Are you a homeowner keen on DIY and on keeping your new boiler in tip-top shape so it lasts as long as possible? Are you concerned that you shouldn’t be fiddling with your boiler as it’s a gas appliance? You’re absolutely right, yet it is still possible to do plenty of DIY around a boiler and loads of checks on it, without interfering with its proper operation.
Here’s a massive list of 20 checks, tests, inspections and even DIY jobs you can do to keep your boiler running smoothly. Most of these will be visual inspections, so very easy to carry out but also well-worth doing regularly. Most issues picked up from those inspections will probably need to be addressed by a gas engineer though.
The one job that everyone knows about. Get yourself a radiator key or spanner and start from the lowest rads. It’s best to do it with the heating off otherwise air could be introduced in the system on some configurations when the pump is running.
Perhaps the one check that most homeowners know and that even manufacturers encourage users to adjust on a boiler. The system pressure shows the water pressure in the boiler and radiators. It should be around 1 – 1.5 bars and if it drops too low, the boiler will cut out with an error code.
To top up the pressure, you’ll have to familiarise yourself with your boiler and any filling loop present as it’s slightly different for each make. Top it up with the boiler cold to avoid thermal shock to its innards.
If you want to get wet and dirty, this is the job for you. You’ll need to close the valves before and after the filter and drain the water. Then on some old models remove the magnet and rinse it. On newer models, remove the magnet from it’s dry pocket and flush the filter. There are many different brands of magnetic filters and their designs vary slightly. Be warned, on some plastic filters such as the Adey one, the cover will leak afterwards and the o-ring will need replacing. Perhaps it’s not worth the trouble!
Check that the flue terminal is not blocked. It’s very easy to do but also very important for the safe operation of the boiler. This is especially important if the boiler has stopped working and is showing a combustion error. It is all to easy to lean a ladder or a sheet of plywood or MDF against it and forget about it. Make sure the flue terminal is not obstructed by bushes and climbing plants.
One check that all gas engineers will do is to make sure that the flue is visible along all its length, except when it passes through a wall. So don’t build any enclosure to hide the flue unless there is a hatch door for easy access.
You can do a visual check along the flue yourself. Look for leaks below, signs of corrosion, sagging along its length or even joints coming apart. Any issue you find will need the immediate attention of a gas engineer as a defect on the flue in a property can release harmful gases and have serious consequences.
You may have heard this one from a government campaign a few winters back. This is one great way to reduce gas consumption – reduce the temperature at which you heat your radiators.
How to do it differs a lot from boiler to boiler. On some, like the Baxi boilers, the temperature dials are right there in your face while on others they’re hidden in a digital menu.
Just as you save money reducing the flow temperature, you’ll also save money if you reduce the hot water temperature at the taps, especially if you mix it with cold water to cool it down. The option on the boiler to do this will be near the flow temperature setting. Look out for DHW – direct hot water.
This only applies to combi boilers, not to systems using a hot water cylinder.
Keep an eye out for leaks, under the boiler and under radiators. This is especially important if you find yourself topping up the system pressure a little too regularly. Water may be escaping somewhere. The most dangerous leaks are the small ones that go unseen. They drip and rot and rust until the material gives way and it’s a catastrophic failure! So if your boiler is in the loft, do go up there from time to time and have a good rummage. Don’t wait until the ceiling falls on your head. That’s also why it’s not a good idea to fit a boiler in a loft.
And while you’re on the lookout for leaks, pay attention to any signs of corrosion. No leaks, no corrosion but if the leak is internal and small, the only sign may well be rust spreading. A little corrosion visible outside may well be extensive on the inside…
PRV stands for pressure relief valve and its job is to release water from the heating system if the water pressure exceeds 3 bars. So if you see it leaking, it is doing its job. Sometimes though, it leaks because it is defective. Both cases require attention from a gas engineer. If you’re topping up the system pressure, a leaking PRV could be the reason why.
Unfortunately on some boilers, the PRV is combined with the condensate pipe, so checking for a leaking PRV is not straightforward. Otherwise, look out for a small, 15mm copper pipe protruding slightly outside from the wall and often bent to direct water down and against the wall.
Another campaign run by the heating industry to raise awareness among homeowners, so hopefully that will have seen some success. The condensate pipe carries out the water that has condensed from the fumes – it is a condensing boiler after all. The pipe can often be identify by its white colour and plastic material. This water is slightly acidic and must be disposed of safely. In winter, the water in the pipe can freeze if it runs outside.
Look out for leaks from this pipe as the acidic water can eat through any copper pipes below in no time. If the pipe is outside and not insulated, consider insulating it. Why wait until the water has frozen inside and caused the boiler to malfunction?
There are numerous pipes below a boiler, most needs to be fully open or fully closed. In fact, the only ones that need to be fully closed are the valves at the filling loop. Everything else stay fully open. You should already be familiar with the filling loop in order to top up the system pressure, so if you see any other valves not quite fully opened, just make sure they in line with the pipe so they’re fully opened. If unsure and the boiler is working fine, leave it as it is.
Sometimes, a filling loop that’s not fully closed can cause mains water at pressure above 3 bar to enter the heating circuit and cause the pressure to exceed 3 bars and the PRV will kick in, causing it to let water flow out. So by making sure the you’ve properly closed the filling loop after use, you can stop that PRV from leaking. Or if you find it leaking, just make sure the filling loop is fully closed.
If you have one, don’t forget to test it from time to time. Similarly for fire alarms. These very easily go unseen and forgotten. And if you don’t have either, get both today. There’s no reason not to, they can save your life and property and their cost is negligible in comparison!
Check your radiator thermostatic valves to ensure they are on the right settings for you. Too hot and you’re just wasting heat. This is a check best done when checking for leaks.
If your room thermostat is wired, you can’t move it and hopefully it is correctly situated. If you have a portable one, ensure you’re leaving it in an appropriate location. This means a place where it won’t be reading an incorrect temperature. This could be near an open window or external door, in direct sunlight, next to a source of heat like a radiator, too high up near the ceiling or too low down near floor level. It’s recommended to be around 1.5m from the floor.
Yes, despite this long list of checks, you still need your boiler serviced. The checks listed here are important and helpful, but still external. There is more going on inside the boiler and more tests to be carried out. The checks are also pre-emptive, so keeping an eye out for leaks means you’re acting early if something minor happens, instead of waiting up to a year for your gas engineer to come and tell you that your boiler is so rusted that it is beyond economic repair.
If you’ve been convinced to get your boiler serviced, the next step is to ensure easy access to the boiler. Don’t build cupboards, shelves or compartments around the boiler that will restrict access or even make the boiler cover impossible to remove. Your engineer will charge you more for the extra time spent!
Do not box in the flue, unless it can be removed easily without any tool. In the loft, ensure the floor is boarded up. This should have been done at the time of installation. In fact, if you follow this guide and visit your loft occasionally to check the state of the boiler, then you will benefit the most from a boarded floor.
Most checks listed here are very simple to do, safe and yet so important. They can save you a lot of money and even your life. Most of them just require you to have a look around, as simple as that, from looking for leaks, corrosion, a sagging or blocked flue, to testing your CO and fire alarm.
The most involved work here, cleaning out the magnetic filter, is the least important and can be done by the gas engineer. Above all, don’t neglect to get your boiler serviced once a year.