As the UK moves towards its net carbon zero goals, the installation of underfloor heating systems is growing in popularity. However, it’s not without its pitfalls. This article looks at seven of the most common mistakes made during UFH installations and why it’s best to avoid them.
The base floor must be properly prepared ahead of installing the UFH system. The screed, thermal insulation and UFH pipes cannot be put down on uneven surfaces. Careless preparation of the base skipping the levelling and cleaning stage means it will not provide stable support for the screed, leading to cracking. If the screed cracks, there is a risk that the UFH pipes will be damaged and may leak. If the base floor is not completely dry before laying the finished floor, there is the possibility of unpleasant odours, fungi and mould developing. As well as in the case of tiles not sticking and they start debonding.
It’s easy to overlook the pipe conduit when you’re pressed for time, but doing so can seriously affect the UFH system post-installation. The conduit acts as a protective sleeve where pipes rise from the screeded floor or travel through an expansion strip. It is important to protect the pipe with conduit as it protects the pipework from damage and insulates the pipe, thus preventing an excessive build-up of heat in one area, which can often cause overheating in some areas. The time invested in installing conduit on your UFH pipes will result in a better system output and greater customer satisfaction. It could save you from being called back for remedial work later.
It’s essential to properly fill the UFH system to ensure no air is trapped, which could cause poor performance. In addition, by properly filling the system, you can be confident that it will operate effectively once the final commission is complete.
The key points to note when filling the system are:
A pressure test is a vital element of ensuring the UFH system is fit for its purpose, as it’s critical to ensure the pipework operates without leaks when pressurised. Pressure tests should be completed at 4-6 bar for a minimum of 1 hour before reducing to working pressure (1-2 bar) before laying flooring or screed. The test allows you to check for leaks and that the pipes are expanded to ensure good heat transfer once the screed is dry.
Ensure you complete the pressure test with water or air if there is a risk of frost.
Check out our video on performing a UFH system pressure test.
Modern UFH systems are compatible with a huge variety of floor coverings. Still, you must know what finish your customer wants to install before your Multipipe quote is finalised, as the type of floor covering determines the heating efficiency. For example, ceramic tiles have a very different thermal output compared to carpet. Not taking account of the final kind of floor covering can mean the difference between a system working or not (imagine covering all radiators in a blanket!).
Our bespoke UFH solutions come with a full drawing plan to aid installation. We highly recommend following this plan as it’s created to ensure the system operates at maximum efficiency and provides the heat output required. The project is also designed to ensure that you have the right amount of materials for the job – deviating from the plan may mean that you run out of equipment and incur additional costs. Also, using the hydraulic balancing information will help to speed up your commissioning time and ensure all rooms heat evenly.
It’s easy to think you’re saving your customer a few pounds by not running UFH throughout the entire room, for example, under the kitchen units or island, but this is not a smart move long term. With proper care and maintenance, your Multipipe UFH system will likely last at least 50 years. However, the homeowner will probably change their kitchen design at least once in that timeframe. By failing to install UFH under the units, you risk leaving them with cold spots in the future. Contrary to popular belief running the system under units will not cause damage or the contents of the cupboards to overheat.
By avoiding these mistakes, you’ll be well on your way to a perfect UFH install that will provide comfortable warmth for your customer for years to come.
When requesting a quote for a bespoke Multipipe UFH system, you can be sure we’re on hand to offer advice at every stage. For example, we can help calculate heat losses, ensure you have the right materials and the correct amount of them, and advise on the best system for the floor type on your project. To learn more about Multipipe’s UFH solutions click here
In December 2021, the UK Government announced the first major changes to the Building Regulations in nearly a decade by releasing the latest approved documents affecting parts L, F & O. The Future Homes Standard (FHS) is due to be implemented in 2025. The new building regulations form part of the Government policy to achieve the FHS.
The FHS dictates that new homes need to produce at least a 75% reduction of CO2 emissions. Therefore, the recently released Part L version aims for an average decrease of 27% to 30% in CO2 emissions. The decrease provides a springboard to the upcoming requirements of the Future Homes Standard. As a result, all new heating systems will have to be designed with a maximum flow temperature of 55°C or lower from June this year.
The regulations provide flexibility on meeting the targets, and there are a variety of renewable energy sources already on the market, providing installers with options to suit different types of buildings. However, the Government expects heat pumps to become the primary heating technology for new homes. In addition, there is also a requirement for automated and zoned control devices.
By their very nature, water-based underfloor heating systems can easily comply with the new, upcoming requirements and present other benefits for the installer and the homeowner.
Underfloor heating systems cover a greater surface area than radiators. Therefore, such systems should run 24 hours a day at a lower temperature (35-55°C rather than 80°C for gas boilers) for maximum efficiency. When a heat pump runs at 35°C, UFH can perfectly accommodate the optimal coefficient of performance (COP) for heat pumps. UFH can also be fully zoned, ticking a crucial regulatory box and ensuring the end-user wastes less energy.
Much has been reported on the cost of heat pumps and UFH compared to traditional boiler/radiator systems. Still, as long as a heat pump is suitable for your project, there may be some further benefits to the investment. In addition to compliance with the upcoming changes, and thermal comfort, installers can also advise end-users that they are likely to benefit from reduced operational costs.
Compared to traditional radiator systems, a UFH system should be cheaper to run between 15% and 40%. In addition, UFH systems require very little maintenance and will likely outlive the building itself. End-users can be offered further reassurance as standard radiators are often replaced every 10 to 20 years, whereas Multipipe offer a 50- year warranty on our MLCP pipework.
UFH also offers a number of safety, health, and aesthetic benefits and future-proofing new properties per the new Part L regulations.
The absence of radiators maximises the available wall space and provides the kind of clean lines modern homeowners favour. In addition, it makes every area in the home a little safer, while air quality within the property is also improved by significantly reducing household particle movement.
Our industry faces many real challenges to ensure we can all meet the requirements of the FHS. For example, upskilling tradespeople to ensure our industry has the number of highly trained individuals needed to install lower carbon heating solutions to their customers.
The Government needs to provide further clarification on some elements of the regulations. For example, suppose a wet heating system has been newly installed or fully replaced in an existing building. In that case, it should be sized with a maximum flow temperature of 55°C or lower whilst allowing the system to meet the heating needs of the building. This needs to push harder the requirements of insulating the property to ensure less leakage, which some house can then run risk of condensation is sealed too much.
If this is not possible, the system must be designed to the lowest design temperature feasible whilst still meeting the heating needs of the residence. Therefore, a ‘Good Practise’ specification appendix has been added for a new home designed to be heated by a heat pump.
Uplifts to Part L and F have new minimum efficiency standards for existing homes. These include a new way of calculating whole house heat losses for new extensions. A transition period now starts, which will end in June 2022, when these new regulations will come into effect.
There are still five months before the regulations apply, so we recommend familiarising yourself with the requirements of the updated rules. It’s also worth thinking about your planned new build work to ensure you know which parts of Part L will apply to your projects.
For projects with plans or notices submitted before June, there’s a cut-off date of June 2023 for the building to start for the current Part L (2013) to apply. From that point on, older versions of Part L will no longer apply to any projects, regardless of when the plans or notices were submitted.
Any plans or notices submitted after June next year must adhere to the new interim Part L standards.
It is also worth bearing in mind that this is a very short interim period, with 2025 ushering in the next Part L update. Although the proposed technical specification will not likely be available until 2023, the Government has indicated the U-values it will expect.
Accuracy is vitally important in designing and installing a heat pump system to ensure efficiency and avoid inflated energy bills compared to a traditional gas boiler system. You must calculate heat losses to ensure the end-user has a system that meets their temperature requirements. When requesting a bespoke Multipipe UFH system, we will help ensure the system is fit for purpose by helping with these calculations.
It is an extremely busy time as the industry absorbs building regulations’ changes and their impact on working practices. To help installers adapt as quickly as possible, we’re here to help with training and technical advice for all Multipipe systems.
As underfloor heating installation grows increasingly popular, it’s important to understand the critical parts of a UFH system and how they operate. This post will explain what a manifold is and how it works.
Manifolds are the central control hubs of water in underfloor heating systems. They manage water flow rates and any room zoning you have. In addition, manifolds work to circulate heated water through the UFH pipes to provide each system zone with comfortable, energy-efficient heating.
Manifolds are crucial parts of a water-based underfloor heating system. They connect the heat source to the underfloor heating pipework and act as the termination point for the floor circuits (pipework). Manifolds circulate heated water from the heat source (e.g. boiler) through the underfloor pipework whilst controlling the flow rates. If a mixing unit is used, they also control the circuit temperature.
Hydronic underfloor heating systems generally consist of pipework installed on specific UFH insulation boards or within the screed. UFH pipework can be laid in various patterns (e.g. bifilar) to form circuits. A single circuit will be for an individual room or area and multiple circuits for larger rooms or open areas – these areas are called zones. Each zone connects to a centrally located manifold, allowing independent control of the zones. In addition, manifolds can control multiple circuits simultaneously, allowing you to warm different rooms to different temperatures. Each zone is typically managed by a zone-specific thermostat installed within the heated area.
Multipipe has a range of manifolds that can control the underfloor heating for up to 12 circuits, each with up to 120 meters of connected pipework. Our manifolds will maintain a consistent and even distribution of the water around the floor circuits at the correct temperature and flow rate.
Manifolds comprise six key parts, each performing a vital function in the effective operation of the underfloor heating system.
A wiring centre controls the electrical aspect of the underfloor heating system. It enables a connection between the heat source, thermostat and manifold. The wiring centre coordinates the heating system’s operation as it usually connects the Room thermostats to the individual rooms (using actuators) and centralises the pump and boiler operation.
A mixing unit (if fitted) comprises of three main parts: the mixing valve, circulating pump and the top assembly (consisting of air vent and temperature gauge). It helps blend incoming boiler water temperature to a safe operating temperature for the floor circuits. This helps to keep at the designed temperature. The main reason for using this is that you have a system that needs to operate at different water temperatures, i.e. Radiators that cannot run at low temperatures. You set the heat source to the desired flow temperature for the rad system to work, then locally blend the water for the UFH circuit.
Air vents and drain valves are found on the manifold’s ‘flow’ and ‘return’ bars, and their function is to help in the initial filling and venting of the UFH system.
Flow Gauges are mounted to the flow bar of the manifold, one per circuit. These help you to see the flow rate through each zone. The flow gauges are set during installation to configure the correct flow rate for the circuit and provide the designed heat output for that circuit – which is determined by the floor build-up and heat losses of the area.
Isolation valves permit the isolation and testing of the manifold without affecting the rest of the system. These valves are connected to the manifold bars or the Mixing Unit (if used).
The Valve Pins (these sit on the return bar of the manifold) allow the system to be filled, drained, and pressure tested by controlling water flow through the individual floor circuits. Once this operation is complete, the Valve Caps are removed and replaced with Actuators to provide individual circuit control.
Actuators connect to the wiring centre and are attached to the valve pins of the manifold. This connection allows the actuators to open and close each circuit so the water can flow through the system. Allowing for individual room control.
The manifold connects the heat source (such as a boiler or heat pump) with underfloor heating pipes and regulates the incoming water temperature via the mixing unit. The manifold then sends this warm water through all the floor circuits to create an energy-efficient heating solution.
A UFH manifold consists of a flow bar (with flowmeters) and a return bar (with valve pins). This allows water to flow down the separate pipe circuits installed into individual zones. Each area can be balanced and individually controlled as required by the end-user.
The top row has adjustable valves with a see-through cap that shows the flow rate. The flow rate increases or decreases by turning the valve. This allows the system to have the desired flow rate in each circuit.
For example, if a 100m coil is in the sitting room and a separate 80m loop in the kitchen, both pipe sets will return to taps on the manifold. Due to the different pipe lengths, adjustments will need to be made to ensure they balance, as water will always take the easier route and starve the sitting room circuit.
The bottom bar is where our actuator control sits to control each loop.
The primary heating circuit connects to the heat source, which supplies water to the manifold (via the mixing unit if used). The heat source provides water to the manifold mixing valve to guarantee the intended water temperature (usually 20 – 60°C). However, if the heat source can constantly give the required water temperature without over-heating, you probably won’t need a mixing unit, which helps with the efficiency of your heat source.
The mixing unit regulates the water temperature by a wax-filled thermostatic head as heat passes through the wax melts; as a liquid, this takes up less space, so it shuts the valve as it resolidifies the wax expands, pushing the valve open again. This then blends the heating water from the primary circuit with cooler water from the floor circuits to achieve the desired heating temperature. This temperature is configured during the installation to match the designed heat requirements, which are affected by heat losses, floor construction and heat outputs.
When the flow rates are correct, the manifolds flow bar delivers optimally heated water into the floor pipes. After circulating, the water goes back to the manifold via the return bar. The return bar has circuit valves usually mounted with actuators. The thermostat instructs the actuators to open and close to allow water to flow into the floor circuits to warm the room as required.
The Wiring Centre efficiently controls the manifold and its electrical components. The wiring centre connects the heat source, thermostats, manifold actuators, pumps, and zone valves. For example, if a thermostat calls for heat in a specific zone, the Wiring Centre will supply voltage to the relevant Actuators. By opening the Valves Pin, warm water can flow through the circuits. The Wiring Centre also demands heat from the boiler, opens any zone valves fitted and operates the Mixing Unit Pump.
Multipipe have a range of smart programmable thermostats that allow users to control their heating remotely when combined with a smart gateway. The use of smart thermostats helps reduce the end users’ carbon footprint and provide long-term savings on energy bills.
The position of the manifold can greatly influence the efficiency of a UFH system. The ideal location for the manifold is central to the heating zones. The location should be somewhere that can easily be accessed for future maintenance. In addition, a central manifold location will help ensure that pipe feed lengths are kept to a minimum, thus ensuring that the water evenly and efficiently reaches each area of the system, ensuring no overheating.
More than one manifold may be needed for larger projects. For example, if underfloor heating is to be installed across multiple floors, we recommend installing a separate manifold on each floor.
In a standard installation, it is usual to see a separate manifold for each floor of the property.
However, where the home has underfloor heating downstairs and radiators upstairs, it is possible to use only one manifold if the radiator circuit is plumbed in a traditional branch system.
If you choose a manifold for the radiator circuit, then you can;
Suppose you can size radiators to operate at a lower temperature (generally by increasing their size). Then you don’t have to fit mixing valves. Then turning the heat pump/boiler to a lower temperature/heat curve can massively increase your system efficiency.
However, care must be taken to balance the system as the two systems run differently. For example, the radiators could have a lot less resistance than the underfloor heating circuits and therefore get the lion’s share of the heat, leaving the underfloor heating circuits starved.
Most new installations are an unvented system. Therefore, It is covered by Part G of the Building Regulations, which requires that the manifold be installed by an experienced and suitably qualified professional. It is up to the installer to consider the end-users wishes as to the location. Ultimately the manifold must be installed in a safe and efficient site.
Multipipe provide a design and supply service for bespoke underfloor heating systems and manifold radiator solutions. We will work with you to ensure you install an optimal system, including advice on locating the manifold.
You’ll find helpful videos regarding UFH installation on our YouTube channel
The new year is often when people start to make resolutions to help them shape their year and improve their lives and work. So why not get ahead of the curve and read our top 5 tips on how to work smarter with Multipipe in 2022. If these make it on to your new year resolutions, you’ll find they are easier to stick to than the new diet!
We’ve said it before, but it’s one of our favourite ways to work smart. So instead of throwing your 16mm MLCP offcuts from your underfloor heating projects, why not use them for your plumbing projects instead. Good for your budget and better for the environment. A win-win!
Visit https://www.multipipe.co.uk/product-category/mlcp-plumbing/coils-12-32mm/ to see our range of MLCP coils
Ten reasons to swap to MLCP
Want to know when to use coils vs straight lengths?
We’re now able to personalise your UFH to a far greater extent to ensure the perfect system for your customer. Send us your heat loss data and we will adjust the system to match the demand and optimise performance. We’ll use your heat loss data to adjust the system to meet the actual demand is and ensure it even works with ultra-low temperature systems. Just remember to send this information in with your next quote request.
If you’d like the fastest turnaround on your underfloor heating quote, make sure you send us all the details we need to ensure an accurate price for you and your customer. And a decent set of plans really helps too!
Watch now: https://www.youtube.com/watch?v=-ZN3nDs9FaA
Multipipe.co.uk is available 24/7 to place orders, check pricing and access technical datasheets. If you have a trading account with us you will see your personalised pricing and can charge your credit account. If you’re new to Multipipe apply for a free web trader account and receive a further 10% off the web pricing.
No matter how experienced you are we believe there is always an opportunity to learn something new. Or maybe just reassure yourself that you’re at the top of your game! We have released a huge range of easy-to-follow playlists covering plumbing techniques and the installation and commissioning of UFH systems. Why not grab a cup of tea and have a watch? They are short, to the point and you never know you might learn something new.
The latest government announcement offers homeowners an incentive of up to £5,000 to fit a renewable source heat pump instead of a gas boiler in a bid to help the UK meet its net carbon goals.
For the end-user, this may seem an excellent benefit when it comes to finally changing their boiler because according to the energy-saving trust, it costs an average of £2,300 to replace a boiler, and a heat pump can be between £6,000-£8,000, of course, this depends on system size and complexity. So, having £5,000 knocked off the bill will be very tempting to the end-user.
However, the issue is not as simple as it may first seem. We’ve listed some potential challenges below, with assumed costs so you can see where the pitfalls may lie.
What seems to be missing with this grant is the lack of focus on increasing the home’s efficiency first. With over half the UK houses being 1980’s and older, we can expect to heat losses of around 60w/m² + per room. Meaning the demand for the emitter and, more importantly, the heat pump is huge. Therefore, for a heat pump to operate effectively, the home must reduce its heat losses to significantly affect carbon reduction and cost. Below are some indicative prices to insulate a standard size UK home.
The other most important feature is the emitter. If we are talking about a power flush, fit and leave type install, you will be going behind radiators that are sized based on an 80°C flow. A heat pump will not operate at this flow rate, so you have halved the temperature, which essentially halves the output. The customer is potentially left with a system that runs constantly and never reaches what they consider an acceptably warm temperature (for both heating and hot water). Then they see the eye-watering electric bill.
So, we should recommend refitting new, larger radiators or UFH to ensure that they meet the heat loss. If the suggested insulation listed above has been installed, the effect of heat loss is lowered. However, suppose the insulation isn’t suitable. In that case, bigger radiators will be needed, and the lower difference required between flow and return may mean that a new piping system will be required at an additional cost.
The short answer (and most of us know) is No, due to these reasons.
Until the insulation, pipework and radiator sizes are addressed, the potential for heat pumps to work effectively in older properties is low. So, now for the scary bit. Suppose you do the right thing and quote around £25k to upgrade insulation, swap the emitters and install a suitable heat pump. In that case, you will be laughed at because no doubt less professional installers will say they can do the work for just over the cost of the available government grant. However, the homeowner will be left with an unfunctional system and high running bills and wishing they kept their old gas boiler.
Ok, so after all this, because the efficiency of heat pumps is high (and they are!), you can look at around 400% efficiency, so for every kW of electric use, you get 4kW of heat energy. This will decrease the warmer you run a temperature, so keeping the flow temperature low is essential. But currently, electricity is four times the gas price, so there are no current running cost savings! Of course, the gas price will always rise, and we hope electricity will fall, but again this is another issue out of our control.
The other thing to consider is basic physics. Heat pumps work by absorbing low energy outside the property and compressing it, amplifying its energy potential. This is great and super efficient during temperate days. But when the energy outside is low, the amplified energy is also low, so the unit works harder. So, your efficiency is not as good on very cold days (the days you need heating the most).
Am I against heat pumps? Not at all, but do I think they have to be very carefully considered? Yes! And are they suitable everywhere? No!
So, are heat pumps the future? I feel it is the government’s job and authoritative bodies to ensure the advice given on the scheme is the best for our customers. Here’s the link to the government website to see if you’re eligible for the boiler upgrade scheme.
If you are considering a heat pump you might want to pair it with underfloor heating – our range of UFH systems can be seen here
What do you feel about this scheme? Comment on our social channels as it would be nice to hear what you think.
When selecting thermostats for a client, do you base it on the ease of use, aesthetics, price or maybe all three? There is the fourth point with UFH systems that is often overlooked and yet is the most important of all. Read on to find our why you need the right thermostat for your UFH system.
As explained in a previous #TechTuesday articles, UFH does have a slower reaction time when compared with other heating types. Due to these slower reaction times, it is better to maintain a constant temperature and only make small adjustments.
Luckily room control technology has come a long way since the simple dial thermostat. Even though these are very easy for clients to use and extremely cheap, they are terrible for UFH as they suffer from over and undershoot of a minimum of 1 degree. This level of inaccuracy helps with radiators as it ensures the boiler does not constantly fire. Unfortunately, with UFH, the residual energy left after the boiler fires can overshoot the system by more than 3 degrees.
Similarly, it then takes an age for it to drop back down, and by that point, all the energy is lost in the screed, causing it to undershoot massively. Thus, using simple dial thermostats with a UFH system can make the building uncomfortable and highly inefficient.
All modern UFH controls should have a version of Load compensation. The load compensation feature forecasts where the system is currently measuring and reacts before it needs to. In this way, the system ensures it keeps close to the setpoint without overheating and underheating, saving huge amounts of money in wasted energy and increasing comfort.
Why not talk to our team about our range of load compensated controls today? And we will ensure your next UFH is not just easy to use, looks good and is cost-competitive but is also efficient. Click here to see our range of thermostats.