What Is a Thermostatic Radiator Valve (TRV)?

A thermostatic radiator valve (TRV) is a valve that is fitted to a radiator in order to control the flow of hot water through the radiator. This allows you to control the temperature of the room in which the radiator is located.

How does a TRV work?

TRVs work by sensing the air temperature around them. When the air temperature reaches the desired level, the TRV will automatically close down the flow of hot water to the radiator. This will help to prevent the room from overheating.

How to set a TRV

TRVs are typically numbered from 0 to 5, with each number corresponding to a different temperature range. The higher the number, the warmer the room will be.

• 0: Frost protection
• 1: 10°C
• 2: 15°C
• 3: 20°C
• 4: 25°C
• 5: 30°C

Once you have set the desired temperature for the room, you should leave the TRV alone. Turning the TRV up to a higher setting will not make the room heat up any faster. It will simply use more energy.

Where to place a TRV

TRVs need a free flow of air to sense the temperature, so they must not be covered by curtains or blocked by furniture.

How to use a TRV in conjunction with a room thermostat

A room thermostat is used to control the overall temperature of your home. It works by sending a signal to your boiler, which tells the boiler when to turn on and off.

If you have a room thermostat, you should not normally need to use a TRV in the room with the thermostat. This is because the room thermostat will already be controlling the temperature of that room. However, if you do have a TRV in the room with the thermostat, you should keep the TRV on the maximum setting and adjust the room thermostat as explained in the instructions.

Benefits of using TRVs

Using TRVs can help you to save energy and money. This is because they will only allow the radiators to heat up to the desired temperature, which will prevent you from wasting energy.

In addition, TRVs can help to improve your comfort levels by providing you with more control over the temperature of each room in your home.

Conclusion

For more information on the thermostatic radiator valves (TRV) that we stock, please visit here.

A Comprehensive Guide to Sizing Heating Expansion Vessels

The guide provided is to assist with the sizing of a Heating Vessel and we would always recommend if unsure then refer to the system manufacturers guidelines to correctly size the Expansion Vessel.

This chart is to be used when sizing a Heating Expansion Vessel and not for Potable Water Applications.

Heating expansion vessels are crucial components in maintaining the safety and efficiency of your heating system. To ensure optimal performance, it’s essential to select the right size for your expansion vessel. In this guide, we’ll walk you through the process of sizing heating expansion vessels and provide helpful tips to make an informed decision.

What is a Heating Expansion Vessel?

A heating expansion vessel, also known as an expansion tank, is a crucial component of a central heating system. Its primary purpose is to accommodate the expansion of water as it heats up and prevent potential damage to the system due to increased pressure. A properly sized expansion vessel ensures the system operates safely and efficiently.

Factors to Consider When Sizing Heating Expansion Vessels

1. System Volume – The total volume of water in your heating system is a significant factor when determining the size of your expansion vessel. To calculate the system volume, you’ll need to consider the capacity of the boiler, radiators, pipework, and any other components that may contain water. Accurate system volume measurement is essential for selecting the right expansion vessel.

2. Maximum Operating Pressure – Each heating system has a maximum operating pressure, which is the highest pressure it can safely withstand. This value is typically provided by the boiler manufacturer. It’s crucial to ensure that the expansion vessel’s capacity matches or exceeds the maximum operating pressure to prevent system damage or failure.

3. Initial System Pressure – The initial system pressure is the pressure of the heating system when it’s cold and not in operation. This value is typically between 1 and 1.5 bar. To ensure the expansion vessel functions correctly, it must accommodate the pressure increase as the system heats up.

4. Expansion Ratio – The expansion ratio is the amount of expansion the water undergoes when heated. Water expands by approximately 4% when heated from 10°C to 100°C. For central heating systems operating at lower temperatures (such as 70°C), the expansion ratio will be slightly lower. Accurate calculation of the expansion ratio is crucial for selecting the right vessel size.

The Formula for Sizing Heating Expansion Vessels

To calculate the required size of your expansion vessel, you can use the following formula:

Expansion Vessel Size = (System Volume x Expansion Ratio) / (Initial System Pressure – Maximum Operating Pressure)

By applying this formula, you can determine the ideal size for your heating expansion vessel. Keep in mind that it’s always better to choose a slightly larger vessel than the calculated value to ensure adequate capacity.

Conclusion

Sizing a heating expansion vessel correctly is essential for the safety and efficiency of your central heating system. By considering factors like system volume, maximum operating pressure, initial system pressure, and expansion ratio, you can confidently choose the right expansion vessel for your needs. Use the provided formula to calculate the ideal size and consult with professionals if you need further guidance.

What Is a Motorised Zone Valve?

A Motorised Zone Valve is a type of valve used in HVAC (Heating, Ventilation and Air Conditioning) systems which regulates the flow of water or steam in different zones of a building. The valve is typically installed in the piping system and is controlled by an electric motor.

The valve has a movable disk or ball that can be rotated to control the flow of water or steam. The electric motor is connected to the valve and can be controlled by a thermostat or other temperature control system to open or close the valve as needed to maintain the desired temperature in each zone.

Motorised zone valves are commonly used in residential homes with separate heating areas for different floors, or commercial buildings with different HVAC zones for different departments or floors. They are also used in radiant heating systems (where heat is supplied directly to the floor or panels in the wall or ceiling of a building).

Please find below several frequently asked questions regarding motorised zone valves:

How Much Does a Motorised Zone Valve Cost?

If you are in the market for a motorised zone valve, we highly recommend Honeywell as the manufacturer. The zone valves we stock start from £84.97. Find out more information here.

Are Zone Valves Interchangeable?

Whether motorised zone valves are interchangeable depends on a few factors, including the manufacturer, the type of valve, and the specific model.

Some manufacturers offer interchangeable parts for their zone valves, which allows for greater flexibility in installation and repair. In these cases, you may be able to replace a faulty zone valve with a compatible model from the same manufacturer without having to make any significant modifications to your HVAC system.

However, it’s important to note that not all motorised zone valves are interchangeable. Different manufacturers use different valve designs and specifications, so you’ll need to check the compatibility of any replacement valve before making a purchase. It’s also important to ensure that the replacement valve is the same size and type as the original valve, and that it’s compatible with your HVAC system’s voltage and control systems.

If you’re not sure whether a motorised zone valve is interchangeable with your existing valve, it’s best to consult with a qualified HVAC technician. They can help you select the right replacement valve and ensure that it’s installed properly for optimal performance and safety.

Why Is My Motorised Zone Valve Buzzing?

There are several possible reasons why your motorised zone valve is buzzing:

• Electrical issues: One of the most common reasons for a buzzing motorised zone valve is an electrical issue. This could be caused by a loose wire, a faulty transformer, or a faulty control board. If the electrical components of the valve are not functioning properly, it can cause the motor to vibrate and create a buzzing sound.
• Dirt or debris: Over time, dirt and debris can accumulate in the valve, causing it to become clogged. This can interfere with the movement of the valve and cause it to vibrate or buzz.
• Mechanical issues: If the valve is old or has been subjected to heavy use, it may develop mechanical problems that can cause it to buzz. This could be caused by worn or damaged gears, a faulty motor, or other mechanical issues.
• Low voltage: If the valve is not receiving enough voltage, it may not operate properly and may emit a buzzing sound. This can be caused by a faulty transformer or other electrical issues.

If your motorised zone valve is buzzing, it’s important to have it inspected by a qualified HVAC technician. They can diagnose the problem and make the necessary repairs to ensure that your valve is functioning properly.

How To Fit a Motorised Zone Valve?

Fitting a motorised zone valve requires some knowledge of plumbing and electrical systems, so if you’re not comfortable with these tasks, it’s best to hire a qualified HVAC technician to do the job. Here are the general steps involved in fitting a motorised zone valve:

1. Turn off the power supply to the HVAC system to prevent electrical shock.
2. Identify the location in the piping system where the valve will be installed. This should be in the return line of the zone being controlled, downstream of the heating device and upstream of any check valve.
3. Shut off the water supply to the zone and drain the water from the pipes.
4. Cut into the pipe at the chosen location and install the valve according to the manufacturer’s instructions. Be sure to install the valve with the correct flow direction.
5. Connect the wiring to the valve according to the manufacturer’s instructions. Typically, the wiring will involve connecting the valve to a transformer and control panel.
6. Test the valve to ensure that it is functioning properly. Turn on the power supply and test the valve by operating the control system.
7. Once you have confirmed that the valve is functioning correctly, turn the water supply back on and check for leaks.

Keep in mind that the specific steps involved in fitting a motorised zone valve can vary depending on the manufacturer and model of the valve, as well as the design of your HVAC system. Be sure to consult the manufacturer’s instructions and follow all recommended safety procedures when installing the valve. If you’re not confident in your ability to install the valve properly, it’s best to seek the assistance of a qualified HVAC technician.

How To Bleed a Radiator

Bleeding a radiator is the process of releasing any trapped air from the system, which can prevent your radiator from heating up properly. To bleed a radiator, you will need a few tools:

1. A radiator key or a flat screwdriver (depending on the type of valve on your radiator)
2. A towel or cloth to catch any water that may drip out

Here are the steps to bleed a radiator:

1. Turn off your heating system to prevent any hot water from flowing through the radiator.
2. Locate the valve at the top of the radiator. It will usually be located on one of the sides and will be a small square or hexagonal nut.
3. Place the towel or cloth under the valve to catch any water that may drip out.
4. Insert the radiator key or flat screwdriver into the valve and turn it anti-clockwise. You should hear a hissing sound as the air is released. Keep turning until water starts to flow out of the valve.
5. Once water starts to flow out, quickly turn the valve clockwise to close it again. Be careful not to over-tighten the valve as this could damage it.
6. Wipe any water that may have dripped out of the valve with the towel or cloth.
7. Turn your heating system back on and check that the radiator is heating up properly.
8. Repeat this process for each radiator in your home, starting with the one located furthest from the boiler and working your way back towards it. This will ensure that all of the air is removed from the system.

How Much Can Bleeding a Radiator Save?

How much bleeding a radiator can save will depend on a number of factors, including the size of your home, the number of radiators you have, and how often you bleed them. However, some estimates suggest that bleeding your radiators regularly could save you up to 10% on your energy bills.

For example, if your annual heating bill is £2,500 (a 3-bedroom home typical usage reported by British Gas), bleeding your radiators could save you up to £250 per year. While this may not seem like a significant amount, over time, the savings can add up.

In addition to reducing your energy bills, bleeding your radiators can also help to prolong the life of your heating system, as it reduces the strain on the system and prevents corrosion in the radiators. So, while bleeding your radiators may seem like a small task, it can have a big impact on your home’s energy efficiency and your overall heating costs.

Aladdin Autovent Automatic Radiator Bleeders

Aladdin Autovents automatically bleed air and improve efficiency of radiators, heating systems and underfloor heating networks.

• No need to manually bleed radiators.
• Keeps radiators and heating systems fully heat generating and efficient.
• No gas = reduced corrosion = extended component life.
• Drains air from underfloor heating networks.
• Keeps the radiators hot to the top.
• Save heating and energy costs by optimising radiator efficiency.
• Avoids tenants calling out service engineers just to vent radiators.

What Is a Backflow Prevention Device?

An introduction to Fluid Categories and Backflow Prevention Types to ensure the safe delivery of wholsome water

Fluid category 1

Wholesome water supplied by a water undertaker and complying with the requirements of regulations made under section 67 of the Water Industry Act 1991(1).

Fluid category 2

Water in fluid category 1 whose aesthetic quality is impaired owing to–

(a)a change in its temperature, or

(b)the presence of substances or organisms causing a change in its taste, odour or appearance,

including water in a hot water distribution system.

Fluid category 3

Fluid which represents a slight health hazard because of the concentration of substances of low toxicity, including any fluid which contains–

(a)ethylene glycol, copper sulphate solution or similar chemical additives, or

(b)sodium hypochlorite (chloros and common disinfectants).

Fluid category 4

Fluid which represents a significant health hazard because of the concentration of toxic substances, including any fluid which contains–

(a)chemical, carcinogenic substances or pesticides (including insecticides and herbicides), or

(b)environmental organisms of potential health significance.

Fluid category 5

Fluid representing a serious health hazard because of the concentration of pathogenic organisms, radioactive or very toxic substances, including any fluid which contains–

(a)faecal material or other human waste;

(b)butchery or other animal waste; or

(c)pathogens from any other source.

Backflow Prevention Device

Type BA – Verifiable backflow preventer with reduced pressure zone

Type CA – Non-verifiable disconnector with different pressure zones

Type DA – Anti-vacuum valve (or vacuum breaker)

Type DB – Pipe interrupter with atmospheric vent and moving element

Type DUK1 – Anti-vacuum valve combined with a single check valve

Type EA – Verifiable single check valve

Type EB – Non-verifiable single check valve

Type EC – Verifiable double check valve

Type ED – Non-verifiable double check valve

Type HA – Hose union back flow preventer

Type HC – Diverter with automatic return

Type HUK1 – Hose union tap incorporating a double check valve 

Type LA – Pressurised air inlet valve

Type LB – Pressurised air inlet valve combined with a check valve downstream

Please follow the link below to view our available Backflow Prevention Devices

 Backflow Prevention Devices

More Information

A backflow prevention device is a mechanical valve or assembly designed to prevent the undesirable reversal of water flow in a plumbing or water supply system. This helps to protect potable water sources from contamination or pollution caused by backflow, which occurs when water flows in the opposite direction of its intended path due to changes in pressure or other factors.

Backflow can introduce contaminants from non-potable sources, like industrial fluids or wastewater, into the drinking water supply, posing serious health risks. Backflow prevention devices are crucial in safeguarding water quality and public health.

There are several types of backflow prevention devices, including:

1. Air gap: The simplest form of backflow prevention, an air gap is a physical separation between the potable water supply and a potential source of contamination, ensuring that contaminants cannot reach the potable water.

2. Atmospheric vacuum breaker (AVB): A mechanical device that uses atmospheric pressure to prevent backflow. It is typically installed on hose bibs or faucets to protect against back-siphonage.

3. Pressure vacuum breaker (PVB): A device that incorporates both a check valve and an air inlet valve, designed to protect against back-siphonage in low hazard situations.

4. Double check valve assembly (DCVA): A backflow prevention device consisting of two independent check valves, typically used in low to moderate hazard situations.

5. Reduced pressure zone (RPZ) assembly: A more complex device with two independent check valves and a pressure relief valve, designed to protect against both back-siphonage and backpressure in moderate to high hazard situations.

Backflow prevention devices are installed in various settings, including residential, commercial, and industrial applications, and are subject to local building codes and regulations. Regular inspection and maintenance are essential to ensure that these devices function properly and continue to protect water supplies.

Guide To Servicing an Expansion Vessel on an Unvented Cylinder

An expansion vessel, also known as an expansion tank, is an essential component of an unvented cylinder system. It plays a critical role in maintaining system pressure by accommodating the expansion of water as it heats up. Regular servicing of the expansion vessel is necessary to ensure the proper functioning of the unvented cylinder system. This guide will provide you with step-by-step instructions on how to service an expansion vessel on an unvented cylinder.

Required Tools and Materials:

1. Replacement diaphragm (if necessary)
2. Pressure gauge
3. Schrader valve core tool
4. Tire inflator with a pressure gauge
5. Adjustable spanner
6. Safety goggles
7. Gloves

Safety Precautions:

Before you begin, ensure that you have switched off the power supply to the boiler or immersion heater and isolated the water supply to the unvented cylinder. Always wear safety goggles and gloves to protect yourself from potential hazards.

Step-by-Step Guide:

Depressurise the system:

1. Close the mains water supply valve to the unvented cylinder.

2. Open a hot water tap in the property to drain the hot water from the system and release pressure.

Locate the expansion vessel:

Expansion vessels are typically located near the unvented cylinder or attached to it. In some cases, it may be installed remotely.

Check the pre-charge pressure:

1. Remove the dust cap from the Schrader valve on the expansion vessel.

2. Attach the pressure gauge to the Schrader valve.

3. Record the pre-charge pressure reading.

4. Compare the recorded pressure with the manufacturer’s recommended pre-charge pressure. If the pressure is lower than the recommended value, proceed to step 4.

Adjust the pre-charge pressure:

1. Use the tire inflator with a pressure gauge to inflate the expansion vessel to the manufacturer’s recommended pre-charge pressure.

2. Re-check the pressure with the pressure gauge to ensure it is correct.

3. If the vessel loses pressure quickly, there may be a leak in the diaphragm. In this case, proceed to step 5.

Replace the diaphragm (if necessary):

1. Depressurise the expansion vessel by pressing the Schrader valve core tool on the valve.

2. Unscrew and remove the vessel from the unvented cylinder system or its bracket.

3. Open the expansion vessel and remove the damaged diaphragm.

4. Install the new diaphragm, ensuring it is properly seated.

5. Reassemble the expansion vessel, ensuring all connections are tightened and secure.

Reinstall and pressurise the expansion vessel:

1. Reattach the expansion vessel to the unvented cylinder system or its bracket.

2. Inflate the expansion vessel to the manufacturer’s recommended pre-charge pressure using the tire inflator with a pressure gauge.

3. Re-check the pressure with the pressure gauge to ensure it is correct.

4. Replace the dust cap on the Schrader valve.

Restore the system:

1. Close the hot water tap that was opened in step 1.

2. Open the mains water supply valve to the unvented cylinder.

3. Switch the power supply back on to the boiler or immersion heater.

Test the system:

1. Run hot water from a tap to ensure proper flow and temperature.

2. Check for any leaks around the expansion vessel and its connections.

Conclusion:

Servicing an expansion vessel on an unvented cylinder is crucial for maintaining the system’s efficiency and safety. Regularly monitoring and adjusting the pre-charge pressure, as well as replacing the diaphragm when necessary, will help ensure the longevity of your unvented cylinder system. Always consult the manufacturer’s guidelines for specific instructions and recommendations for your particular system. By following this guide and adhering to safety precautions, you can effectively service your expansion vessel and keep your unvented cylinder system running smoothly.

A Short Guide To Sizing a Potable Expansion Vessel

A Short guide to sizing a Potable Expansion Vessel on an Unvented Mains Pressure System. 

The guide below has been calculated to give an estimated size of Expansion Vessel required for a mains fed potable system, this does not take in all fluctuations in systems but will give an idea of size.

For an exact sizing you will require System Capacity (Litres), Pressure Reducing Valve Pressure (Bar), PRessure Relief Valve Setting (Bar) and Maximum Working Temperature of the system (DegC) 

For more information on our Potable Expansion Vessels click the link below:

Potable Expansion Vessels

How to Recharge a Depleted Air Gap in an Unvented Cylinder

Cylinders with Air Gaps have a volume of air in the top of the cylinder which is designed to take the expansion of the water when heat is added. If the Air Gap reduces then leaks can occur from safety relief valves. This does not automatically mean there is a fault within the system it may just need the Air Gap reinstating. The procedure to reinstate the Air Gap is very simple, please follow the guidelines below: 

1: Turn off the mains supply to the Unvented Cylinder

2: Open the nearest Hot tap to the Unvented Cylinder

3: Hold open the Temperature and Pressure Relief Valve on the Cylinder to discharge water via the Tundish, when the gurgling noise has stopped and no more water is flowing through the Tundish close the Temperature & Pressure Relief Valve

4: Ensure the Temperature & Pressure Relief Valve is closed, close the hot tap and turn back on the mains to the Unvented Cylinder. At this point the Air Gap will reinstate itself as the system fills

Note:

If you have completed the above and water is still passing from the Safety Relief Valve then you may have an issue with the Safety Relief Valve, contact a competent plumber to investigate. (If a Relief Valve is dripping for a long period of time wiring can form in the brass and a small amount of the seat will erode and not seal).