Mixergy Tank Failure

bontwoody · 2025-09-13T05:40:14Z

Hi. I had my Mixergy tank fitted nearly three years ago and on the whole I've been very happy with it. A week or two ago we noticed a small leak on the floor beneath the piping. Initially I thought it was a leakage compression joint which I nipped up. This week I was woken by the sound of water and saw that the tank was discharging water via the tundish when heating. The most likely reason seemed to be a low charge in the expansion vessel, so I removed this and checked it. It was at 50psi. I've contacted mixergy and they suggested I reduce this to 2.5 bar and monitor the situation. It was at this point I noticed that the side of the tank seemed bulged out. When I had the tank installed the plumber pointed out to me a slight bulge in the outer case which I put down to over zealous insulating foam insertion at the time. I recontacted Mixergy and they told me to stop using the tank and they would replace it under warranty. That was Wednesday and I have heard nothing since. What I would like to know is what might have caused the problem and if it lies with the tank or the installation by the G3 plumber or the failure of a part, presumably either a valve or the expansion vessel which seems fine. Images attached. Any comments welcome. Thanks

Page 5 / 5 Prev

Domestic Hot Water & Cylinders

Last Post by Mixergy 3 hours ago

50 Posts

8 Users

21 Reactions

1,288 Views

RSS

bontwoody

(@bontwoody)

Noble Member Contributor

Joined: 4 years ago

Posts: 891

Topic starter 10/10/2025 12:31 pm

@editor Ive just emailed the CEO, Mars, so lets see what happens.

House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60

ReplyQuote

Mixergy

(@mixergy)

New Member Member

Joined: 4 weeks ago

Posts: 2

10/10/2025 2:14 pm

Thanks for raising this. We’re really sorry we haven’t been active in this thread, our priority has been to work directly with the customer and our technical team to get this resolved as quickly as possible.

This issue remains a top priority for us. Our engineers are continuing to investigate and implement a fix, and we’re working closely with our service partners at Robert Heath to make sure it’s resolved as soon as possible.

We know how frustrating this has been and genuinely appreciate your patience while we get it sorted.

ReplyQuote

Page 5 / 5 Prev