Example 30th Apr:
- Was working fine until about 1pm.
- Probably reset every 3 or 4 mins so solar production highly impacted.
- Batteries were full
- I disconnected EV to prevent any IOG control.
This started around 12.30pm that day and was particularly bad for 2 hours. After that the reset was less frequent but still happened.

I have been using WonderWatt with IOG for more than a year. With no noticeable issues.
No recent changes but still wondered if somehow GivEnergy/IOG/WonderWatt are having conflict?

I've continued to investigate... with help ChatGPT as well.
It seems the most likely reason is Grid overvoltage
Probably happens most with:
- high exports
- sunny day
- Full battery
But not exclusively. Also happening today when production low (cloudy) and battery not full

I will try and keep some capacity free in my battery as one test.

Afaik Gen1 Hy5.0 has a max voltage of 253v before tripping? (DNO 230v +10%).
My logs on first review show regular 256 -260v
I contacted DNO to see if they can be persuaded to show some interest.
Just wondered if any other suggestions to help diagnose or cure?

EDIT: Sent info to DNO. Incredibly engineer sent within 3 hours.
- ran initial tests
- fitted a voltage monitor to run for 3 days with solar panels off
- he is also arranging for line & pole checks for connections as well as potential swapping of phases (apparently one phase tends to run higher than other)

amazing level of interest & speed of service!

He will remove monitor after 1 week and I will update with news

Edit2

I believe this problem may have been happening intermittently for a very long time. But only recently paid attention to it!

Earlier this year, we wanted to have some fun. We built a survey. We called it a persona exercise. We asked 80 heat pump owners to be really, really honest. And what came back confounds just about every assumption the industry likes to make about the people who've already taken the plunge.

This is not a portrait of the green zealot. It is not the tech bro with a spreadsheet obsession. It is not the retiree guilted into action by a David Attenborough documentary. The British heat pump owner, at least based on who reads and participates at Renewable Heating Hub, is considerably more interesting and considerably more complicated than any of those caricatures.

Here is what 80 respondents told us.

Older, Detached and Done With Gas

Let's start with the demographics because they tell an interesting story. Nearly six in ten respondents are aged 50 or over. A quarter are in their forties. Fewer than one in ten are under 40.

This technology is not being adopted by the young. It is being adopted by people who have owned homes long enough to have had a boiler fail on them at Christmas, watched their gas bills climb for a decade and concluded that enough is enough. They have the capital, the stability and the patience that heat pump ownership still demands.

Two thirds live in detached properties. This tracks practically, but it also points to a persistent equity gap that nobody in government or industry seems particularly bothered about. The technology is being normalised among the group of homeowners least representative of the overall housing stock.

The Money vs. Planet Debate? It's Complicated!

Ask anyone selling heat pumps what drives buyers and they will tell you it is saving the planet. The data has a different answer... or rather, several answers at once.

Carbon reduction was cited as a primary motivation by 49% of respondents. Amazing. But grant availability came in second at 41%, ahead of lower running costs (29%), early adopter curiosity (22%) and new build or renovation timing (19%). Nobody is being guilted into this. They are being incentivised.

When we pushed people to be even more honest (which mattered more at the start, really?) 32% said monthly bills. Twenty-eight per cent said environmental impact. Eighteen per cent said comfort and consistency.

That is a more complicated picture than the industry's marketing would have you believe, and it has real implications. If the Boiler Upgrade Scheme disappeared tomorrow, what happens to those 41% for whom the grant was decisive? The demand is partly policy-created. That is not a criticism... it is just true, and it should be considered for forecasting what happens next.

They Don't Talk About Saving the Planet. They Talk About Being Warm.

Here is the finding that should be pinned to the wall of every heat pump manufacturer's marketing department.

We asked respondents how they actually describe their heat pump to friends and family. The most common answer, at 39%, was: "the house is way more comfortable." Only 16% lead with cost savings. Twelve per cent go with long-term sense. Just 12% open with the environment.

The technology appears to have over-delivered on comfort and under-delivered (or at least failed to lead) on bills. And once someone has lived with a heat pump through a full winter, comfort becomes the most natural way in to the conversation. The consistent temperatures. The warmth that does not blast and then die. The end of that cold snap between the boiler firing and the radiators finally doing something useful.

Sixty-two per cent say they feel keen to explain their heat pump when asked. A further 25% are happy to recommend it. That is an enormous pool of unprompted advocacy sitting in the existing owner base, and most of it is going to waste because nobody in the industry has a systematic way of activating it. Word of mouth is the most powerful marketing channel available, and it is essentially being left to run on its own.

The Energy Nerd Factor

Yes, the survey is self-selecting. Our respondents found it through Renewable Heating Hub, which means we are sampling the engaged and the curious rather than the random homeowner who ended up with a heat pump because their installer sold it hard. We know that. But even accounting for it, the level of energy literacy here is quite something.

Ninety per cent know their electricity tariff type and have switched more than once. Fifty-six per cent think constantly (their word, not ours) about tariff timing and load shifting. Of those on time-of-use tariffs, 86% are actively moving heating, hot water and appliances around to chase off-peak rates.

Seventy-four per cent already have solar PV. Sixty-two per cent see home batteries as an essential piece of the puzzle rather than a nice-to-have. Half already own an EV. These people are not waiting for the smart energy future. They have largely self-assembled it on their driveways and rooftops already.

They Don't Quit When It Gets Hard

We asked what respondents would do if electricity prices doubled tomorrow. The single most common answer, at 39%, was "be annoyed, but ride it out." A further 30% said they would still back the decision because it is the future. Eighteen per cent said they would immediately look at more solar and battery. Just 12% said they would seriously question the switch.

One person said they would pretend not to look at the bills. Relatable.

When new technology does not perform as promised, 46% say they feel determined to optimise it. Forty-one per cent say they are annoyed but pragmatic. Only 6% get angry at the industry. These are not people who will be scared back to gas by a difficult first winter or a confusing controller.

And when a professional gives advice that does not quite make sense to them? Half research it independently. The other half challenge the professional directly and ask questions. Not one respondent said they just accept what they are told.

The age of the nodding homeowner who signs the contract and hopes for the best is over. If installers have not noticed that shift, they will keep generating the complaints we document in the Renewable Heating Hub Consumer Intelligence Index. The customer is better informed than the industry realises, and in many cases better informed than the installer standing in their hallway.

The Install Story Has Gaps in It

On the whole, install experiences were positive. Forty-four per cent rated theirs as excellent and 29% as good. But 12% called it mixed, 9% said poor, and one respondent, admirably to-the-point, said "disaster." Five per cent had something still unresolved at the time of completing the survey.

More telling: 68% say their understanding of heating has increased massively since installation. That is impressive on the surface, but look at it differently and it is an indictment of the commissioning process. The learning is happening through forums, YouTube and months of trial and error... not through the handover. People are educating themselves after the fact because the industry has not yet worked out how to educate them during it.

Installers were the biggest single influence on purchase decisions, at 25%. Online forums, including Renewable Heating Hub, came in at 22%, level with government grant information. YouTube influenced 15% of decisions. Manufacturer marketing influenced just 2%.

One Word: Sensible

We asked respondents to describe in a single word how their heat pump makes them feel. Fifty-five per cent chose "sensible." Twenty-one per cent said "proud." Nine per cent said (and we appreciate the honesty) "smug." Six per cent said "disappointed."

That 55% figure is the most important number in the entire survey. Not the EV ownership rate, not the tariff switching rate... this. Because "sensible" is not a word anyone in heat pump marketing uses. Sensible does not make it onto manufacturer landing pages. Nobody is running a campaign around "this was just the rational thing to do."

But it is exactly what most of these owners feel. They researched it. They weighed it up. They made a decision they consider sound. They are not evangelical about it. They are not smug about it... mostly. They just think they did the right thing and they would quite like the rest of the world to catch up.

The archetype that emerges from all of this is less a type and more a specific person: over 50, detached house, done the research, on a time-of-use tariff, solar on the roof, probably an EV in the drive, thinking constantly about energy use, perfectly willing to push back on a questionable installer recommendation, and living in the most comfortable home they have ever had.

The industry has not quite worked out how to talk to that person yet. Which is a shame, because there are a lot of them, and they are very happy to talk back.

As of a week or so ago, it seems the VW/Audi group decided to block access to the API their app uses unless it's accessed by an application whose developers have paid for the privilege. That means the VW Connect integration for Home Assistant and any other similar bits of software can no longer authenticate. Very cynical, mercenary and high-handed of VW/Audi, it also appears to be making significant noise on mainland Europe with a lot of people in questioning whether it may contravene the European Data Act.

Not a lot anyone here can do in the short term, but if intelligent integration of an electric vehicle into your wider smart home is any kind of priority for you and you're looking to purchase an EV to do so, I would suggest you avoid a Volkswagen, Audi, Seat, Cupra or Skoda.

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.