Open vented systems for problems relating to sealed systems, seek the services of a professional heating engineer bleeding a radiator Cold top section of radiator This is usually a sign that air possesses into the system somewhere and has become trapped. Air during a radiator will rise to the highest forming a pocket stopping the recent water from going to that part. This can be released but remember to show the heating off first. Now, armed with a rag beneath, use a radiator key to slacken the air bleed valve which is at one end towards the highest of the radiator. There will be a hissing sound as the air comes out. As soon as water begins to flow, close the vent again and wipe off any water. Take care to not get scalded – the water could also be hot. The heating can then be switched back on.
Some systems have an automatic air release valve fitted.
This usually features a small red top which should be slacked to enable the air to flee. Radiators should not need frequent ‘bleeding’. If they do, air is getting into and this could be sorted out by knowledgeable heating installer Cold bottom section of radiator This is a symbol of rust and sludge build up which is sitting within the bottom of the radiator. Following the guides on removing and refitting a radiator, take the radiator outside and fail through with a hosepipe. If you’ve got the radiator standing on end, you ought to be ready to flush out most of the sludge. Remember to hold the radiator the wrong way up so you do not get sludge dripping on to your carpet. With an open vent system, you’ll also think about using a proprietary heating plant sludge remover. This will mean adding it to the feed and expansion tank and, a couple of days later, emptying and refilling the system. Follow the manufacturer’s instructions. Upstairs radiators cold This is most frequently a sign that the feed and expansion cistern within the loft has dry out. This should not happen and indicates another problem which must be sorted. It’s probable that the valve isn’t operating correctly. It may have jammed or be obstructed. Clear any obstruction or replace worn parts. Remember when refilling and adjusting the valve that there must be enough room for the water to expand when the system heats up. Therefore, when the system is cold, there should be only enough water to form the ball to float and cut the water coming in. Downstairs radiators cold This is a sign that the pump has packed up. Has it tested and, if necessary, replaced? All radiators cold or not very warm This again is a sign of the build from rust and sludge. See ‘Cold bottom section’ above. Radiators cooler in one area of the house This tells you that the radiators aren’t properly balanced. The nearest radiators to the boiler are taking quite their share of the recent water from the system. See page on balancing the system. Warm radiators upstairs when the heating is off, and predicament is on If this happens, it’s probably because the check valve on a gravity fed system has failed. In a gravity fed system, the recent water cylinder is heated by water from the boiler which flows thanks to the gravity and not a pump.
To prevent the water also heating the radiators when the heating is off, a check valve is fitted.
If this has failed, the radiators upstairs will begin to receive several the warmth. The valve will be got to get replaced by a heating engineer. No heating or hot water Make sure that the facility supply is on which a fuse hasn’t blown. Remember, if a fuse has blown, you ought to always rectify the cause first. As always, take care with any electrical inspection or work. See electrics safety.
Check that the gas or oil supply has not been turned off inadvertently.
In the case of oil, make sure you really have some oil within the tank by reading the gauge. Check that the programmer is within the on position which the thermostats are turned up high enough. Check that the pump is running. If not, get a heating engineer in to research. Check that the pilot light is lit. If it is not, follow the small print for relighting within the boiler manual. If none of those solve the matter, it’s time to call during a heating engineer. Feed and expansion tank overflowing If the valve isn’t isolation the water system properly, the cistern will still fill, and water will begin from the overflow pipe.
The usual cause is either a poorly adjusted valve or a worn washer.
These can both be remedied during a similar fashion to the valve of the cold-water tank.
Open vented systems
For problems relating to sealed systems, seek the services of a professional heating engineer
Several various things may cause noise problems with a heating plant.
This is a sign that air has got into the system. This can be released by bleeding air from the radiators but remember to turn the heating off first. Now, armed with a rag beneath, use a radiator key to slacken the air bleed valve which is sited at one end towards the top of the radiator. There will be a hissing sound as the air comes out. As soon as water begins to flow, close the valve again and wipe away any water. Take care to not get scalded – the water could also be hot. The heating can then be switched back on.
Some systems have an automatic air release valve fitted. This usually features a small red top which should be slacked to enable the air to flee.
Radiators should not need frequent ‘bleeding’. If they do, air is getting into and this could be sorted out by knowledgeable heating installer.
The pump which sends the water around the system may be set too fast. In this case, try turning it down to a lower setting. Pumps can also cause this noise in the pipework through vibration of the pipes. This can be eliminated by mounting the pump on special brackets which absorb the vibration rather than transferring it to the pipes. Finally, the matter can arise where undersized pipes are installed. Check this out with a heating engineer.
Knocks and creaking
Everywhere that pipes pass through other materials like floor joists or walls, there is a possibility that they will rub when they expand or contract unless enough space has been left. If you can identify where the noise comes from, investigate the pipework in the area to see where it is rubbing. Rubbing against floor joists where the notch out is too narrow to allow a little movement, is a common cause. This can easily be widened by cutting an extra slither away from one side with a saw and chiselling away the waste. Take care not to damage the pipe and do not deepen the notch as this weakens the joist. You can also pack a bit of fibre glass insulation around them to cushion the rubbing. This packing can also help where pipes come up through floorboards.
Sometimes pipes running beneath the floorboards have not been supported properly. If you find pipework which has a lot of free movement – for example where they run parallel to the joists – they will need to be secured. Fit a small batten, screwed between the joists, and use pipe clips to retain the pipes.
This may be caused by sludge and scale inside the boiler which results in some areas heating up more than others. The result’s usually intermittent banging caused by pockets of steam. The same sludge builds up can also restrict the flow of water which will result in noisiness. Air in the boiler may also cause noises. With any of these, it is recommended that you seek the services of a professional heating engineer.
There may be a lack of water. Check the feed and expansion tank. If it is not topping up when the ball valve is opened, there may be a frozen pipe, air lock, or the mains water may have been switched off.
Edinburgh Central Heating Services offer free estimates and range of skills. A 24-hour emergency plumbing service is also offered. For more information visit www.edinburghcentralheatingservice.com or telephone 0131 5102418