Your central heating system can be likened to a car in the sense that it contains moving parts that need to be regularly serviced and maintained in order to ensure smooth running.

Ignore or neglect the maintenance on your car and after a while you're likely find yourself stuck on the hard shoulder of a busy motorway.

Service it regularly, however, you'll ensure that your driving holiday to the south of France will go off without any hiccups.

You can look at maintenance of your central heating in exactly the same way.

Simply swap the side of the motorway for a broken boiler in the middle of a cold snap in January and the plain-sailing drive to the south of France with a home that remains nice and cosy throughout the winter.

In this article we'll look at why summer is a great time to perform that important heating maintenance and what the most essential jobs are.

  • Plumbers aren't as busy in the summer
  • Bleed your radiators
  • Top up your inhibitor
  • Turn up your TRVs
  • Turn on your heating (briefly)

Plumbers aren't as busy in the summer

A man smoking and relaxing

This is definitely not to suggest that, during the summer, all plumbers are sat around in beer gardens waiting for their phones to ring.*

However, it's true that plumbers are more readily available to carry out tasks they might not be so free to do in winter.

This is mainly to do with the fact that plumbers spend a lot of the colder months rushing from emergency to emergency. Broken boilers that leave a family without heating or burst pipes causing flooding in an elderly person's home etc.

In the summer, emergencies like this are fewer and farther between, which means a plumber can probably fit you in very quickly after you call them to request a visit and a quote.

Taking advantage of plumbers' availability means you may also be able to negotiate a better price than you would if you were desperate for help n the middle of winter.

By getting things done in the summer, you're far less likely to experience problems in the winter when your central heating system is put under the most strain.

* We are.

Bleed your radiators

Radiator key bleeding radiator

If you decide against getting in a plumber and want to tackle some tasks yourself, then bleeding your radiators is one of the easiest and most important jobs you can do.

Summer is a good time to do this because you probably aren't using your heating and you won't have to worry about hot radiators cooling down before you can bleed them.

If you've noticed in the winter or in the spring that some of your radiators weren't getting as hot as they could be, or they were hot at the bottom but not at the top, it can often be solved by bleeding them.

Bleeding a radiator simply means letting the air out that may have got trapped at the top of the radiator over time.

Instead of the hot water flowing freely around the radiator, air may have got into the system and is preventing the hot water from heating the entire radiator.

You can see exactly how to bleed your radiator in the video below where Jimmy the qualified plumber takes you through the entire process step by step.

Top up your inhibitor

Chemical Inhibitor poured into a heated towel rail

While you're carrying out some summer maintenance, an important and often overlooked part of the process is topping up the levels of chemical inhibitor in your heating system.

If you have no idea what chemical inhibitor is, then it's likely your system needs to be topped up. Likewise, if you have no idea when chemical inhibitor was last added to your system, it's likely more needs to be put in.

To go back to the car analogy, chemical inhibitor is similar to the engine coolant/antifreeze that you put into your car. This stops the water in your car from overheating or freezing but it also helps ensure that the internal components of your engine do not get clogged with sediment or rust.

Inside your central heating system, water is constantly flowing around your pipework, radiators, boiler and heat pump. If left to it's own devices, the water will have a chemical reaction with the metal inside all these components, causing rust and corrosion.

Tiny shards of metal will flake off into your system, often coming to rest at the bottom of your radiators or narrowing the flow of water through your pipework.

Everything in your heating system will have to work harder and harder in order to keep hot water flowing to the right places, until the inevitable breakdown occurs, normally in winter when you need heating the most.

However, this internal corrosion can be virtually brought to a standstill by pouring chemical inhibitor into your system and ensuring that the levels are topped up once a year.

The inhibitor helps to stop the chemical reaction from occurring, reducing the corrosion and rusting that goes on inside your heating system. This will ensure that your heating system runs smoothly and efficiently and helps to prolong the life of all of the components involved.

To see the difference between a system with and without chemical inhibitor in it, please see the very informative comparison vide from Jimmy the plumber.

Turn on your TRVs

Thermostatic Radiator Valve

If you've got TRVs (thermostatic radiator valves) on some or all of your radiators, then it's important to pay attention to them during summer even if you aren't using your central heating.

TRVs react to the temperature in the room, so as the spring turns into summer and the temperature gets warmer, the TRVs will close themselves off as they are supposed to do.

However, what is likely to have happened just before you stop using your central heating is that you switched your TRVs down to low as less hot water is needed to heat the radiator. The higher summer temperatures will have kicked in and you will have switched of your central heating with the TRVs in the low position.

In theory this is the correct things to do, however in reality, what you might find when you come to use your heating again at the end of summer is that your TRVs have got stuck in the off position. This will mean that your radiators won't get hot and you or a plumber will need to free up the pin inside the valve.

A very easy way to avoid this inconvenience is to turn your TRVs to the 'Maximum' position and then switch off your heating. Your heating will be off so you won't be getting unnecessarily hot, but it means when you go to switch it back on in September your TRVs will be fully functional and won't be stuck shut.

Please fell free to watch our Ultimate Guide to TRVs with Jimmy the plumber in the video below.

Turn on your heating (briefly)

Smart thermostat

Because you aren't using your heating during the summer months, this recommendation could initially seem a bit counterproductive. Why would you want to switch on your heating when you least need it?

Actually, all you need to do about once every three or four weeks during the summer is remember to switch your central heating on for about 15 or 20 minutes.

Set your timer so that it comes on just after you've left the house for the day, so that the heat has time to dissipate by the time you return home.

By doing this, you'll help the components of your heating system to keep moving so that they are ready to leap back into action when the temperature drops at the end of September or beginning of October.

If you don't do this, there is a good chance that your heating will be off for three or even four months without anything moving.

One of the biggest causes of boiler problems and breakdowns is due to inactivity and you can easily prevent this by briefly switching on your heating once a month through the summer.


Why summer is the best time for central heating maintenance

How to find a decent plumber

The importance of annual heating system maintenance