Mixergy Reviews 

Had the tank for over 2 years. Very efficient but recently the tank wouldn't stay connected to the Internet. Called Customer Service and within 24 hours under the very clear guidance of Khizar I changed the connection directly through a Nano Router and immediately full connection returned. Very happy.

I love the control that my Mixergy tank gives in terms of scheduling and the option to heat from solar. The app is great. I've had to contact support to reset a tripped thermostat on return from holidays. Instructions were clear and response was prompt. Absoluted delighted with my Mixergy. :-)

Support is where this goes wrong. We had an original issue during installation that left us without hot water. Mixergy took days to progress the issue arguing between themselves and the builder. It was only when escalated to CEO did the issue get fixed.

Roll on 18 months and the controller has completely died. Day 1 issue discovered after 5pm - no way to raise an urgent ticket. Day 2 ticket raised in morning and told high priority due to no hot water and response guaranteed within 24 hours. 24 hours later and no response. Called again to be told they hope someone will respond before the end of the day, they cannot confirm queues that the engineering team have to get through or give any actual SLA, they cannot connect directly and all they can do is escalate a ticket that has seemingly not been interacted within in the previous 24 hours.

The real problem is that we can't get someone to just come and fix it either this or last time. In both cases the boiler is fine, plumbing is fine but it's a tech issue. Your only choice then is Mixergy. If this was a Sky box I'd be frustrated without service for a few days - but when it's hot water provision in a house its critical infrastructure and not given the appropriate SLAs or priority.

As a customer the only option I have to resolve this without Mixergy in the loop is to pull the tank out and switch to a dumb tank or to incur costs to arrange for family to shower somewhere.

We pay the monthly monitoring fee which is listed as optional but required to support the warranty unless you arrange annual independent service of the tank (again no standard plumbers here and all quotes for that were more than the annual monitoring fee). So despite the assurances on other comments that it is optional - it's optional in name only if you want warranty support.

When the product works it is fine - we're in Scotland with reasonably low water use and high electricity usage as a household so we don't particularly benefit from solar divert and a combi-boiler would cost us less factoring in the monthly fees.

The problem is that Mixergy do not feel equipped to actual respond to any urgent issue when it comes up. A lack of hot water in a system designed to do just that one thing should be able to be escalated urgently and have appointments booked at the same time. So it's either lack of investment in service and aftercare or that so many people using Mixergy have broken systems at once they're unable to support it.

I have waited since April for Mixergy to fix my boiler system which will not connect to the internet so I have absolutely no control over my hot water. They promised a video call to reset the system but this did not happen, they then booked an engineer visit who didn’t turn up, I emailed them five times in one day no reply. Today an engineer arrived at the last appointment so I am now a full day of not working working and I am self employed and as I warned Mixergy this engineer would not be able to help as it is a software problem not a boiler heating issue he was unable to do anything. I am still unable to control my system. Mixergy are a dreadful company and I have no idea what to do as they just don’t reply, they only have two technicians to speak to so the phone is never answered.

Avoid avoid avoid.

Very fast and efficient. Worked out a problem several engineers could not fix. Excellent service.

Having sold us two clinders (400L and 300L) with their integrated Solar Diverter as being ideallly suited for an off-grid installation, it then turns out they have no instructions for how to actually get their Solar Diverter to work with an off grid system.
The included clamp is intended to be fitted to the line coming from the grid supply to enable automated switching. Great if you are on the grid, not so useful if you are not.
We have two off grid properties, both running PV panels and Victron (pretty common and well established) system to charge two 300Ah Fogstar Pro batteries. Nothing unusual, but a week after asking, Mixergy still unable to give any guidance on the electrical installation. We will return to the UK tomorrow with the system still not functional. Perhaps I'm expecting too much, but if sold as a sytem well suited to off-grid, ideally there would be instuctions supplied as standard, but at the very least perhaps there should be some knowledge within the company on how to do that. So far, nothing, just a "we have passed it on to technical" etc.

Update following Mixergy's response:
Thanks for your response. We have now heard from your technical team, who have effectively confirmed that there is no way to make the integrated Mixergy Solar Diverters operate as intended in our off-grid installations.
What is particularly disappointing is that we specifically told Mixergy that the properties were off-grid, and specifically asked Mixergy to confirm that we had the right cylinders.
In our very first email to Mixergy Enquiries, on 19 March 2026, the opening sentence said:
“I have two jobs I am working on in France where I have specified your cylinders. Both properties are off grid in the Southern Alps.”
Then, in our second email the same day, we explicitly asked:
“Perhaps you can confirm that we have the right cylinder for our two jobs.
We need a direct (unvented) 300 litre cylinder for a house that is completely off grid. It has a 5 kWh array which feeds a 5000 watt inverter with a large battery bank.”
We feel those messages made it abundantly clear, before the cylinders were supplied, that they were for off-grid properties. At no point did anyone at Mixergy raise the fundamental issue that the integrated Solar Diverters rely on a grid connection and therefore cannot operate as intended off-grid.
Instead, two cylinders were shipped halfway across Europe at considerable expense, only for us to discover that the solar diversion system cannot work as required.
Mixergy now says that installers should check the documentation before specifying the cylinders. But in this case, we did exactly what we would reasonably expect a customer to do: we explained the installation and then asked the manufacturer to confirm that we had the right product.
You know your system; we are learning about it. Surely, when a customer specifically describes an off-grid installation and asks whether they have the correct product, it is reasonable to expect the manufacturer to identify a fundamental incompatibility such as requiring a grid connection.
The cylinders themselves may be perfectly good products, but our experience of Mixergy's advice and technical support has been extremely disappointing. The problem therefore remains unresolved. We have two expensive cylinders with integrated Solar Diverters which Mixergy has now confirmed cannot operate as intended in the off-grid installations for which we specifically told them they were being purchased.

We have had this tank for 4 years and it has always had problems. A - Initially when installed it had wrong parts and the installer had to organise replacements parts.
B - After installation our excess PV was not being used and this was down to incorrect wiring. C- The company tried to get me tied to an annual maintenance contract which is not required for a open system. D- the tank continually loses connection and has to be reset wasting time. This happens 2/3 times per month. E- the app is illogical in places e.g. turning off PV usage means reseting two flags. Also when boosting ( to say 10 %) it boosts to the current temperature at 10 % not a desired temperature.

If only I had known....

I installed a 150ltr cylinder in our three bedroom house in Bristol 5 years ago. The water is heated from the storage battery which in turn is topped up from the solar panels and off peak electricity. We had no problem with the installation although there was an initial glitch with connecting to the WiFi which was due to the location in the garage and was soon rectified. In retrospect, a smaller cylinder would have been sufficient for our needs. We also installed a heat pump three years ago and had the gas supply disconnected. I couldn’t be happier with our choices and wish Mixergy every success.

Mixergy cylinder was sold to me that it will save energy and very efficient .But after one year use i have found that actually my gas bill has gone up .Itself this system is very costly plus no local engineer or even British gas engineers they were able yo help me twice when system stopped working .So inaddition to boiler care plan from British gas I have to buy Mixergy plan which cost 89 pounds .And if cylinder stop working or any other problem happen on Thursday night or Friday morning ,things would not be sorted till Monday afternoon.I had this issue a month after installation where after spending so much money I have to call many times to sort out the issue and very first year in the first month I had to buy care plan as British gas engineers who installed the cylinder had no clue what to do and mixergy engineers were off for weekend and I was e out hot water .

logged a call 7 days ago for my system that isnt working. still not had a reponse from the tech team despite chasing twice. just not good enough.

We moved into a new property which has a new technology for hot water system but didn’t work and we had no hot water for some time. Someone was sent to come sort it and after hours of working on it still nothing. However Mixergy sent someone else (Abbas) he came late and fixed it. He was very kind and patient to explain how the hot water system works and also sent a follow up instructions. A good customer service!

We are incredibly grateful to the engineer Abbas Khan for the exceptional service provided. Our solar power system had been out of operation for a long time, and after struggling to find a solution, it was finally fixed quickly and efficiently.

Not only was the engineer highly skilled and professional, but also incredibly friendly, patient, and willing to explain everything clearly. Every question we had was answered with care, giving us complete confidence throughout the entire process.

It's rare to come across someone who combines technical expertise with such outstanding customer service. Thanks to the engineer's dedication and efficiency, our solar system is working perfectly again.

Thank you so much for your hard work and excellent support. We couldn't be happier with the service and would highly recommend you to anyone looking for a trustworthy and knowledgeable solar engineer!

Good and bad
I’ll start with the bad.

- top up pump failed after 4 months
- tried 4 times on a phone call over 2 days and went to voicemail
- Initial customer care support line is terrible. (New build plumber called them, a guy answered the phone and said he can schedule in a plumber but can take up to 2 weeks. I explained I have no hot water and a 10 weeks old baby, I need a better confirmation on a repair date. Asked him to call keep me on the line and speak to the department that arranging bookings. His attitude was poor and could not care less, didn’t even bother attempting to assist or understand the situation.)
- a slight design improvement required. The pump needs a shut off valve instead of draining 210L in order to change it and requiring it to be topped up again. It’s a very energy efficient self sustaining immersion heater but that section doesn’t seem like it was thought through and very green in saving water.

Good
- Christine or Christina (not sure of her name) called me and was very helpful and accommodating. Very easy to talk to and a friendly approach.
- Rob was then speaking to me in explaining how the system works, talked me through how to use the fail safe back up system. (Even those that failed but no fault of Mixergy)
- Dan turned up early next day and fixed the issue.

In summary, once the case is escalated or in the right hands. The customer service is great.

Rob and Dan both have very deep knowledge of how the system works. They are very patience and willing to give time to explain and answer any questions. Rob even video called to assist in correcting the mistakes the new build developers made/installed incorrectly.
It’s so nice to have extremely competent staff members to assist.
Rob even messaged me the next day after the appointment to check up if everything was repaired and working normally which is so rare now a days. Overall the service has been fantastic.

I recently bought a house in Kellen homes, Hawks View. The property comes with the Mixergy boiler. I had trouble connecting the boiler to my phone. Abbas from Mixergy who was working in the neighbourhood immediately responded and sorted the issue. Great work.

I did have problems getting Mixergy to come to my development to solve an issue with my hot water tanks , but they have now sent a very experienced engineer who has found the problem and it appears to have been resolved and the customer is very happy which was the main thing to achieve , Thank you again David

Mixergy Technical Support are very professional. My Tank went off-line and they recommended a nano router and got me back on-line. Thanks to Khizar.

Abbas khan was very helpful in resolving my issues at plot 83 Calder Rise, David Wilson Development in Preston. He was patient and friendly, keen about customer's satisfaction. Excellent customer service

The Mixergy cylinder came pre-installed in our new-build home, so this was not a product we chose.

Despite being marketed as energy efficient, our gas bill tripled within the first month. The system consumes an unreasonable amount of energy and performs nothing like what is advertised. This is completely unacceptable for a modern, supposedly efficient setup.

Customer service has been consistently unhelpful. They do not answer the questions you ask and instead respond with generic, evasive replies that do nothing to resolve the issue.

Technical support has been even worse. Their responses give the clear impression they do not want to help, and on at least one occasion remote changes were made to the system without our consent or proper explanation. This is extremely concerning and has destroyed any trust we had in the product or company.

Overall, a very poor experience. High running costs, misleading efficiency claims, and unacceptable support. Would not recommend under any circumstances.

I purchased a direct heating cylinder which I heat using off-peak electricity at night. The cylinder works well and I like the functionality of the app. However, I'm not impressed with the company's customer support service. Most cylinders are now installed as unvented pressurised systems, but we needed to install ours vented with a cold water tank in the attic. There were no specific installation instructions for this installation method and we had a question about whether a tun dish was required. My plumber phoned the installation help line and was promised a call-back which never came. Initially the tank would not operate and it took a little while to understand that a system reset was needed. Finally, for the first 24 hours, the data in the app suggested that the tank was turning on and off at a high frequency which seemed very bizarre. A screen grab of the recorded dats was sent to Mixergy support and an automated reply said that the support team would be in contact soon. It's now a month on and I've heard nothing. However, the strange data has not reoccurred and the tank is working fine. So a mixed review for Mixergy!

My ancient hot water tank developed a leak that could not be repaired. Our household hot water usage is unpredictable and having a full tank of hot water 24*7 was costing a lot of money. Our gas water heater was also basic, with no intelligence. Looking around, Mixergy seemed to the answer.

In practice, it is even better than I had realised. On many days, we heat only 15% of our tank because that's how much we need. When my son returned home for a while, we simply increased to 25%. When we have a houseful, we will heat to 80%. It's all so efficient and easy to control. It works as promised. Everyhome would benefit from Mixergy.