Troubleshooting Heating & Plumbing 



Cold top section of radiator?

This would indicate that air has got into the system and has become trapped. The air will rise to the top of a radiator, create an air pocket and therefore prevent hot water from reaching it.

Turn the heating off, use a radiator key to slacken the bleed valve at the top of one end of the radiator – there will be a hissing noise as the air escapes and as soon as water appears close the valve. Check the pressure gauge on the boiler – refer to your user manual for guidance. The pressure should read 1 bar; switch the heating back on and check the radiator.

Cold bottom section of radiator?

This occurs as a result of rust or sludge building up in a radiator and sinking to the bottom preventing the circulation of hot water. This requires for the radiator to be removed and flushed out and we recommend that you call us.

Radiators upstairs cold?

This is unusual and indicates the feed / expansion cistern in the loft has run dry and that the ball valve is jammed or not working correctly. Check that there is water in the tank and that the ball valve is operating freely and try again – if not call us.

Radiators cold downstairs?

Will possibly be as a result of a faulty pump – you will need to call us to test the pump.

All radiators not very warm?

Again, this indicates that there may be a build of rust or sludge and the radiators will need ‘power flushing’.

Radiators cool in one area of the house?

This is as a result of the radiators not being balanced so the radiators nearest to the boiler are taking more than their share of hot water. You will need to call us to balance your heating system.

Radiators heat output fluctuates?

This is normal – radiators heat output will naturally fluctuate when they are fitted with TRV’s (Thermostatic Radiator Valve).

No heating or hot water

  • Check that a fuse has not blown and that there is power to the boiler.
  • Check that the gas supply hasn’t been accidentally switched off.
  • Check with neighbours to see if the gas supply to the area has failed.
  • Check that there hasn’t been a power cut resulting in the programmer losing timer settings.
  • Check that the programmer is on the ON position.
  • In the event of loss of heating check that the room thermostat is turned up high enough.
  • Check that the pilot light is lit on the boiler.
  • Check to see if your boiler has a customer operated reset button – these are usually found on the front of the boiler – refer to your user manual.
  • Try turning the electric supply to your boiler off then on again – it may reset the boiler settings.
  • Check to make sure that your condensate pipe hasn’t frozen. If so try to unfreeze by holding a hot water bottle or heat wrap around the pipe or pour hot water (NOT boiling) over the frozen end of the pipe.
  • Check that the ball valve float in the tank isn’t stuck. The tank will be in the loft and if there is little or no water in the tank the ball valve will be stuck. Gently try and release it without forcing it.
  • Check the pressure gauge on the boiler – again, refer to your user manual for guidance. The pressure should read 1 bar.


Water gurgling?

Air may have got into the system; try bleeding the radiators. Turn the heating off and using a radiator key release the bleed valve at the top of the radiator – there will be a hissing noise as the air escapes. As soon as water starts to come out tighten the valve.


The pump which circulates hot water may be set too high. Try turning it down to a lower setting – refer to your user manual for guidance.

Noisy boiler?

This could be caused by sludge and scale within the boiler which causes some areas to heat up more than others causing intermittent banging. We recommend you call us to investigate.


Why are my heating pipes noisy?
When the heating is turned on pipework and radiators expand. Where pipes cross joists or radiators are held captive upon their brackets you may hear a series of clicks and metallic pinging as the pipes move in very small but incremental steps. This noise is normal and will cease once the system has reached full working temperature.
If you are able to hear the water flowing through the pipes this is often a sign of air in the system that needs to be released or can be caused by “velocity noise”; water flowing through a restriction, most commonly a radiator valve.
Chattering noises are normally related to failing thermostatic radiator valves.
Loudly knocking or banging pipework is often heard when the heating pipework, or boiler heat exchanger is blocked and must be investigated quickly before damage occurs.

What is Water Hammer?

Water hammer is velocity noise caused by water flowing quickly through a restriction like a ball, or float operated valve. These valves are fitted to cold water storage, toilet and heating cisterns (tanks). The noise is caused as the ball-valve closes, any wave motion present in the tank will cause the float to bounce and the pipes to bang where the bounce is less pronounced the noise often manifests as a humming or whistling noise. The most effective cure is to renew the valve, although some success can be achieved by slowing the flow of water through the valve.
What does the small tank in my loft do?
The small tank in the loft is called the “feed and expansion cistern”(F&E) it is filled via a ball valve and keeps the heating system full of water, as water is heated it expands and the volume of water in the tank will increase. The water in this tank should be cold and clean. Hot water in this tank or orange/brown sludge are signs of a problem and if left unaddressed could result in costly repairs.

Short, fat, thin or long radiator?
Aesthetics, the height of window cills, room type, the length of available wall space and the quality of wall fixing all influence the design of the radiator we recommend. Radiators normally are available in three different designs made up of a combination of panels (the water carrying part of the radiator) and convector’s (the wavy steel backing behind the panel).

By adding a convector to a panel radiator the surface area and heat output are significantly increased, add another panel for even more, and so on. By adding panels and convector’s we can make the radiator smaller and still achieve the heat output the room needs, however, all these layers add depth so can cause the radiator to extend too far into the room or space.

What size radiators should I fit?
When sizing replacement or additional radiators a number of factors need to be considered. The number and construction of outside walls, the ceiling height, dimensions of the room, the area and type of glazing and whether or not there are heated rooms above or below. Armed with this information and some clever software we can calculate the amount of heat needed to keep the room warm. It is the amount of heat required that determines the size of the radiator.

My radiator worked last winter but doesn’t now?
Some older or budget thermostatic radiator valves are prone to seizing when left in the closed position for extended periods of time. As with all valves it is good to open and close them every few months this will ensure that when you next operate the valve that it will work and allow heated water to circulate through the radiator.

Thermostatic Radiator Valves, do I need them?
Thermostatic radiator valves (TRV’s) measure the air temperature in the room and close automatically when the desired temperature is reached, this stops water from passing through the radiator, the radiator cools, the room temperature falls and the valve re-opens.
TRV’s allow you to set different room temperatures in each room where they are fitted. You may wish bedrooms to be less warm than the living room. TRV’s save energy and as such are a requirement of the Building Regulations.
Do unvented cylinders need servicing?
Yes. Unvented cylinders are fitted with a series of safety devices and these need to be checked to ensure that they are working correctly, filters need to be cleaned, air gaps replenished, or expansion vessels recharged. There is no legal requirement to service these cylinders but it’s good practice to have them checked each year.


What is a Megaflo?
Megaflo is a trade name often applied as a generic term for “unvented hot water storage cylinder”. These cylinders allow hot water to be stored at mains pressure and provide hot water at very high flow rates. Typically cylinders of this type are constructed of stainless steel and benefit from a 25 year transferable guarantee, many are compatible with solar panel supplementary heating of hot water. Before commonly available, the only way to increase water pressure was to install pumps. Pumps are noisy in operation, can empty the contents of storage tanks very quickly and can be unreliable.
Cleaning stubborn lime-scale from pans.
Spirits of salt or hydrochloric acid is very effective and available from most good hardware stores. Flush the pan then use a rubber plunger to push all the water from the “U-bend” or use a sponge to bail the water into a bucket. Open windows, the acid gives off nasty fumes. Wear a pair of gloves and some eye protection then pour the spirits of salt over the surface of the scale. Leave the room now and wait 3 minutes, use a paint brush or similar to gently agitate the chemical, do not use metallic objects to scrape away scale this will mark the pan. Wait a further 3 minutes and flush. Hey presto! Nice bright, white pan. Never use spirits of salt on copper or chrome-plated fittings it will irreparably damage the finish.
Blocked pan, what can I do?
A rubber plunger is the best tool for this job. Lift and thrust the plunger through the water-line as deeply as possible, 5 or 6 times in quick succession. This will normally work. If you don’t have a plunger, try placing a mop in a plastic bag.
Water leak, what should I do?
Try to familiarise yourself with the plumbing in your own home. Know where your stopcocks and gate valves are. Once every six months give them a turn, when fully opened always turn the head back half a turn, this prevents valves from seizing.
In the event of an emergency turn the mains stopcock off (turn it fully clockwise) first, this valve will most likely be situated beneath the kitchen sink, in the basement or just inside the front door of the property, beneath the floor, this will stem the flow of drinking water and stop any tanks from filling. If you can’t find an internal stopcock, then it will be on the pavement outside the property.
Then go to the airing cupboard, any valves closed in here could save you from draining the large tank in the loft. Open the cold tap at the kitchen sink and the hot and cold taps to the bath to relieve pressure. You’ve done about as much as you can now, water may continue to flow but will stop eventually. It is now time to lay down some towels and call us. We’ll send a skilled engineer to make safe and carry out permanent repair.