How to Maintain and Improve Heating Systems
It is most likely that there is no other system in your house with more working parts than your central heating system, and there are several things that can go wrong with the system. We are going to take a look at what can go wrong and how to prevent or remedy such problems.
Condensate pipe freezing
If the air temperature outside is below freezing it is possible for the discharge pipe from the boiler to become frozen. Moisture from the boilers flue is collected inside and discharge through the condensate pipe. If your boiler is registering a fault and the codes indicate that a frozen pipe could be one of the problems then the first thing to do is to try and restart the boiler. If it fails to restart you may hear a gurgling sound coming from the boiler. Either way, you should check the condensate pipe, this is the plastic pipe which is coloured black, grey or white, and if this pipe is not insulated it is possible that the pipe could be frozen and will need to be thawed.
You may wish to contact your installer or service provider if you have a service contract, as they will offer additional plumbing and heating advice. Otherwise you could attempt to unfreeze the pipe yourself. You will need to exercise extreme caution at all times while carrying out the work and you should only attempt the task if the pipe is at ground level and is easily accessible. One way to unfreeze the pipe is to wrap a hot water bottle around the condensate pipe, or you could use a hair dryer to thaw the pipe. Once you are satisfied that the pipe is no longer frozen you can attempt to reset the boiler. A permanent solution to prevent the pipe from freezing is to wrap insulation around the pipe where it is exposed to the outside air or in a cold environment, such as a loft. It is important to make sure that the condensate pipe has a minimum fall of 3 degrees, which works out to around 1cm every 21cm. If a frozen pipe is a regular occurrence it may be worth thinking about increasing the diameter of the pipe to 32mm where the pipe is fitted externally as most systems will have a 21mm overflow pipe.
Thermostatic radiator valves
Any new heating system that is installed would automatically be fitted with TRV’s, but it is possible to upgrade the old valves on your radiators. There are a couple of things that you would need to check first. If your system is several years old it may have imperial pipe sizes, in which case you would need to make sure that compatible fittings are still available. You also need to look at whether your system has a two pipe layout. This will mean that the radiators have an inlet and outlet connected to separate flow and return pipes. It is important leave at least one radiator with a manual valve, and that will need to be left open permanently to allow water to pump freely through the system.
The next thing to do is to check whether your valves are mounted horizontally or vertically and buy the corresponding TRV’s. Modern TRV’s have some interesting features, such as ceramic discs which are less likely to be affected by hard water. It is also possible to get TRV’s that have a frost setting, which can be handy when you are away from home and temperatures plummet. And some new valves have a remote sensor which can be positioned away from the radiator, giving a more accurate estimate of the room temperature.
Once you have checked out what you require you will need to drain part or all of the central heating system. If you unsure how to do this then consult your manufacturer or supplier for the right plumbing and heating advice. The system will need to be turned off before you begin, and once the system is drained you can then begin to replace the valves. There will be two nuts that need to be undone; one to the radiator tail pipe and the other that connects the valve to the radiator. Unscrew the head and tail from the new valve and wrap the thread of the tail piece with PTFE tape. This is a white tape available from all good DIY stores that ensures a watertight seal. First connect the valve tail piece to the water inlet pipe and tighten. Then re-connect the valve to the tail pipe. You will need to remove the white cap protecting the valve and replace with the valve head containing the sensor. When it all looks good and you are satisfied there are no leaks you can recheck and tighten the nuts. Once you have refilled the system you will need to bleed the radiators of the air that replaced the water you drained off, making sure at this point that all of the TRV’s are open to allow hot water into the radiators. You will find a small nipple at the top of the radiator that is designed to do this, but great care must be taken not to loosen the nipple too far so that it comes out; half a turn is usually enough to allow the air to escape. The radiators will have to be bled several times before all of the air is gone at which point you can adjust the thermostatic valves to the desired temperature for that room.
System power flush
The first questions to ask are, what is a power flush, and secondly, how do you know if you need one? Quite simply, a power flush works by attaching a power flushing pump to the circulatory system and then chemicals are passed through to dislodge any rust or sludge. Once this has been done, clean water is forced through the system to push any contaminants out completely. At the end of the flushing process, the system contains only fresh water, and inhibitors are added to this to prevent the build up of rust and sludge in the future.
Most people rely on a plumber or the heating contractor maintaining their system to tell them what is needed to maintain their heating. The downside to this can be companies recommending that you have unnecessary work done to drum up work. So it makes sense to arrange for at least three plumbers to check your heating system to see if they all have the same opinion. Should your heating system need a power flush, it is again worth getting several quotes before you proceed.
It is possible to carry out a power flush yourself as well as adding the inhibitors, and we shall be writing about this in a future article.
There are, of course, things that you can do in the attempt to prevent or limit potential problems with your heating system. Besides adding an inhibitor, you can also add a magnet filter to your system. They are simple to install and require very little servicing, but more importantly, they can save you a large amount of cash. They work by preventing a build-up of iron-oxide and non-magnetic deposits in the system, which can result in a loss of efficiency and fuel wastage.
The central heating system in your home is one of the most important and expensive investments you will make. So it is worth spending some time thinking about how best to protect and maintain it. In the age of the internet, plumbing and heating advice is never too far away.