Luke’s tip of the month – Simple heating system maintenance.
12 Jan 2015 Lisa Smith
Happy New Year to you all! This month Luke gives a few tips on keeping your heating system running smoothly….
With the weather turning colder, no one wants lukewarm radiators or even worse, a central heating system that isn’t working!
Sometimes there are simple explanations for why the heating system isn’t working, and can be fixed without having to call out a heating engineer. Usually, all problems lead to the same solution: air. Air in the system can be problematic and a general nuisance. It can cause vibrations in the pipework, radiators that aren’t functioning properly and eventually, on pressurised systems, a boiler that will refuse to work!
When tackling getting rid of air, make sure the system is off from the very start. If the system is on, it won’t give you a true reading of what pressure is actually in the system as the pipework will be expanding and contracting with the heat. If the circulating pump is running, you can also introduce air into the system, so make absolutely sure that everything is off.
There are two types of central heating systems: open vented and pressurised:
Open vented means that you will have a small header tank in the loft space with a vent pipe that loops over the top and points into the tank, taking up any expansion of the pipework and venting it into the tank. Typically this system will naturally vent the air out of the central heating but depending on how the system is configured, you can still get airlocks in the radiators or pipework.
A pressurised system, or sealed system, doesn’t have tanks and will rely on being filled manually with a filling loop device somewhere on the system (typically on the boiler). This is easily identified, as it will have a pressure gauge as shown in the picture!
When bleeding radiators, always start downstairs, as air will naturally travel up so it’s best to check that the downstairs ones haven’t got any air locks trapped in the pipework/radiator. Bleed it with a radiator key into some tissue or an old towel that you don’t mind getting dirty, as some systems will have black sludgy water (Powerflushing blog to come next month for more details on how to get rid of that!). Bleed the radiator until water runs for a few seconds without spluttering any air and tighten up the bleed nipple. Wipe off any excess as if you see water at a later date you might believe you have a leak!! Go round the whole downstairs circuit of radiators and then do the same with the upstairs radiators.
With a pressurized system you may have to top up the pressure on the boiler, always refer to the Boiler Manual on how to do it. Generally you’re looking for a pressure of 1.5 bar when the system is cold, Boiler Manufacturers may have a specific setting they prefer it on but this is the one I’ve always found most boilers run comfortably at.
The above are just a few tips to help you. As with most things though, you have to feel competent in carrying out these things yourself, otherwise you can get in a muddle and cause more issues! For advice on keeping your system performing at it’s maximum capacity, including servicing your boiler, Powerflushing your system, or even bleeding your radiators, contact us on 01473 353636. We are there to give you piece of mind this winter that you’ll be warm and stay warm through the coming months.