How to prepare your boiler for the winter

It sounds counterintuitive but the best time to service a boiler and make it ready for winter is during summer, if not late spring.

This allows for any fixes, repairs and replacements needed, and so you can avoid the winter-time rush for boiler engineers. Crucially, you should ensure you’re not left without hot water or heating during the coldest months. Here are our top tips to help you get the most from your boiler for the winter.

Boiler tips for winter.

Arrange your annual boiler service.

An annual boiler service checks the well-being of your boiler and is a major step towards ensuring your central heating and hot water system are working as efficiently as possible.

It will highlight any issues causing the boiler to work overtime, drive up bills and risk more costly repairs or even failures later on that might leave you without heat and hot water.

Swale Heating services cost as little as £90 - for more information on our boiler service plans, please here.

Test run your central heating.

Don’t fall into the trap of turning your heating off after the winter and leaving it until the season comes around again.

Test run your heating briefly during the warmer weather and certainly well before you really need it again. This helps the boiler itself and the entire central heating system – from the thermostat to the flow of water running through your radiators – potentially highlighting any issues before cold weather really hits.

Bleed your radiators.

Apart from a healthy boiler, an effective central heating system needs radiators in tip top condition too – so bleed these regularly.

Use a radiator key to open the bleed valve (usually located at the top of your radiator) until you hear a hissing sound, which is air escaping, but keep a rag handy for the moment when water starts to follow - your signal to close the valve again.

This process helps remove excess air that may impact the efficiency of the system and lead to lukewarm radiators.

If you don’t hear the release of air or water this could be due to the pressure of the boiler. Look for a pressure gauge, or something similar, on the boiler to help validate this.

If you need any checks or repairs, make sure they are always carried out by a Gas Safe registered engineer: Swale Heating operates a reliable and Gas Safe registered team to help keep you warm all winter - find out here.

Check your thermostat.

Faulty thermostats can lead to rooms being too hot or too cold. Common signs here include:

  • Room too hot or too cold for the chosen setting
  • Boiler isn’t ‘kicking in’
  • Radiators fail to warm up

Firstly, make sure that your thermostat is switched on and that you’re not accidently allowing it to override your settings via the override option. You could also check the thermostat’s battery if applicable.

You can also slowly increase the temperature of your central heating. By doing this, you’ll be able to hear a clicking sound as well as noise from the boiler. If this isn’t happening, this could be a sign that your thermostat isn’t sending the correct signals to your boiler. If a fault in the thermostat continues, seek the advice of a Gas Safe certified engineer – we can help here .


This is essentially a spring clean for your central heating using a pressurised powerflush unit to push water around your system to clear debris, limescale, sludge and blockages that may be hindering performance of your boiler and central heating system.

This will help improve heat distribution, efficiency and energy consumption, ultimately reducing energy costs. If you think your boiler could benefit from a powerflush, please book here.

Clean your boiler.

Cleaning your boiler and its surrounding area can help reduce the risk of a breakdown, as well as removing any blockages that may affect boiler efficiency.

Start by ensuring the vents aren’t blocked with dust and debris, filters are in place and there are no other obstructions preventing smooth air flow. This is a simple and quick way to prolong boiler life and avoid risk of breakdown. We would recommend you hire an expert to clean the boiler itself.

Don’t forget the pipes.

Make sure that all your pipes are in top working condition by having a powerflush (see earlier) or system clean to remove anything preventing a smooth flow of water throughout your system.

Additionally, check your pipes in vulnerable areas are well insulated. This will prevent issues such as freezing or losing valuable heat and energy.

Install a heating system filter.

Over time, dirt, chalk, sludge and other grime can build up within your boiler and central heating system. As we’ve already said, a consistent, undisturbed flow of water must flow through your system to optimise efficiency.

But you can help prevent any build-up in the first place by installing a heating system filter. It will aid efficiency and prolong the life of your boiler and its components, plus save you money and energy consumption in the long run.

Be vigilant.

Keep watch on your boiler, particularly any strange noises it makes, and on how your radiators feel, making sure they warm a room and aren’t left feeling cold in places.

Other indicators that your boiler may not be working effectively include:

  • Black stains around or on the boiler
  • The flame is a different colour to blue
  • The pilot light keeps going out
  • It takes longer than normal for the system to heat up

If you notice any of these issues, seek the assistance and advice of a Gas Safe registered engineer as soon as possible. The Swale Heating team is always on hand to help – contact us to find the best service for you.

Fix anything that is wrong.

It may seem obvious, but don’t delay getting anything fixed. In addition to adding to energy bills, you don’t want to damage your central heating system or boiler any further and incur potentially even more expensive and disruptive solutions, particularly in winter.

Swale Heating can help advise and assist you with any boiler fixes and repairs. We offer payment plans so you can be safe in the knowledge that you are covered if any issues arise.

Why it is important to check your boiler before the winter?

Stay ahead of the game and make sure you get an annual boiler service booked in during the spring or summer, giving you plenty of time to settle repairs, replacements and fixes.

Frequently asked questions about winter boiler preparation.

Here at Swale Heating, we have a team of experts on hand offering knowledge and support on these difficult topics. Based on their experience, here are some frequent questions and their best answers:

What temperature should I set my boiler at in winter?

This depends mostly on personal preference but setting your thermostat at around 20 degrees will get the most from your heating and energy spend. Your house will warm to a suitable temperature, but higher than 20 degrees will likely deliver less benefit for more expense.

How many hours should I turn my heating on per day?

On average, UK homes are heated for around eight hours a day, but you may be surprised to learn this could be excessive.

Personal preference plays a big part and all properties are different, with some needing more time to warm up than others, which is why some personal detective work is needed to optimise heating and hot water needs and balance against energy cost.

It’s good advice to consider a lower thermostat setting, but give the heating a consistent run throughout the day when you are home, instead of short bursts or leaving it on all day. Make use of the timer and thermostat to customise your heating needs.

Can I leave my boiler on continuously?

Yes. But this will be reflected in your bills. If you are unsure of the best boiler settings, seek the advice of a professional at your next boiler service.

When is it time for a boiler upgrade?

There is no clear answer: it can be the boiler’s age, its condition or what it must do.

Fortunately, some 50 years’ experience means that Swale Heating can give sound advice and do all the hard work, so you don’t have to. 

Simply get in touch and tell us about your current heating system and your availability. Rely on us to keep you warm this winter. Click here to complete your free no-obligation online quotation.

Why choose Swale Heating?

We were founded in 1972 to focus on top quality installation with follow-up maintenance to the same standard.

Swale Heating is now one of Kent's largest installers of boilers and heating systems, completing thousands of installations each year, and keeping homes safe and warm, via our maintenance and repair services.

We understand that the failure of your heating system can leave you feeling anxious, which is why we're available 24 hours a day, 365 days a year. You can find out more about our boiler cover plans and use our online portal to book your repair or annual service. If you would like a quote for a new boiler, click here.