Electric boiler for underfloor heating systems

An electric boiler for underfloor heating is the ideal wet electric heating solution for residences, including homes, apartments, flats, and rural properties that seek heating through renewable electrical energy, as well as for properties that do not have a mains gas supply but do have access to mains electricity.

The underfloor heating system can be a central heating system for the whole property, or you can use the electric boiler for a dedicated underfloor heating system that may be installed in a conservatory or an annexe within the house or property.

Wet electric underfloor heating systems or radiant floor heating are classified as hydronic or “wet” systems, differing from “dry” electric underfloor heating systems that use embedded electrical cables in the floor.

Electric boilers have high energy efficiency at nearly 100%, which reduces running costs.

Underfloor heating systems

Electric boilers provide consistent and even heat through radiant heat, eliminating cold spots commonly found with radiators.

The main benefits of electric underfloor heating include even heat distribution, space-saving, aesthetic appeal, and installation flexibility.

Because underfloor heating distributes heat both horizontally and vertically, there is no temperature fluctuation from the floor to the ceiling, providing exceptional thermal comfort with a radiant floor heating system.

Electric boilers for underfloor heating are ideal for homeowners or housing projects looking for an environmentally friendly, compact, and low-maintenance way to heat their flats or homes.

Electric-powered boiler for underfloor heating product range

Our electric boiler for underfloor heating range consists of the following models for up to 24 kW of output:

Firstly, we would like to introduce our 8kW electric boiler designed for underfloor heating.

FHMN3-8  The 8kW electric system boiler features an outdoor sensor, a 5-litre expansion vessel,circulating pump and is PV solar-ready, and has an adjustable output range of 2kW, 4kW, 6kW, and 8kW, with options for 230V or 400V 3 phase power.

This electric boiler modulates to the following heat output steps: 

0.8kW, 0.9kW, 1.3kW, 2kW, 2.6kW, 3.3kW, 4kW, 4.6kW, 5.3kW, 6kW, 6.6kW, 7.3kW, 7.9kW

So yes, this electric central heating system boiler can be set to either 2kW, 4kW, 6kW or 8kW (technically 7.9kW, but close enough to 8kW for us), and the boiler will ramp up and down the above modulation scale depending on what the heating system demands.

This is the ideal small electric boiler for underfloor heating.

This electric boiler is the best option for those seeking a 6kW electric boiler to meet underfloor heating requirements in flats or small apartments and much cheaper than a heat pump for example.

The next size up boiler is our 14kW electric boiler for underfloor heating.

The FHMN3-14 is a 14 kW electric system boiler that includes an outdoor sensor and a 5-litre expansion vessel,circulating pump, and is PV solar ready, and has an adjustable output range of 6.9 kW, 9.2 kW, 11.5 kW, or 13.8 kW, operating on 1 phase/230 volts only.

This electric boiler modulates according to the following heat output steps: 

0.8kW, 1.5kW, 2.3kW, 3.5kW, 4.6kW, 5.8kW, 6.9kW, 8.1kW, 9.2kW, 10.4kW, 11.5kW, 12.7kW, 13.8kW 

This electric boiler can be set to either 6.9 kW, 8.1 kW, 9.2 kW or 13.8 kW (technically 13.8 kW but close enough to 14 kW for us), and the boiler will ramp up and down the above modulation scale depending on the heating system’s demands.

This electric boiler is the best option for those seeking a 12kW electric boiler  to meet underfloor heating requirements.

The largest model in this range is our 24kW electric boiler designed for underfloor heating.

FHMN3-24: A 24 kW electric boiler with an outdoor sensor, cascade, 5-liter expansion vessel,circulating pump and is PV solar-ready, with 12 kW, 16 kW, 20 kW, or 24 kW adjustable output range—400 Volt, 3 Phase power supplies only.

This 24 kW electric boiler modulates to the following heat output steps: 

1kW, 2kW, 4kW, 6kW, 8kW, 10kW, 12kW, 14kW, 16kW, 18kW, 20kW, 22kW, 24kW

This electric boiler can be set to either 12 kW, 16 kW, 20 kW, or 24 kW, and it will ramp up and down the above modulation scale depending on what the heating system demands.

Boiler features

We also can supply the FHM3-designated version with no expansion vessel for open vent systems, but a minimum 5-metre head (0.5 bar of pressure) is required for these boilers to work, again from 2 kW to 24 kW heat output. The system boiler option or unvented boiler system option both have the following features:

• PV solar panel compatible – Maximise energy produced from PV solar panels to reduce energy bills, reduce reliance on fossil fuels and reduce carbon emissions.
• An outdoor weather sensor and an indoor room sensor are included as standard for weather compensation of the underfloor heating central heating system, which helps reduce energy consumption, lower running costs and less energy usage, which means lower carbon emissions from the boiler.
• The outputs range from 2 kW to 24 kW and can be adjusted on-site to achieve the required home heating performance for the underfloor heating.
• These energy-efficient electric system boilers have an automatic anti-Legionella feature when using an indirect hot water cylinder to heat water for sanitary use.
• Installation – New boiler or replacement boiler installation in renovation projects is easy; the units are compact and can fit in a small space. Just supply the mains electricity cables to the boiler. There are no gas lines or flue systems to install, unlike with gas or oil boilers.
• You can use our electric boilers for both underfloor heating and radiators by utilising our additional heating circuit modules. Technically you can have up to 24 heating circuits from one boiler for underfloor heating and/or radiators.
• External thermostat compatible to reduce running costs.
• Low maintenance cost and servicing expenses. No need for a yearly safety certificate from a gas safe heating engineer with an electric heating boiler unlike a gas boiler.
• Warranty on these boilers is 24 months.
• Suitable for heating systems with a pressure between 0.5 bar to 3 bar maximum.
• Our “FHM” series of electric boilers have a hot water flow outlet temperature range of 20°C to 85°C.
• Really suited to locations that don’t have a mains gas supply that require a boiler for underfloor heating

 

These underfloor heating boilers may be easily controlled from a distance using an app (an internet module is required), allowing you to keep tabs on energy usage and create personalised heating schedules.

 

 

For full details on this range, the brochure is here for direct download

M range electric heating boilers brochure from 2kW to 24kW of output Flexiheat UK 

Manual for this range is here:

M range electric boilers technical and installation manual 2kW to 24kW from Flexiheat UK

Boiler demands over 24 kW – “FHEL” Electric Boiler Specifications

This line is our “FHEL” producr range and has 3 models; these are 3-phase power supplies powered boilers at these kW heat outputs. These units are suitable for larger apartments, flats, houses,housing projects or commercial properties with 3 phase mains electricity power.

FHEL30 – 30kW Standard Series Electric Boiler, three phase 400V – 3 x 48 Amps at maximum output

Output can be set to either 5, 7.5, 10, 15, 17.5, 20, 25, 27.5 or 30 kW, and the boiler will ramp up and down to the maximum power output set.

 

FHEL38 – 38kW Standard Series Electric Boiler, three phase 400V – 3 x 60 Amps at maximum output

Output can be set to either 5, 10, 12.5, 17.5, 22.5, 25, 30, 35 or 37.5 kW, and the boiler will ramp up and down to the maximum power output set.

 

FHEL45 – 45kW Standard Series Electric Boiler, three phase 400V – 3 x 72 Amps at maximum output

Output can be set to either 5, 10, 15, 20, 25, 30, 35, 40, or 45 kW, and the boiler will ramp up and down to the maximum power output set

These three boilers for underfloor heating can also be linked into an indirect hot water cylinder for DHW production, as per the diagram below on this webpage.

Maximum flow temperature for our “FHEL”electric underfloor heating boiler range is 80°C

Brochure is here for direct download

Download the Flexiheat Brochure For Electric Boilers “FHEL” Range

Manual is here

Download the Flexiheat Electric Central Heating Boilers – Installation & User Manual – FHEL Boilers

Wet underfloor heating central heating system

The water temperature for underfloor heating can be adjusted to a range of different settings, with the optimum wet underfloor heating floor temperature often falling somewhere between 23°C and 27°C. However, the optimal water temperature for underfloor heating systems flow temperature commonly ranges between 35°C and 55°C (which is still a low temperature for a heating system), dependent on the kind of flooring material and the insulation levels of the property, which ensures both comfort as the heat radiates upwards from the floor, resulting in even room heating, energy efficiency and lower running costs.

A professional heat loss calculation is essential to determine the appropriate size for the electric boiler for your underfloor central heating scheme.

It is vital to ensure floor-type compatibility with electric underfloor heating to optimise heat transfer.

Underfloor heating systems can be combined with radiators in the same home.

A qualified heating engineer can help ensure that an electric boiler is compatible with an underfloor heating system.

Heating and hot water cylinder

The power output of the electric boiler must match the home’s total heating and hot water demand.

Normally 3 kW per person is added to the boiler central heating requirement for the domestic hot water/sanitary warm water requirements for the house or flat, up to 6 kW in total.

As normally the indirect hot water cylinder comes with an immersion heater, which heats the domestic hot water overnight, which is used throughout the daytime (the tanks are so well insulated they hold the water temperature all day). The added kW is usually unnecessary, but on cold days or during high hot water demand, it ensures that the DHW can quickly and efficiently heat the water.

Electric boiler versus a gas boiler for underfloor heating?

Gas heating for underfloor heating (via an LPG or natural gas boiler) is still a popular option; however, electric boilers have some advantages –

• Electric boilers are typically simpler to install and require less maintenance compared to gas boilers.
• Electric boilers are generally quieter than gas boilers.
• Electric boilers are highly efficient, with an efficiency close to 100%—gas or oil boilers are normally 92% energy efficient at most when working in a condensing operation.
• Electric boilers don’t burn fossil fuels, contributing to environmental benefits.
• Electric boilers do not produce combustion products, which eliminates the need for a flue system, resulting in lower installation costs.
• Utilising time-of-use or off-peak electricity tariffs can help reduce energy bills and manage operating running costs for an electric boiler for underfloor heating.
• Safety: there is no risk of an explosion or carbon monoxide poisoning in the house from leaking flue gases that can kill, as with a suitable gas or oil boiler.
• Underfloor systems are hidden, offering a space advantage and improved aesthetics to the room and the house overall.
• Electric heating systems can benefit from low tariff electricity rates, such as Economy 7 cheap rate electricity.

Best electric boiler for wet underfloor heating systems

For more detailed information, stock availability, delivery times, price or to purchase our cost-effective and energy-efficient electric boilers for underfloor heating for flats, small or large houses, or even commercial underfloor central heating schemes.

Please contact our sales team at 01202 822221 or use our website’s email contact form to discuss your requirements.