Ecoflow aren't integrated and don't "talk" to each other, we use Home Assistant, Wonder Watt, plus an Ecoflow CT-clamp smart meter, and 2 x Shelly CT-clamp smart meters to monitor and manage the home usage.

In terms of energy draws, we're running a Nissan Leaf EV, and a Hyundai IONIQ PHEV, and a Daikin ASHP with hot water tank (and Solar iBuddy).

We have an 80A grid connection, and use the Octopus Intelligent Go tariff, with an Ohme Go Commander smart charger and an Ohme (dumb) EV charger. This setup works well and gives us 2330-0530 "cheap" energy (8p kWH) and some nice bonus "cheap" slots during the day (which WonderWatt takes advantage of to top up our batteries).

This will be the first full year that we'll have had the above setup running, but in previous winters, the batteries didn't cover peak-time use of 35kWH during the day, peaking at 50kWH.

So, we're exploring options to expand our battery setup to completely time-shift energy use, even during the coldest, darkest winter days.

The challenge is:-

* We cannot upgrade the Solax battery system, as it is both loft-installed and our existing installer isn't interested in lugging any more heavy batteries into the loft or for building safety regulations.

* The Ecoflow system is limited to 6 x batteries, which we've already maxed out.

* We have no more space for batteries inside our home, so are looking to outdoor units.

Therefore, I'm wondering what our options are to add an additional 30kWh (or similar sized) IP56 rated battery system to an outside wall.

I've been drawn to the Fogstar Energy 48V 40.96kWh IP56 Outdoor Battery System and Cabinet combined with a Victron inverter, but I'm sure there are other options.

Our challenge is finding an installer who will work to combine a new system with an existing setup. Most installers seem to want "green field" sites where they can install a standalone system. Therefore, a secondary question would be, which technically competent and experienced installers (we are based in Newcastle-upon-Tyne in the North East) would forumites recommend for more complex installs.

I appreciate the above is a fairly comprehensive setup, so feedback and suggestions gratefully received!

On paper, burning wood to heat your home is a renewable act. A tree grows, absorbs carbon from the atmosphere, is felled and burned, and another tree is planted in its place. The carbon released returns to the cycle. Nature's balance is maintained. It is a reassuring narrative, and it underpins billions of pounds of UK energy policy.

It is also, in significant part, a fiction.

The fundamental problem with the carbon neutrality claim made for biomass is not that it is entirely wrong... it is that it is only potentially true across a timescale that has almost nothing to do with the climate emergency we are currently living through. A carbon debt is created as soon as biomass is burned. If the expected regrowth happens, it will take anywhere from decades to centuries to pay back that debt, depending on the type of wood burned and the ecosystem from which it was harvested. In the meantime, that carbon is in the atmosphere, warming the planet right now, today, in the decades that are supposed to be vital for meeting the Paris Agreement's 1.5C target.

Research compiled by Penn State in the United States found that carbon payback periods for forest biomass energy projects range from zero to 8,000 years, depending on factors including the type of forest, the fossil fuel source being replaced and whether natural disturbances are factored into the models. Zero to 8,000 years! The government grants biomass a renewable designation and hands you £5,000 toward the cost of installing it. Read that juxtaposition slowly. 

The European Academies' Science Advisory Council has stated bluntly that carbon emissions per unit of electricity generated from forest biomass are higher than from coal. Burning wood is less energy-dense than coal, meaning more fuel is needed to produce the same energy output, releasing more carbon dioxide per kilowatt-hour at the point of combustion. The only way forest biomass comes out ahead is if you count trees that have not yet been planted as an offset against carbon that has already been released. Madness.

What the Government Actually Classifies Biomass As

The UK currently designates biomass as a renewable energy source, meaning it qualifies for support under the Boiler Upgrade Scheme, the same programme that funds heat pumps. The Boiler Upgrade Scheme offers a £5,000 grant toward a biomass boiler installation, though with significantly tighter eligibility criteria than heat pumps: the property must be both in a rural location and off the gas grid. Self-builds are explicitly excluded. The biomass boiler must carry a valid emissions certificate demonstrating that particulate matter and NOx emissions are within prescribed limits.

That emissions certificate requirement exists for a reason, and it points to the second major problem with domestic biomass that rarely features in the marketing materials.

The Air Quality Problem

Domestic burning through wood burning stoves and solid fuel appliances now makes up the single largest contributor to national emissions of fine particulate matter in the UK. Short and long-term exposure to wood-burning pollution has been associated with chronic respiratory diseases, heart disease, pulmonary function deficits, lung cancer, developmental abnormalities, and harm to the lungs, kidneys, liver, nervous system and brain.

A 2025 study published in Scientific Reports found that residential wood burning significantly increases short-term exposure to ultrafine particles, PM2.5, black carbon and carbon monoxide, with all types of wood-burning appliances (including modern eco-design models) posing potential health risks. The researchers concluded there is a need for health-focused strategies when considering wood burning for domestic heating.

Modern pellet-fed biomass boilers are substantially cleaner than log-burning stoves or open fires. That much is true. A well-maintained system burning dry, quality-grade wood pellets and serviced annually will produce emissions vastly lower than an old stove burning wet logs. But "substantially cleaner than the worst-case scenario" is a low bar, and one that the industry has made considerable use of.

What MCS Says... and What It Doesn't

MCS certifies biomass boiler installers under its standard framework. The MCS certification scheme covers biomass alongside solar PV, heat pumps, wind turbines and battery storage, certifying installation businesses rather than individual engineers and requiring adherence to MCS installation standards. MCS's own data dashboard puts the average installed cost of a biomass system at just under £19,000 in 2025, before the £5,000 BUS grant brings that down to around £14,000 for eligible properties.

What MCS does not do (and this is important) is adjudicate on the fundamental question of whether biomass qualifies as genuinely renewable. That classification is a matter of government policy, not MCS certification. MCS certifies the installation. The government decides what counts as clean. Those are two entirely separate decisions, and the gap between them is where much of the confusion lives.

The MCS Standard MCS 040 covers planned and preventative maintenance of biomass appliances. Research underpinning that standard found a 15% difference in in-situ performance of biomass boilers, primarily caused by poor fuel quality, lack of operator knowledge and inadequate maintenance. A 15% performance gap driven by basic operational failures is a significant finding in a technology being promoted with public money to households who may have limited technical knowledge. It also echoes, uncomfortably, the broader pattern of renewable heating installations that look good on paper and disappoint in practice.

Where Biomass Does Make Sense

Renewable Heating Hub is not in the business of dismissing technology wholesale, and biomass is not without a legitimate role. For the specific category of rural, off-grid properties currently heating on oil or LPG (where the alternatives are limited, where fuel costs are high and where access to heat pump installers is often poor) a well-designed, properly maintained biomass boiler can represent a meaningful reduction in both running costs and carbon emissions relative to what it replaces. Agricultural residues, sawmill waste and fast-growing energy crops come closest to genuine carbon neutrality, as their carbon cycle completes within one to several years, a wholly different proposition from whole trees sourced from managed forests.

The problem is that the UK's biomass policy does not meaningfully distinguish between these cases. The same renewable designation that covers a sawmill-waste pellet boiler serving a remote Scottish farmhouse also covers systems in homes that, by any reasonable analysis, would be better served by a heat pump. The grant exists. The MCS certification pathway exists. The marketing exists. The nuance sadly does not.

The Honest Assessment

Biomass heating has been sold to British consumers under a carbon neutrality claim that the science does not fully support on any timeline relevant to net zero. Studies indicate that even when wood displaces coal (the most favourable comparison) the excess carbon dioxide emitted is not fully reabsorbed by forest regrowth until well into the next century, with carbon debt payback times measured in decades to over a hundred years. We do not have decades. The net zero deadline is 2050. The Paris Agreement's most ambitious target demands action this decade.

None of this means every biomass installation is environmentally reckless. Fuel source, supply chain, forest management practices and what the system replaces all make an enormous difference. A locally sourced wood chip boiler replacing an oil-fired system in a well-insulated rural property is a fundamentally different proposition from a pellet boiler in a suburban home with gas access two streets away.

But that distinction requires homeowners to ask questions that the industry, the grant schemes and the certification frameworks do not always encourage them to ask. At Renewable Heating Hub, we think they should ask them anyway.

If you are considering a biomass boiler, demand to know where your fuel comes from, how its carbon accounting has been assessed and what maintenance regime is required to keep the system performing to specification. If you are in any doubt about whether your property genuinely suits biomass over a heat pump, get an independent assessment from an engineer with no financial interest in either answer.

Is the repair just a case of

more mastic or is there something missing from the design which might mean that this is a recurring problem?

The problem with this is clearly timescale, one person on the team commented that their typical lead time was 6 weeks, to which I responded, only slightly tongue in cheek, that the local plumber will fit a replacement boiler next week, and its not the local plumber that needs to change! 

One approach is to encourage people to be prepared, but this will be a niche only.  Using electric heaters temporarily is hardly attractive mid winter, both for comfort and cost reasons, so while that may work for some its another niche and we still aren't addressing the real issue, which is lead time.   That said I do think that its valid to start off with a particular segment (much as Octopus did) and build out from there.

So here are some observations which might point at how the lead time issue could be addressed:

• The Ofgem standard house consumes 11,500kWh gas per annum, this puts it at <6kW (actually closer to 4kW) loss at design temperature.  This suggests that a fairly high proportion of houses are <6kW
• Most manufacturers minimum capacity machine* has a nominal output of 5kW or more
• You generally want 5kW+ for DHW reheat anyway

• If radiators are 'undersized' its always possible to compensate by increasing the flow temperature, and R290 pumps can run at 70C
• Radiator upgrades are an easy 'stage 2' retrofit, in fact there is a good argument for measuring what actually happens before deciding which radiators to upgrade, because its a real measurement not a gigo spreadsheet.  Thats what Adia advocate and make the kit for!
• provided primaries in a <=6kW house are 22mm and there is no microbore, the plumbing is going to work (or, worst case, there are no further checks that would be done as part of a survey that will detect a reason why it wont work)
• Real world SCOP is dependent more on installation quality/operating mode than on FT - see graph below from openenergymonitor (I suspect that this is what is behind the zero disrupt heat geek offering and Octopus's philosophy!) 

So, taking all the above together I propose that the following is a technically practical way of dealing with the 'failed boiler' scenario, which crucially does not compromise quality so far as I can see.

• Do some very basic checks to be certain that the house loss is <=5kW, no microbore, 22mm primaries
• fit a 5/6kW heat pump and UVC plus th a 50l volumiser to ensure defrost works
• Fit Hhomely or Passiv, or if you want the full monty Adia, leave it to self adjust

Householder now warm, panic over!

Over next few months monitor flow temperature etc and then return in summer or a few weeks later to upgrade radiators if necessary.

This requires some derogation from MIS3005-D, but this is justifiable from an engineering standpoint.

Obviously, in addition to the technical viability, we have to consider if its commercially viable (or make it commercially viable).  I suspect that this might not be attractive for the 'top installers' who employ engineers that are expert in everything, but maybe its a very useful 'entry point'/training ground.  Do a dozen of these before you do anything else.  From a learning point of view I would think this would actually work better - instead of swallowing the whole elephant in on go you first get some understanding of the basics nd of commissioning in a relatively 'safe' context, and only once this is 'under your belt' do you need to learn the more detailed design stuff.  Maybe it should be a separate 'MCS light' qualification which can be upgraded to the full month later, targeted at your local plumber who normally fits boilers?

I would comment further that doing this this way poses no threat to most existing installers, this is a new market that many cant actually access at present.

Constructive comments invited - we have to solve the 'failed boiler' problem if heat pumps are ever to succeed in displacing fossil fuel burners, is this the basis of a start? 

*with the exception of firmware limited versions of higher capacity machines, the minimum output of which generally be the same as its larger cousin

I have recently purchased a very run down little bungalow and am in the process of renovating, I will be also be adding an extension on the rear. There is no gas feed to the property and the current heating system is a coal fired back boiler. I was hoping to take advantage of the £7500 grant scheme to replace with an air source heat pump (was thinking underfloor heating in the extension I will build and upgrade of the radiators in the existing property. However upon further investigation it appears a coal fired back boiler replacement is not covered by the grant scheme as only fossil fuels! I am confused as isn't coal/anthracite a fossil fuel?!

Is anybody able to confirm if I am correct and would not be able to get the grant please?

Our house has a 3.5kW ASHP and finally a working smart meter.  Our second vehicle is dying (K reg Golf) and won’t go past the MOT in September.  We live on an island so most of our driving is quite short distances.  An EV would make some sense.  We currently have no battery storage of any sort.  Ideally I would like to use a time of use tariff to charge the car and use that energy during the day to power the house - when the vehicle is not in use. Our house typically uses max 10 to 15kWhrs a day.  Is the concept of pursuing V2H a logical direction to go and should that influence our choice of EV if we buy one now - or should we wait a few more months or years?

Vito Energy have gone into liquidation, which is a shock for what seemed a viable company with Patrick Wheeler appearing on several RHH videos.

I had my heat pump installed by Vito Energy 2 years ago, and tried to book an annual service, all I got was an engaged tone. I checked with Company House, and they went into liquidation 6 days ago. Does anyone know anything more about this?