Frequently Asked Questions

As a family-run business of over 40 years, Newark Cylinders has a wealth of knowledge when it comes to answering commonly asked questions on hot water cylinders, thermal stores, buffer vessels, and more.

Table of Contents

How can I find out more about the HG Series Cylinder designed by Heat Geek?

copper header tank image

What is a Header Tank?

“Header tank” is a term usually used for the cold water storage tank, positioned at the highest point of a vented, primary heating system.

The term “feed & expansion tank” is also commonly used for the cold water storage tank. However, this is usually for tanks within secondary hot water systems, rather than heating systems.

In both cases, the tanks accept cold mains water via a float valve, fill and keep their systems topped up with water, and absorb additional water volume from their systems when it expands through heating.

Which is better – a copper or stainless steel hot water cylinder?

Both copper and stainless steel have their own advantages.

Our comparison takes into account several attributes including Antibacterial Properties, Heat Conductivity, Affordability, Flexibility, and Recyclability.

Please see our comparison:

What is a buffer tank/buffer vessel?

Buffer Vessel Collection Newark Cylinders

Buffer Vessels only hold non-potable, primary water and don’t supply any hot water to taps or showers.

They can serve many different purposes within heating systems, including:

  1. Acting as a central point of heat storage generated by the property’s heat sources.

    This may include storing heat generated by heat sources which aren’t always available, such as solar and solid fuel burners. Once the heat has been stored, it can then be drawn off for heating purposes, on demand, throughout the day.

  2. Adding volume to a system

    Some heat sources require a system to have a minimum volume at all times, to prevent cycling of the heat source in the event that some parts of the system are isolated from the rest.

  3. Adding controllability to an otherwise uncontrollable heat source

    A buffer vessel can be utilised to store heat from an uncontrollable heat source and then extracted on demand, to heat a cylinder which wouldn’t usually accept heat from an uncontrollable heat source (like an unvented cylinder).

Our service doesn’t include recommending the correct product designs for our customers’ jobs, so the effectiveness of their use within a system should, therefore, be determined by a competent installer.

What is a Thermal Store and how do they work?

Thermal Stores are designed to store large quantities of heat energy until required efficiently.

The key difference between a Thermal Store and a standard hot water cylinder is that the Thermal Store provides hot water to your taps and showers, via a high surface area coil. High-pressure water from the cold main enters the bottom of this coil and absorbs heat from the surrounding water as it goes.

By the time the water reaches the top of the coil, its temperature will have increased substantially, so it passes through a thermostatic mixer valve to ensure it’s delivered to your taps at a comfortable 55°C. Assuming the store temperature is maintained at around 70°C, an unlimited amount of hot water will potentially be available.

Thermal Stores excel in versatility; a variety of different connections and coils can be incorporated for whatever combination of heat sources and points of use you have.

To find out more about how thermal stores work, please read our article.

What is a thermal mixer?

“Thermal mixer” is a partial abbreviation of “Thermostatic Mixer Valve” and describes any valve whose job it is to regulate the temperature of the water that is being delivered to the property’s taps and showers.

It does this thermostatically, so as hot water enters the valve, it will detect the temperature of that water, and adjust itself to let in the amount of cold water that would be necessary to reduce that temperature to the desired level.

We supply mixer valves with all of our thermal stores, as the water tends to be relatively hot as it leaves these types of cylinders, so reducing that is necessary to ensure that no one gets scalded.

Why should I standardise my bespoke cylinder designs?

We usually work directly with companies who have particular requirements to meet, innovative ideas to incorporate, or restrictive obstacles to overcome. But in many of these cases, we then work with those companies to standardise that bespoke design into their own exclusive range, as it makes them optimal for the majority of their installations.

Compared to designing something bespoke each time, this helps to minimise everyone’s admin costs, the savings from which can passed on, keeping everyone in the supply chain competitively priced.

Horizontal cylinder diagram

What are horizontal cylinders?

Contrary to semi-popular belief, they are not just vertical cylinders laid down. Horizontal cylinders are specially designed cylinders whose features are positioned in such a way that they can be laid down and still operate correctly.

Can I convert a vented cylinder to an unvented cylinder?

No, this is not possible without upgrading your entire system. While changing your system from a vented cylinder to an unvented system could be costly, having an unvented installation has the potential to be more cost-effective long term.

Can I retrofit a thermal store into my existing heating system?

Yes, in many cases, it is possible to retrofit a thermal store into an existing heating system. However, this process requires careful consideration of the system’s compatibility, size, and integration.

It’s recommended to consult with a heating system professional who can assess your current setup, evaluate the feasibility of retrofitting a thermal store, and provide guidance on the necessary modifications.

Retrofitting offers the advantage of enhanced energy efficiency and flexibility in managing various heat sources within your heating system.

horizontal cylinder image Newark Cylinderss

What is the difference between a calorifier and a hot water cylinder?

Technically none, as a Calorifier is just a more definitive name for a hot water cylinder. However, within this industry, the term “cylinder” is often used to loosely refer to any cylindrical water storage vessel, including Thermal Stores and Buffer Vessels.

“Calorifier” is, however, usually used to describe hot water cylinders which are for marine applications and large industrial applications, while “cylinder” is used more for domestic hot water (DHW) applications.

What is a combination cylinder?

combination cylinder image

A combination cylinder (often referred to by us as a “combi”) is the exact same principle as a vented cylinder, but its cold water tank is built onto the top of the hot water storage section (as opposed to being situated somewhere above, such as on a shelf or in a loft space).

They are designed as a space-saving unit, removing the need for a separate header tank.

What is an Immersion Heater?

Immersion heaters are electrical components that are inserted either from the top or side of a cylinder to efficiently heat water. This process closely resembles the way a kettle functions to heat water.

Due to their (usually) low power outputs though, it can take much longer for immersion heaters to heat a cylinder than it would if heat sources such as heat pumps or boilers were used.

View our range of Immersion Heaters.

What is the purpose of a pressure relief valve in a heating system?

A pressure relief valve is a crucial safety component in a heating system. Its primary purpose is to protect the system from overpressure conditions that could potentially lead to serious safety hazards. If the pressure within the system exceeds the recommended levels, the relief valve automatically releases excess pressure, preventing damage to the components and ensuring the safety of the entire heating system.

Regular maintenance and testing of the pressure relief valve are essential to ensure its proper functioning and to uphold the safety standards of your heating setup.

Where can I find manuals for your products?

You can find instruction manuals for our Aquinox Stainless Steel Unvented Hot Water System and POWERflow Unvented Hot Water System on our Downloads page.

If you require help with any of our other products, please contact us.

What size Hot Water Cylinder do I need for a family of 4?

It is advised that a cylinder should be installed to suit the maximum occupancy of the property, rather than how many people currently occupy it. This is because if you decide to move out, and a larger family moves in, the installed cylinder would meet their needs.

However, if you are planning on staying in the same property for a long period of time, it would be worth considering whether a smaller cylinder would be more appropriate. An unnecessarily larger cylinder would result in higher, and unwanted, running costs.

The Hot Water Association can assist you with their hot water calculator.

They suggest a household of 4 people who use the average amount of hot water requires an 80-litre indirect or a 140-litre indirect cylinder.

How Do I Maintain My Heating and Hot Water System?

Various factors can assist you with optimising the efficiency of your heating and hot water system.

You can read about these here.

Why are there no Unvented cylinders on the online shop?

Because Unvented cylinders by nature operate at high pressure, it can be dangerous to the occupants if an unvented cylinder is incorrectly installed and therefore requires an Unvented G3 Certificate.

If you are a certified installer, you can purchase an unvented cylinder directly through ourselves by getting in touch by email or phone.

Where do your cylinders come from?

All of our cylinders are manufactured in-house, which allows us to offer greater flexibility in designs and options for our cylinders.

What is Economy 7?

Economy 7 (or ‘ eco 7’) is an electricity tariff offering cheaper rates for off-peak hours and more expensive rates during peak hours.

When is Economy 7 hours?

The off-peak duration is for 7 hours, and according to Ofgem, your energy supplier will specify when this 7-hour period is. Although it is often between midnight and 7:00 am.

Are site visits a part of your service?

We are not insured to work anywhere besides our own premises. Determining the correct product for your job is also not part of our service, so we rely on installers to survey your property’s requirements. They can then provide the necessary information to us. Therefore, we are unable to provide on-site assistance.

Do you offer a trade discount?

We do offer trade discounts and credit accounts, however, these are subject to approval after repeat business.

I live locally, can I collect?

Yes, when you are ready to checkout you can enter the discount code COLLECT to remove the carriage charge. We will then let you know when your unit is ready for collection.

Find us on what3words:

Need More Help?

If we haven’t answered your question above, please don’t hesitate to contact us.

Can't find what you're looking for? We're here to help.

If you can't find what you're looking for please let us know your email and query and we'll be happy to help. 

If you would like us to give you a call back, please provide your contact telephone and we will be in touch.

    Name Email Telephone (Optional) Message