February 2015



A horrible noise can be heard around my home whenever the loft tank is refilling. The problem is particularly embarrassing whenever we have guests over. I have conducted some online research in an effort to find a solution, however nothing has proven fruitful. What would you recommend that I do?



I assume it is the sound of water filling into the tank that you hear as opposed to water hammer which can cause the pipes to clang and clatter. The noise is most likely due to a restricted water flow or a faulty ballcock valve. The valve may not be closing fully and shimmering on the water causing the noise. This is a common problem with a ballcock and is usually a relatively low-cost repair. You may need to replace the ballcock washers and/or check the ballcock release lever. If this doesn’t work, then replacing the ballcock assembly complete may need to be considered. The only difficulty usually with replacing a ballcock is the restricted access around a tank within the attic.

However, the following may also need to be considered:

Older metal tanks make most noise and may need to be replaced.

The tank must be on a proper support structure and not resting directly on the ceiling joists.

The tank must be insulated and fitted with a dust proof lid. Pipes must be supported and lagged.

There may be very good, and sometimes excessive, water pressure in the area resulting in more noise on filling. Reducing the flow into the house from the main stop cock outside might help. You can adjust the pressure with a pressure-reducing valve.

Other things to consider include a constantly flowing toilet cistern downstairs which would cause the water storage tank to constantly fill. Check and repair the toilet water closet ballcock as required.

Consider also the issue of water hammer which is the banging noises that sometimes come from plumbing pipework when a tap or valve is turned off and sets up a shock wave through the water which causes the pipes to vibrate and “shudder”.

Ensure the pipework is adequately secured, replace any defective float valves. Reducing the flow into the house from the main stop cock outside might help. You can adjust water pressure with a pressure reducing valve.

Sometimes, a simple bending of the float arm to reduce the filling of the tank might work. Works should be carried out by a plumbing professional.

Pat McGovern is a member of the Society of Chartered Surveyors Ireland (MediKids) Building Surveying Professional Group