Climastar vs Fischer Future Heat breaks down the key differences between 2 of the UK's leading electric heating providers.

The UK has many different heating solutions. Traditionally, gas and oil fuelled boilers were viewed as the solution to our problems. That is no longer the case. From 2025, no gas heating installations will be allowed in new domestic and commercial properties across the UK – so what is the solution?

Perhaps the solution lies in using electricity to power your heating.

Who, therefore, can provide the UK homeowner with a viable electrical heating solution? When it comes to electric heating, we have looked at two main players; Fischer Future Heat and the Harmony range by Climastar. We compared the effectiveness of their overall offering to help consumers decide which is a better solution for them

A Harmony Heater by Climastar
A Heater from Fischer Future Heat

Providing the room has been correctly measured, and an accurate heat loss survey has been carried out, both Fischer and Harmony brand radiators will heat your home.

However, these two systems work quite differently. We want to find out if a Clay Core Heater such as Fischer is superior to a Silicon Heat Battery such as the Harmony Range heater.

Fischer technology is tried and tested over many years. It is effective in heating a home, but it’s old technology. The new technology has moved away from heating clay core or clay bricks commonly used in Night Storage Heaters. Newer technologies are using sophisticated smart controllers and electronics to heat the room faster, and more efficiently.

This begs the question of what is better; new or old?

Guarantees & Warranty

Fischer Heating vs Climastar

Both companies offer a 10-year parts and labour warranty, so there is no difference there. However, what has been noted in our research is that Fischer will charge the customer a £250.00 service charge before coming out to repair the product. The customer must pay the service charge in advance of the visit. 

Any work carried out during the visit to rectify the fault is not charged and parts are included. In our opinion, it’s difficult to see how Fischer can claim a 10-year warranty on labour and parts without highlighting the £250.00 service charge. If a product fails within a warranty period, we think the product should be repaired with no cost to the customer. 

From our experience, Fischer radiators are certainly reliable, however, if the consumer experiences four separate failures over this 10-year period, they will be paying £1,000.00 in service charges to rectify the faults, so that is a negative against Fischer. 

The Harmony range manufactured by Climastar issues a 10-year warranty on parts and labour with zero call-out charge. This means if anything should go wrong, the consumer is covered for the next 10 years, resulting in total peace of mind. 

Best Buy on warranty: The Harmony range by Climastar


Heating is about keeping our homes warm, but we want all fixtures and furniture to look great too. The look and feel of a product is extremely important to most consumers, so what heating system wins on looks?

Fischer Heaters:

Fischer heaters are encased in a fluted mild steel frame. The standard colour is RAL 9010, however, Fischer heaters can be ordered in any colour at an additional cost. Changing from the standard heater colour to any other RAL colour is chargeable by around £200.00 per heater.  That starts to be expensive if the consumer is ordering several heaters.  

Even changing from the standard off white heater colour to a brilliant white is chargeable by around £200.00 per heater. 

Fischer heaters look very similar to a traditional radiator you would find in a home powered by a gas or oil boiler.  The depth of the radiator is 110mm but the bracket to hang the radiators on the wall adds a further 20mm, therefore the front of the radiator sits approx. 130mm from the wall.

Fischer radiators come in a range of different widths and heights.  Like all mild steel radiators, care needs to be taken when working around them as it is possible to indent the heater if hit hard with household items such as vacuum cleaners or carpet cleaners, which can be easy to do when trying to clean underneath the heater.  

If you are using a mild steel radiator of any kind in a wet environment (bathroom or shower room), there is a high probability of rust or discoloration at the bottom of the radiator. This happens once the radiator has been exposed to water or condensation for an extended period. Of course, this is a typical drawback with all mild steel radiators, not just Fischer. 

As the Fischer radiator is warranted for 10 years, the question is: will a mild steel radiator in a damp environment retain its sheen after such a time? If the consumer takes care and dries them off after using baths or showers, they will look fine, but are consumers going to do that after every visit to the shower? 

Fischer bathroom heaters have an IXP rating of 4 (IXP4), meaning it is protected from splashing water, whereas the Climastar Harmony range of bathroom heaters carry a rating of IXP24, protecting them from water spray from any direction. 

Therefore, the electrical protection is significantly higher when using a Harmony heater as compared to Fischer. It really depends on the environment you are using the heater in but on the ratings front the Harmony Heater does offer better protection.


The Climastar Harmony Range:

The Harmony range is manufactured to look like natural stone. The exposed front panel is manufactured using Silicon and Aluminium, with the finished material called Magma Stone. 

The Magma Stone carries a lifetime warranty. Manufacturers claim Magma Stone will never mark, lose its colour, lose its ability to transfer heat or alter in appearance in any way, and if it does so, they will replace it without question. That is a very strong guarantee. This means if the Magma Stone discolours, chips, cracks, or changes appearance in any way, it will be replaced. 

There are 6 different Harmony finishes:

 – Dark Etna – White Etna

 – Cashmere White

 – Light Grey Teide

 – Dark Grey Teide

 – Terra Limestone

We liked the look of these heaters as they do not resemble anything we have seen before. Depending on your preference, we believe these finishes will create a lot of interest for anyone considering updating the look and feel of a property. They are the nicest looking heaters we have come across. 

The Harmony range can also be manufactured as a curved heater, taking up minimal wall space. This allows the customer to install a heater in a relatively small space while still providing warmth for a large area. 

For example, if you had a room totalling around 40 cubic meters, (the common size of a standard lounge), you would require 2kw of heat to warm the room. To deliver that capacity, you would require a Fischer heater taking up 1.2meters of wall space, whereas a curved heater from the Harmony range would only utilise half that area (600mm), leaving significantly more room to place furniture. 

Looking at images of both products, our opinion is the Harmony range is more aesthetically pleasing and looks more interesting. As it comes in a range of 6 finishes, with no price supplement on any finish, the Harmony range is going to look more appealing on any wall in your home – unless of course you do want an off-white mild steel radiator which looks like a traditional central heating radiator! 

Best Buy on aesthetics: The Harmony range by Climastar

How the heaters work

Fischer Heaters:

Although these are both electric radiators, they work very differently. 

Fischer heat the room using a 40mm clay core, which Fischer call Chamotte Clay. Chamotte clay is an amalgam of fireclay, aluminium, and various agglutin’s which bind the materials together. The Chamotte is then crossed with a serious of tunnels which go through the centre of the chamotte clay and a continuous nichrome element is weaved throughout. 

Due to its low manufacturing cost, strength, stability at high temperatures, and resistance to the flow of electrons, nichrome is widely used in electric heating elements. Appliances such as hair dryers and heat guns are the most common. Typically, nichrome is wound in coils to a certain electrical resistance, and when current is passed through it, the Joule heating warms.

The Chamotte clay core then picks up the heat produced by the Nichrome element and stores it in the core. The heat is then passed into the room to keep the user warm. 

Contrary to what many think, Fischer are not like night storage heaters.  Night Storage Heaters work by warming bricks during the night and omitting heat for 9 or 10 hours the next day. 

Fischer heaters only hold heat in the core for a short period of time before needing to draw more energy to keep the room at the same temperature, so, the Fischer heater is not a storage heater in the traditional sense

When the Fischer thermostat calls for heat, the Fischer heater will draw the full heating capacity of the radiator. For example, if the heater is 2kw, it will draw 2kw from the customers electricity meter. There is no modulation of the flow of energy, so the Fischer heater is either on or off. This is not an unusual way of heating and can be found in different types of heaters from simple oil filled heaters costing £100.00 up to Fischer heaters which cost significantly more.

The Climastar Harmony Range:

The Harmony heater uses 2 x Silicon Heat Batteries to turn energy into heat. 

It should be remembered that whilst Fischer heaters work well to heat rooms, the Harmony range is a more modern heating system when compared to Fischer. Fischer have been manufacturing almost the same heater for the last 20 plus years. Whilst the Thermostats and receivers and some electrical components have been updated, the actual core and the method of delivering heat dates back to the 1990’s. 

While they are effective, they’re not what would be considered state of the art. 

The Harmony heater delivers heat using two Silicon panels, described as Silicon Heat Batteries. One of the heat batteries is concealed inside the heater casing and is placed at the back of the heater. The other panel is the exposed panel that is the front of the radiator. This creates a decorative effect. 

Both panels are approximately 9mm in depth so there is 18mm of core. This is less than half the size of the Fischer core, however, the Harmony heater does not rely on drawing large amounts of energy into a storage core. These use a TRIAC to control the energy flow to the Heat Batteries, keeping them topped up with energy which is converted into heat and dispersed into the room. Once the room is at the selected temperature, the TRIAC allows the heater to trickle-charge the heat batteries, reducing the amount of energy required to maintain the room temperature. 

What has impressed us about the Harmony range was that TRIAC-controlled electrical flow provides a variable heat radiator, which changes and controls the flow of energy akin to a dimmer on a light switch. The flow of power going into the heater is automatically increased or decreased as required, so the heater can use less power when the room is at temperature or draw more power when the heater needs to increase the heat level in the room. This is done automatically; no manual intervention is required to maintain the room temperature once it has been pre-selected. We are not aware of any other heating system that uses a TRIAC to monitor the flow of power. 

Therefore, the Harmony heating system is delivering heat in a very controlled and uniformed way compared to heaters such as Fischer, drawing the full capacity of the heater.

Both systems will heat your room and we can’t say which system is more effective in delivering heat, but we would consider that technology has generally moved on over the last 20 years and the Harmony range may be a better way of delivering a more consistent and accurate heating experience. 

Best Buy on operation: The Harmony range by Climastar

Thermostatic Controllers

Both Fischer and Climastar’s Harmony range use wireless controllers, allowing the user to set the time of day temperature and if required,  background temperature.

Both companies recommend these controllers are fitted to the wall opposite from the heater. This allows the controllers to measure the room temperature and not the temperature of the heater, giving the customer a better heating experience. What we found interesting is that the thermostats have a difference in accuracy. 

The Fischer system has a thermostat accurate to plus or minus 2°c. 

The Harmony system has an accuracy of 0.05°c.

Fischer Heaters: 

Fischer heaters store small amounts of heat and when the room reaches temperature, they stop drawing power and use the heat stored in the core to heat the room. If the thermostat was accurate, every time the room dropped in temperature by even 0.5°c the Fischer heater would start to draw power again and that would be uneconomical. The Fischer heater therefore has a plus or minus 2°c tolerance, so when the thermostat reads let’s say 20°c, the room may be slightly warmer or colder than 20°c and this allows for the tolerance of the thermostat. It’s not a fault; it’s how the system is designed to operate.

The Climastar Harmony Range: 

The Harmony Range uses a TRIAC to control the flow of power and therefore heat. The Harmony thermostat needs to be as accurate as possible to draw the minimal amount of energy to heat the room. We are informed that a 1°c increase in the thermostat can mean as much as a 10% increase in energy usage. Therefore, in theory, the more accurate the thermostat, the less power it will encourage the radiator to draw. 

An added advantage of the Harmony heater is the system can be controlled using Wi-Fi. This means you can control all the heating in the house via your mobile phone, laptop or iPad. You do not need to touch the thermostat to set the time or turn your heating on or off or select the temperature. It was surprisingly simple to set the parameters using the app (available on both Apple App Store and Google Play). The Harmony range is also compatible with Alexa or Google Home so you can control your heating via voice. It’s as simple as saying “Alexa, tun on my bedroom heating to 20°c” and the heating is on. The consumer can also monitor energy usage in real time. 

Another advantage of the Harmony Wi-Fi is being able to control the heating when you are away from the house itself. If the user is arriving home early before their heating is programmed to switch on, they can control the heating through their phone. Gone are the days you need to arrive home to a cold house. 

Also, if the homeowner is delayed in getting home, rather than heat an empty house, they can switch off or delay the heating coming on, so it can save the homeowner money. 

From what we understand, Fischer can supply Wi-Fi controls and a Wi-Fi hub to do a similar operation, but this is at an additional cost of circa £200.00 for the Hub and an additional £100.00 per controller, and you require one controller for every room. That makes it quite pricy compared to the Harmony Wi-Fi Range which includes Wi-Fi as an integral part of the heating system.

 Our clocks change twice a year and the Fischer Thermostat does not respond to time changes automatically, so you need to manually reset the clock on every thermostat in the Spring and again in the Autumn. Failure to do so means your heating comes on at the wrong time. The Harmony WIFI system has a British Summer Time auto reset, so when the clocks move forward or back, your heating requires no manual intervention. We were surprised Fischer did not have this built into the system and this is maybe something they should look at. No one want to spend time twice every year changing all the settings on their thermostatic controllers.  

As far as ease of set up is considered, there is not much difference if the Thermostatic Controllers are used manually. However, when you have the ability to set the system up via Wi-Fi, and the automatic clock change, the Harmony Range by Climastar UK is far easier.

Best Buy on Thermostatic Control: The Harmony range by Climastar

Open Window Technology

An interesting feature on the Harmony Range is Open Window Technology. 

Both Harmony and Fischer are Thermostatically activated heaters. A Thermostatic heater responds to temperature, so if the temperature drops below the desired level, the heater will switch on. If, for example, a consumer has either of these systems installed in their home and decides to open a window for fresh air, the temperature will drop to the outside temperature quite quickly. The same could happen if you are in a bathroom and choose to open a window to release steam and condensation. 

In such cases, a thermostatically controlled heater will switch on and try and heat the room. However, because the window is open, the room can’t store heat, so the heater is burning energy needlessly. 

The Harmony heater is quite clever and has a sensor that can detect the temperature drop due to an open window or open door and will switch itself off. Once the window or external door is closed, and the room temperature stabilises, the Harmony heater will automatically switch on and the room will begin to reheat. This means energy is saved and potential damage to the heater is avoided. 

It was disappointing that Fischer could not provide this safeguard, and again is something they may wish to look at.

Best Buy on operation: The Harmony range by Climastar

Performance Guarantees

Interestingly, both companies offer a performance guarantee. This states that if the heater fails to reach a temperature of 21°c when the external temperature is as low as -1°c, they will remove the heater and refund the customer. 

This gives the customer great peace of mind knowing the heaters will do what they say on the tin – adequately heat the room. However, Fischer only allows the consumer to test that heat guarantee for 4 weeks within the Heating Season.  Is that sufficient for a consumer to assess the effectiveness of the heating system?  

The Harmony Range allow the consumer 12 months from the date of purchase to call on the protection of the heat guarantee. 

The Harmony heater has a 12 month heating guarantee term where the customer can use the product in every season in order to experience how the system performs. We would consider this a more appropriate. 

Best Buy on Performance Guarantees: The Harmony range by Climastar


Having looked closely at both systems, we would conclude that both are a good choice for anyone wanting to upgrade their heating in preparation for winter, replacing gas or oil heating systems and going green. 

The Fischer system is generally more expensive than Harmony, does not have as many features as Harmony and looks like a traditional steel radiator. Fischer have been manufacturing heating systems for 70 years and that is a plus, however, the heater itself looks dated and is without many of the features you find today in other heating systems.

The Harmony range, in our opinion, is more aesthetically pleasing. It delivers the consumer a varied choice of 6 different styles and colourways. The heaters can be customised with pictures and images allowing personalisation. If you want a favourite image or painting as the radiator front, Climastar will arrange that for you at an additional cost. Many consumers may feel that this is worthy of the additional cost to create a uniqueness to their home. 

The Harmony range has Open Window Technology, saving energy and therefore money. It has Wi-Fi as standard, although the hub needs to be purchased at £200.00 but the hub can control as many radiators as the user has in the home, so it’s a one-off purchase. The Harmony performance guarantee seems to prioritise customer satisfaction, rather than Fischer who limit the time duration customers can test the effectiveness of their products. Regardless, it’s the technology in the Harmony system that really attracts us. 

Using the TRIAC to monitor the consumption, ensuring a constant and a consistent temperature in the room, makes it an easy choice in awarding the Harmony range as the better choice. As far as we can determine, this is a cost-effective solution compared to Fischer yet is packed with more benefits and features. Consumers looking to improve their heating system or turn to a greener heating solution will not go far wrong if they install the Harmony range

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