Many homes now receive their heating and hot water through “heat-only” central heating systems that include an unvented water cylinder.
Instead of a separate cold water tank, the unvented water cylinder is fed directly from the mains water supply, guaranteeing you a regular flow of water provided your home benefits from good mains water pressure.
Unvented water cylinders are self-contained, so can be installed in many places in your home, taking into account where it would be most practical, but also as inconspicuous as possible.
These benefits are enjoyed in many thousands of homes, but there are steps you should take to keep your hot water cylinder working efficiently and reliably. This article answers the most common questions about your unvented water cylinder, so you have a good idea of what to do to keep it working properly and efficiently, but also what to do if you discover a problem.
What is an Unvented Hot Water System?
An unvented hot water system provides hot water, at high pressure, making it suitable for all uses around your home. It can produce hot water at a much higher flow rate than traditional open vented systems, which rely on gravity and the height of the water tank.
Additionally, the cold water outlets are also supplied directly from the mains, sending water at suitable pressure throughout the unvented central heating system. An unvented system supplies hot and cold water at roughly the same pressure as your garden tap.
An unvented water cylinder stores domestic hot water ready to be used when you turn on a hot water outlet. The cylinder is connected directly to the mains water supply and can be heated by a system boiler (indirectly) or by an immersion heater (directly).
Some indirectly heated unvented water cylinders use solar power, reducing the user’s impact on the environment and lowering their energy bills.
Why is my hot water pressure low?
Your hot water pressure can reduce over time, which may be due to a number of possible causes. You could have a blocked inlet filter, or if your system is older, the PRV (Pressure Reducing Valve) cartridge may have failed, and be restricting the flow.
You might notice this problem more the higher the tap is in the house – so a shower in the loft may suffer from this more than one on a ground floor or basement.
Why is my hot water cloudy?
Heating mains water under pressure can result in tiny carbon dioxide bubbles forming. This is caused by calcium bi-carbonate in the water changing to calcium carbonate. When you draw off water under normal atmospheric pressure, these bubbles are released, making the water look cloudy.
It is completely harmless and normal, and may be more noticeable in the winter months when the incoming water is cooler. Just check that the water clears quite quickly and no sediment remains, and you’ll have nothing to worry about.
What should I do if I discover a leak in my unvented hot water cylinder?
Leaks do occur in unvented hot water cylinders, often due to the high levels of wear and tear sustained by many of their parts. First, you should check the temperature of the leaking water, as establishing this can rule out some possible causes for the problem.
You should then turn off the water supply to the unvented water cylinder, which is usually done by turning off the handle on the pipe running into the bottom of the cylinder.
Then you should immediately call a Gas Safe registered engineer.
Can I fix a leak in my unvented hot water cylinder myself?
Definitely not. Because your hot water system channels water through at high pressure, you risk seriously injuring yourself!
Unvented water cylinder repairs can only be carried out by a technician with a G3 certification.
This certification forms part of the Building Regulations, and shows that the holder has been trained to work on pressurised water systems, with specific focus on correct location, fitting of pressure and temperature controls, and venting of an unvented water cylinder.
RJ Martindale and BHE heating and plumbing engineers are trained and qualified to G3 standards and are able to install, service and maintain unvented water cylinders.
If you have unvented water cylinder repairs carried out by someone without this accreditation, your property could be made unsafe, or be damaged. It is also very likely that your home insurance won’t be valid should a system failure result.
My immersion heater in my unvented water cylinder isn’t heating my water. What should I do?
You need to call a Gas Safe-registered engineer, who will be able to test the electricity supply to your unvented water cylinder’s immersion heater.
If your immersion heater needs to be replaced, the unvented water cylinder will need to be drained.
If necessary, your heating engineer will remove the immersion heater and complete a continuity fault test on the immersion and the thermostat to make sure they are reading correctly, using a voltmeter or multimeter.
If you are having problems with your hot water supply, RJ Martindale is your local expert in hot water cylinder installation and repairs. Our heating engineers cover the Bolton, Horwich, Chorley and Preston areas, and our fast response from staff with many years’ experience of servicing and repairing all makes and ages of boilers gives you the reassurance you need that your home’s heating and hot water are in safe hands.
How can I avoid potential expense on unvented hot water cylinder repairs?
An unforeseen problem with your unvented hot water cylinder could be costly and inconvenient. You can avoid finding yourself in this situation by taking out a boiler cover policy.
This entitles you to annual checks on the operation of your boiler, unvented water cylinder and heating system. These can detect potential problems early, and will ensure that your heating and hot water continues to operate efficiently, as well as satisfying the terms of any warranty on your boiler and unvented water cylinder.
Homecare boiler servicing plans start from just £9 a month with RJ Martindale and BHE.
Install unvented water cylinders with RJ Martindale’s Gas Safe Registered team in Bolton, Horwich, Chorley & Preston
Installation of unvented water cylinders should be carried out by a G3-accredited engineer, ensuring your new water cylinder, boiler and central heating system operates to its best. RJ Martindale’s installation engineers throughout the North West are Gas Safe Registered and G3 qualified, giving you the reassurance you need that your home’s in safe hands.
Installing unvented water cylinders, boilers and central heating systems in Bolton, Horwich, Chorley and Preston, we’re one of the North West’s most trusted water cylinder, boiler and central heating installation organisations, protecting homes, families and investments with fully-qualified, reliable and experienced gas boiler services.
With hundreds of five-star Google reviews for our work, we take the heat out of finding the right type of water cylinder, and the answers to your complete water and home heating installation and maintenance needs, across the Bolton, Horwich, Chorley and Preston areas.
Time to install your new unvented water cylinder? Book a FREE survey with RJ Martindale. We’ll recommend unvented water cylinder models to suit your budget and your household’s needs from a range of leading manufacturers, before installing your new unvented water cylinder promptly.