Turn On Your Central Heating For The First Time

So it's that time of year again. The nights are drawing in and thoughts begin towards turning the heating on for the first time. Often the components that make up your heating system have been dormant for a few months and it helps to make some simple checks before you flip that switch. If you complete our quick checklist of tasks before you turn on your heating system this season you could avoid a costly problem or technical failure in the future.


The heating checklist we're about to describe can be split into two categories. Easy for the beginner and slightly more difficult and geared towards the skilled DIY'er. Before we continue watch the video below for a full description of how to get your heating system going for the first time. If that doesn't help then read on!

Learn more about plumbing with our Interactive House

Here's our checklist. Follow this to ensure you don't have any problems when turning on your heating for the first time:


  1. Bleed all your radiators. Use a radiator bleed key or a screwdriver (if possible) to bleed any air that might be present in the system. Remember to have a towel to catch any water that may come out and that both radiator valves are open. If you have a pressurised system you may need to top up the pressure in the boiler. If you don't have any air in the heating system then that's great. If there is you might want to call your local plumber and ask them to add some inhibitor to your heating system.

  2. Check the TRV (thermostatic radiator valve) is functioning correctly. If a TRV has spent a whole summer closed, it might be stuck closed and the radiator might not get hot. Make sure it can work properly. Do this by removing the TRV head from the valve body. Underneath you will see a small pin. Use a set of grips or pliers to wiggle the pin up and down to ensure it can open and close properly. If you want use a spray lubricant to loosen any stiff TRV's up. Do this to every radiator in the house.

  3. Balance the system. Close every lockshield on everyradiator in the house and then open a quarter to half a turn. This will ensure every radiator gets an adequate flow throughout the heating system.

  4. Make sure your room thermostat is working. If you have a mechanical room thermostat, you should be able to hear it click open and closed. For the newer types, you won't be able to perform this check. 

    That's the end of the beginner stage - the next is more advanced!

  5. Make sure the central heating pump has water inside and can move freely. Most pumps have a brass nut on the end. Remove this and bleed any air out of the pump. You can usually see the end of the pump shaft here also. Generally they have a small slot in the end, so you can pop your screwdriver inside and twist the shaft, making sure the pump is free and not at risk of seizing and failure.

  6. Check that any 2-port or 3-port valves can open and close freely. These valves control where the heat in your heating system is diverted to and if the fail it can mean a costly call out. Most have a lever arm on the end of the valve head which you can manually move open and closed. Most models have a detachable head also, meaning you can actually grip the valve spindle to make sure it's free. Doing this prevents the valve head to sieze and fail.

Now you should be able to turn your thermostat up. Turn the power on to the heating system and get all your radiators nice and warm.


Related Articles

Interactive House - Central Heating Controls (2-port & 3-port valves)

Interactive House - Central Heating Pump

Interactive House - Gas Boiler

Interactive House - Oil Boiler

Interactive House - Power Flushing

Interactive House - Radiators

Interactive House - Thermostatic Radiator Valves

Heating Systems Information Hub