Frequently asked questions

about our domestic hot water products

Below are some of the most frequently asked questions about our domestic hot water products. 

The answers cover our third-generation UniQ and the latest generation Thermino.

Sunamp heat batteries can be fitted by a qualified plumber or electrician in accordance with the relevant instruction manual, where you will find also additional product information. Search our list to find an approved stockist and installer near you.

The Sunamp product warranty states that you must be a competent person to install a thermal battery. This means that we do not demand any specific training courses, however it is expected that you have the required qualifications, knowledge, training and experience to be able to understand the basic plumbing and electrics to install something like an unvented hot water cylinder. 

Our product manuals give clear installation guidance. You’ll find the installation manuals on each Thermino product page on this website. We also have instruction videos on our YouTube channel

Our Thermino heat batteries connect with mains electricity and many other heat sources, including heat pumps, solar PV and boilers. They are ideal space-saving replacements for traditional hot water cylinders.

As we are often asked this, Sunamp Thermino batteries do not connect to solar thermal units, pellet, oil or wood burning stoves, swimming pools or hot tubs.

Yes. Specific models in the Sunamp Thermino and UniQ battery ranges are compatible with heat pumps from Daikin, Samsung and Vaillant. 

We have tested the ability of the heat pumps from these manufacturers to meet the flow temperatures requirements of the heat battery (63-65 degrees Celsius).

The Thermino range comes in different sizes and configurations depending on the desired application. Please see the prices offered by Sunamp’s approved stockists and installers who can help you further.

Search the list to find one near you.

Running costs depend on many different factors unique to your home. 

For example, electricity tariff, energy usage, energy source, frequency of usage, ambient temperature versus indoor temperature and heat battery size.

Sunamp does not sell directly to homeowners. Our hot water products are available through our approved stockists who will be happy to help you. 

Any direct sales enquiries received from individuals are forwarded to our installer and distributor network. Search here to find an installer or stockist near you.

Yes. We recommend a Thermostatic Mixing Valve (TMV) since the hot water output of the heat battery is at 55 degrees Celsius and therefore, there is a high risk of scalding if a TMV is not fitted.

Thermino heat batteries use Plentigrade, a high-performance phase change material which is much more energy dense than water. This is similar to the material in a handwarmer, which stores heat and releases this as it changes from liquid to solid, but with some key differences.

In a handwarmer, the phase change is activated using a metal disc and once the reaction starts, it can’t be stopped. This means that all the material in the handwarmer will change phase and all the stored heat will be released. The reaction for the Plentigrade phase change is temperature activated and the material stops changing phase when you stop using hot water. The battery then only recharges the material which has discharged its heat to heat up the water.

In terms of the temperature of the water coming from the taps, a tempering valve mixes cold water from the mains and hot water from the heat battery to achieve the desired water temperature.

Yes. We recommend you use a water conditioner, such as a HS38, to keep limescale in the water to under 150 ppm. It can be used with any size heat battery.

Please refer to our product data sheets and installation manuals. 

You’ll find them on the Thermino and UniQ product pages on this website.

You can register any of our domestic hot water products – Thermino and UniQ – by visiting the warranty registration page

To get in touch with us, please email 

Please include all details of your enquiry and relevant product warranty information. We will respond to all enquiries in a clear and friendly manner within one working day.