120kW Boiler Gas Fired Condensing

120kW Boiler Gas Fired Condensing

 

120kw Boiler gas fired condensing boiler for central heating be it radiators or underfloor heating and domestic hot water Flexiheat UK

 

Our gas fired 120kW boiler for heating commercial systems is available in natural gas or LPG gas (LPG biofuel is compatible as well).

This regular boiler can be used for space heating, central heating (radiators or underfloor heating), and domestic hot water production via accessories such as a plate heat exchanger or an indirect domestic hot water calorifier or cylinder.

They are a high-performance “A “rated efficiency , ErP-compliant condensing boiler and offer enhanced performance that exceeds the Part L building regulations for seasonal energy efficiency requirements. With low NOx Class 6, environmentally friendly emissions

Efficiency features: with a broad range of output modulation ratios of 20:1, automatic part load adjustment offers superb outputs down to 5.75 kw of heat output at 80/60 °C or 6.44 kW heat output at 50/30 °C, which leads to better heat load matching of the system, higher energy efficiencies, lower fuel consumption, and energy saving results.

This energy-efficient commercial boiler also has two stainless steel heat exchangers (2 x 60 kW) in one boiler, which ensures redundancy for your heating system; if one heat exchanger module fails, you still have  50% of your heat duty available. This enhanced performance feature can be vital for commercial customers on a site that can’t be without some heat.

120 kW wall hung gas condensing boilers

With the option of installing the boiler as a wall-to-wall solution or arranged on a suitable free-standing frame kit for floor-mounted installation, depending on site requirements.

120kw output gas fired commercial condensing boiler in natural gas or propane gas fuel with high thermal efficiencies for energy savings.

Our 120kW gas fired condensing boiler on a free standing frame kit, with low loss header and plate heat exchanger for Domestic Hot Water production.

We can provide a solution for every commercial heating specification or commercial system, as we can cascade these high performance gas boilers up to 960 kW with automatic part load adjustment with an intelligent fault system that will monitor and report any faults on these commercial specification boilers.

Commercial gas boilers high efficiency condensing boilers for heating either floor standing boilers or wall hung boilers for central heating in commercial applications - Flexiheat UK

Floor standing or wall hung gas commercial boilers from Flexiheat UK

 

120kW commercial wall hung gas boilers

As each boiler (heat exchanger) has its own flue non-return valve, you can service either boiler heat exchanger module without shutting the space heating system down.

120kW gas boiler with two heat exchangers for energy efficient low carbon central heating and domestic hot water via an indirect hot water cylinder or heat exchanger- R1K120 from Flexiheat UK

Two heat exchangers – redundancy for the heating system – a wall to wall solution

 

Our energy-efficient condensing gas 120 kw boilers are fitted with fully modulating low NOx burners (Class 6 combustion levels) for lower environmental impact.

R1K120 gas condensing boiler output and energy efficiency figures—Part L building regulations

The latest changes to Part L of the Building Regulations, which went into effect on June 15, 2023, say that all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously, 75°C plus boiler flow temperature was allowed) and preferably lower if possible to get the most condensing heat transfer from condensing boilers, which results in high energy efficiencies.

Thus, our gas boiler will produce up to 125.67 kW heat output when the heating system flow and return temperatures are 50/30 °C.

The unit will also provide 114.64 kW at 80/60 °C heat output if you have a process heating application that is not covered in the Part “L” building regulations.

Full data is shown in the following:

 

This is detailed in our full manual, which can be downloaded here.

Manual for R1K120 Gas Condensing Boilers, Internal Version, Flexiheat UK

Should you require a larger output gas boiler (we do up to 240 kW in a single boiler and up to 980 kW in a cascade system), then we do a full range of gas condensing boilers for commercial use, which are listed here.

Gas commercial condensing boiler range

Condensing boiler specifications

  • “A” ErP efficiency rating wall-hung boiler designed for commercial use or a very large home domestic central heating system and DHW for multiple bathrooms via a hot water cylinder or plate heat exchanger

  • Low Class 6 NOx flue gas emissions make these more environmentally friendly as low carbon solutions today.

  • Straightforward and easy install: all plumbing connections are at the bottom of the unit, saving installation costs.

  • Energy efficient condensing boilers up to 105.8 %  at 50/30°C flow and return hot water temperature.

  • Stainless steel heat exchanger with 28mm diameter water ways that ensure the boiler benefits from very low pressure drops, guarantees lower risks of clogging (more resistance to fouling up), greater thermal efficiency, and greater ease of cleaning.

  • Can be arranged inline for larger output requirements to cover any commercial specification, but not back to back at present.

  • These 120-kW gas-fired boilers have the identical outstanding efficiency and performance characteristics as their smaller domestic counterparts.

  • Intelligent fault system: it will monitor system pressure, i.e., if the central heating system installation pressure is too low, etc.

System pressure

  • Maximum heating operating system pressure = 3 bar
  • Maximum heating operating system pressure = 0.3 bar

Controls

  • An “Opentherm” thermostat controller, such as a “Hive” or “Nest” type, can control the boiler’s operation and temperature either locally or on the go using your phone, tablet, or computer. You can also use a basic thermostat; the choice is yours.
  • BMS compatible with our 0–10 volt free contact kit

Boiler Fuel type

This 120kw high performance boiler can be powered by natural gas or LPG applications

Dimensions of this regular boiler: 120 kW Output for central heating and domestic hot water heating

This boiler has the following compact dimensions: 670 mm wide, 485 mm deep, and 642 mm high.

Dimensions of our 120kw condensing boiler gas fired in natural gas or LPG- ErP "A" rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier from Flexiheat UK

 

Connection details at the bottom of the unit: flow and return connections, gas connection, and condensate drain.

Connection details of our 120kW condensing gas fired boiler Flexiheat UK

Free standing frame installation detail

Floor standing mounting kit

Gas fired 120kw condensing boiler on a free standing frame with low loss header Flexiheat UK

Boiler on our optional free-standing floor frame kit with low loss heating system header

120kW gas system boiler

Are these an 120kW gas system boiler? Yes, in that they have a pump (two pumps actually, i.e., one for each heat exchanger module), but at this size of system boiler, we can’t fit an heating expansion vessel within the boiler casing, so one needs to be fitted to the plumbing pipework external to the boiler to make the unit a full system boiler.

Flue options

Each heat exchanger module features its own flue exhaust connection. You can either individually flue each unit with an 80mm or 100mm flue up to 25 or 30 metres, respectively, either vertically or horizontally in range. However, if you use a split flue system, i.e., an 80mm flue diameter for the combustion air and 80mm for products of combustion, you can go up to 40 metres vertically or horizontally in range.

The last accessories option is a 100mm common flue header for the boiler.

R1K120 gas fired boiler with common flue header

Common flue header kit

Gas-fired 120 kW boilers

Should you require more product information, check stock, technical support, budget options, prices, or to order on our 120kw boiler in natural gas or LPG, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us.

Boiler flow temperature for central heating regulations Part L June 2023

Boiler flow temperature

Boiler flow temperature ? hot water heating systems in newly constructed homes or commercial buildings must now be designed to operate at a maximum flow temperature of 55°C as a result of changes to the Building Regulations.

The low flow temperature information

The latest revisions to Part L of the Building Regulations seek to reduce emissions by 31% for both new build houses and home renovations and additions, which is a crucial milestone in the UK’s journey towards net zero.

Since the year-long transition period finished on June 15, 2023 (it did not apply to work subject to a building notice, full plans application, or initial notice submitted before that date, provided the work for each building is started before June 15, 2023), the original measures that went into effect on the 15th June 2022 apply. Heating installers must be aware of the new regulations that now apply without fail.

These modifications served as a significant first step towards the Future Homes Standard, which targets reducing emissions from all new construction by 75–80% by 2025.

Part L of the building regulations

For both new builds and home extensions or renovations, the stipulated modifications to Part L define a 31% decrease in carbon emissions compared to prior requirements. Part L, which places a strong emphasis on low-carbon heating systems, also emphasises a fabric-first strategy. Changes include an improvement in fabric airtightness and insulation standards, better U-values, and thicker insulation in homes.

For buildings, Part L of the building regulations is divided as follows:

New-build homes and buildings: Part L1A Regulations

This document outlines the energy efficiency requirements for new construction. Approved Document, Part L1A

It describes how all new houses will now be valued using the SAP10 Standard Assessment Procedure (SAP) formula. This approach, which was previously derived using SAP 2012, has been updated to SAP 10. Greater insulation needs and a new target primary energy rate, expressed in kWhPE/m2 per year, are defined as a result of the SAP calculation being performed at the design stage. As a result, achieving SAP compliance will rely heavily on good water heating system design.

Additionally, all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously 75°C plus boiler flow temperature were allowed), as required by Part L1A. This will make it much simpler for houses to be retrofitted with air or ground source heat pumps in the future, when they replace a condensing boiler, be they condensing gas boilers or an oil condensing boiler as the radiators and pipework will be sized correctly for the central heating to work at these temperatures and produce maximum efficiency.

Existing properties and buildings, Part L1B

 Part L1B, an approved document, discusses energy and fuel conservation in existing homes.

Even though Part L1B acknowledges that it is not always practicable to achieve new build standards.

Quote: “Where it is not feasible to install a space heating system that can operate at this flow temperature of 55 °C or lower (e.g., where there is insufficient space for larger radiators, or the existing distribution system is provided with higher temperature heat from a low carbon district heat network), the space heating system should be designed to the lowest design flow temperature possible that will still meet the heating needs of the dwelling.

Source: HM Government – Part L 2021 edition incorporating 2023 amendments, for use in England, Page 36

Part L1B specifies that wet central heating systems that are new or being replaced shall, whenever practicable, be sized at a maximum boiler water flow temperature of 55°C.

Importantly, the regulations stipulate that if a thermal element ( wall, roof, or floor) of the home is being renovated or replaced, the work must be done to Part L1A requirements.

Commercial/non-domestic buildings are covered in Part L2a

Again, same regulations for the maximum flow temperature of 55°C or lower, but this document refers to commercial and industrial heating applications that are not domestic dwellings.

Referring document / legislation is here –

Part L2a requirements for energy efficiency compliance for commercial/non-domestic buildings

Low temperature heating advantages

Lower heating flow temperatures are now mandatory in the design of an increasing number of household heating systems, whether they utilise a gas boiler or a heat pump. Installing a condensing gas boiler on a low temperature system will result in cost savings for homeowners and reduce energy bills.

The boiler will always operate in condensing mode while the boiler temperature is set to a flow temperature of 55°C or lower. This makes the boiler and heating system far more effective and guarantees that they are always capturing the latent heat from condensation. As a result, the boiler will run as close to its condensing efficiency as possible, which will result in cheaper energy costs for homeowners.

All radiators and piping installed as part of a new or replacement system must be sized for a maximum flow temperature of 55°C, according to Part L. As a result, it could be necessary to use larger pipework and install radiators of the correct size to adequately heat the space.

When done appropriately, this work can significantly contribute to future-proofing a building so that low carbon technologies like heat pumps, which also employ low flow temperatures, can be installed in the future.

“A gas boiler will function as closely to its condensing efficiency at the boiler’s flow temperature of 55°C (55°C is the dew point temperature at which the condensing mode starts to work in gas boilers, as the flue gases condense and they can recover the latent heat), which will reduce a homeowner’s energy heating bills.”

In short, a lower boiler water flow temperature means reduced heating bills for your central heating system.

How to design and install a low temperature heating system and what to think about

Installers must take into account the wider system as well as the overall design of the building, including heat loss calculations, because the design of a low heating flow temperature system differs from that of a traditional higher boiler’s flow temperature system. By doing this, they can ensure that any future switch from a gas boiler to a heat pump can be made smoothly.

Heating flow temperature

The most important component of the regulations for the majority of installers will be Part L1(b), which focuses on the conservation of fuel and electricity in existing residential dwellings. Part L1(a) addresses the energy efficiency of newly constructed homes (learn more about what Part L means for newly constructed homes here).

It is crucial to note that it specifies that new or replacement wet central heating systems should be built to operate at a maximum flow temperature of 55°C rather than the 75°C typical of conventional heating systems to ensure boiler efficiency in modern boilers that are all now condensing boilers.

Heating system

1. A minimum of insulation All pipes linked to the hot-water storage are subject to thicknesses. Insulation must be at least 5mm thick for pipes having an internal diameter of 10mm, 10mm for pipes with an internal diameter of 22mm, and 15mm for pipes with an internal diameter of 28mm.

2. Thermostatic radiator valves are needed for every installation, with the exception of heat pump installations, which need volume for defrost.

3. For brand-new and completely replaced systems, the maximum flow temperature is 55°C.

4. Insulation is required for all principal hot water pipes used for home hot water.

5. When passing through voids, secondary central heating pipes must be insulated.

6. Multi-zoning is necessary if the total floor space is 150 m2 or greater.

7. When passing through voids, primary central heating pipes must be insulated.

8. In accordance with BS 7593, all primary hot-water and central heating circuits should be properly cleaned, flushed out, and dosed with inhibitor on each installation.

What does this mean for condensing combi boilers?

A combi boiler produces hot water on demand and has no hot water cylinder attached to the boiler, unlike a system boiler. The boiler flow temperature setting on a combi boiler for the heating side of the condensing combi boiler can be set to a thermostat temperature of 55C, and you can achieve the standard hot water temperature required of 40C for the domestic hot water side of the combi boiler with ease with our combi boiler range.

These are listed here

Our fully modulating 24kW combi boiler in natural gas or LPG  

our 35kW fully modulating combi boiler in natural gas or LPG 

or our largest combi boiler 50kw combination boiler in natural or LPG gas 

Hot water cylinders

Lower flow temperatures can cause issues for a hot water cylinder, as domestic hot water needs to be stored at 60 °C to avoid legionella. This means that the boiler flow temperature to the heat exchanger coil in an indirect hot water cylinder must be higher than the hot water temperatures within the cylinder for the heat to transfer to the domestic hot water. Newer boiler models these days have a system that will ramp up the boiler’s flow hot water temperature temporarily to achieve the correct temperature and heat the hot water cylinder.

Alternatively, immersion heaters can be used to top up the heat required for the hot water cylinder

Conclusion

Changing your boiler temperature, or now, as required, designing a lower flow temperature system, is now mandatory. Whether you’re using a combi boiler or system boilers, the boiler temperature settings must be a maximum of 55 °C and the system designed accordingly, as they have to be future-proof for low carbon heating solutions such as heat pumps.

With a boiler flow temperature of 55 °C and a return temperature that is even lower, this allows the boiler to recover the latent heat for the condensing process, lowering the heating bill / gas bills, as recommended by the energy saving trust.

70kW Boiler Gas Fired Condensing

70kW boiler gas fired condensing

70kw Boiler gas fired condensing boiler for central heating be it radiators or underfloor heating and domestic hot water in a environmentally friendly way from Flexiheat UK

 

Our gas fired 70kW boiler is available in natural gas or for LPG gas fuel (LPG biofuel compatible to). They are a high-performance “A “rated efficiency , “ErP” compliant condensing boiler and offer enhanced performance that exceeds the Part L building regulations for seasonal energy efficiency requirements. With low NOx Class 6 environmentally friendly emissions.

This regular boiler can be used for space heating, central heating (radiators or underfloor heating), and domestic hot water production via a plate heat exchanger or indirect domestic hot water calorifier or cylinder.

Efficiency features: with a modulation ratio of 20:1, the automatic part load adjustment offers superb outputs down to 3.5 kw of heat output, which leads to better heat load matching of the system, lower fuel consumption, and you’ll save on energy costs.

This energy efficient commercial boiler also has two stainless steel heat exchangers in one boiler, which ensures redundancy for your heating system; if one heat exchanger module fails, you still have up to 50% of your heat duty available. This feature can be vital for commercial customers on a site that can’t be without some heat.

The unit comes with a 2-year warranty for parts , and the heat exchanger has a 5-year warranty if, as required by the building regulations, a dirt and air separator is fitted to protect the system, and the product is serviced annually.

70 kW wall-hung gas condensing boilers

With the option of installing the boiler as a wall-to-wall solution or arranged on a suitable free-standing frame kit for floor-mounted installation, depending on site requirements.

Gas condensing boiler, which is a regular boiler on a free-standing frame kit the R1K range 50kw to 120kw outputs from Flexiheat UK

The 70kW gas fired condensing boiler mounted on a free-standing frame kit with low loss header and plate heat exchanger of domestic hot water production.

We can provide a solution for every commercial specification, as we can cascade these high performance gas boilers up to 960 kW with automatic part load adjustment if so required.

commercial gas boilers; commercial lpg boiler; wall hung gas commercial boilers; commercial boilers in cascade which are a regular boiler

70kW commercial wall hung boilers

As each boiler (heat exchanger) has its own flue non-return valve, you can service either boiler heat exchanger module without shutting the space heating system down.

Our energy-efficient gas 70kw boilers are fitted with fully modulating low NOx burners (Class 6 combustion levels) for lower environmental impact.

70 kW gas boiler with two heat exchangers for energy efficient low carbon central heating and domestic hot water via an indirect hot water cylinder the R1K75 from Flexiheat UK

Two heat exchangers for redundancy in one boiler casing with an output of 70 kW

R1K75 gas condensing boiler output and energy efficiency figures—Part L building regulations

The latest changes to Part L of the Building Regulations, which went into effect on June 15, 2023, say that all new wet central heating systems should be sized for a maximum heating flow temperature of 55°C (previously, 75°C plus boiler flow temperature was allowed), and preferably lower if possible to get the most condensing effect from boilers.

Thus, our gas boiler will produce up to 79.35 kW when the heating system flow and return temperatures are 50/30 °C.

The unit will also provide 72.83 kW at 80/60 °C if you have a process heating application that is not covered in the Part “L” building regulations.

Full data is shown in the following:

R1K75 gas condensing boiler output and energy efficiency figures Flexiheat UK

Output and energy efficiency figures for our R1K75

 

This is detailed in our full manual, which can be downloaded here.

Manual for R1K 75 Gas Condensing Boilers – Internal version Flexiheat UK

Should you require a larger output gas boiler (we do up to 240 kW in a single boiler and up to 980 kW in a cascade system, then we do a full range of gas condensing boilers, which are listed here.

Commercial gas condensing boiler range

Specifications

  • “A” ErP efficiency rating wall-hung boiler designed for commercial use or a very large home domestic central heating systems and DHW for multiple bathrooms via a hot water cylinder.
  • Low Class 6 NOx flue gas emissions making these more environmentally friendly.
  • Straightforward and easy install: all plumbing connections are at the bottom of the unit saving installation costs.
  • Energy efficient condensing boilers up to 105.8 % at 100% heat input at 50/30°C
  • Stainless steel heat exchanger with 28mm diameter water ways that ensure the boiler benefits from very low pressure drops, guarantees lower risks of clogging (more resistance to fouling up), greater thermal efficiency, and greater ease of cleaning.
  • Intelligent fault system: if the boiler has a fault, it will tell you exactly what has gone wrong, i.e., if the heating system installation pressure is too low, etc.
  • Maximum heating operating system pressure = 3 bar
  • Maximum heating operating system pressure = 0.3 bar
  • An “Opentherm” thermostat controller, such as a “Hive” or “Nest” type, can control the boiler’s operation and temperature either locally or on the go using your phone, tablet, or computer. You can also use a basic thermostat; the choice is yours.
  • BMS compatible with our 0–10 volt free contact kit

 

Dimensions of this regular boiler: 70 kW Output for central heating and domestic hot water heating

This boiler has the following compact dimensions: 670 mm wide, 495 mm deep, and 642 mm high.

Dimensions of our 70kw condensing boiler gas fired in natural gas or LPG- ErP "A" rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier from Flexiheat UK

A small compact energy efficient gas condensing boiler 70 kW with ErP “A” rated for central heating (radiators or underfloor heating) and domestic hot water via a calorifier.

Connection details at the bottom of the unit: flow and return connections, gas connection, and condensate drain.

Connection details of the 70kW condensing gas fired boiler Flexiheat UK

Free standing frame installation detail

Floor standing mounting kit

Gas fired 70kw output condensing boiler on a free standing floor frame kit with low loss header Flexiheat

Boiler on our floor free standing frame kit with low loss heating system header option

 

70kW gas system boiler

Are these an 70kW gas system boiler? Yes, in that they have a pump (two pumps actually, i.e., one for each heat exchanger module), but at this size of system boiler, we can’t fit an expansion vessel within the boiler casing, so one needs to be fitted to the plumbing pipework external to the boiler to make the unit a full system boiler.

Flue options

Each heat exchanger module features its own flue exhaust connection. You can either individually flue each unit with a co-axial flue (80mm/125mm) should you wish to go room-sealed up to 10 metres vertically or horizontally in range. However, if you use a split flue system, you can go up to 40 metres vertically or horizontally in range.

The last option is a common flue header for the boiler.

R1K75 gas boiler with common flue header option

Common flue pipe header option

Gas fired 70 kW boilers

Should you require more product information, check stock, technical support, prices, or to order on our high performance 70kw boiler in natural gas or LPG, then please don’t hesitate to contact our sales team on 01202 822221 or use our email contact form via the contact tab above to message us. Follow our business on Facebook or Twitter if you’re interested in being informed of our latest recommend manufacturer product range items deal.