Residents of several west Dublin towns claim their kettles and washing machines have been damaged since their water supply was changed last year.
The supply to north Clondalkin, Lucan and Palmerstown was changed by Irish Water from Ballymore Eustace to the Leixlip plant, which has a harder water supply.
While the water from the Leixlip plant is perfectly safe to drink, residents say the additional sediment in the water has caused damage to their electrical appliances.
Local Councillor Mark Ward has called on the water authority to install a filtration system at the Leixlip plant that would reduce the hardness of the supply.
He said: "Residents have contacted me about damage to electrical appliances such as kettles, washing machines etc.
"They have also reported a scum-like substance after they boil the water, dark colour, odd tastes and drinking water with grit and sediments.
"I have asked Irish Water to test a number of people's supply and they have assured me that the water is perfectly fine to drink.
"I have no reason to doubt that but it’s the quality of water that concerns me.
"You should be able to make a cup of tea without damaging your kettle or residue in your tea. It's as simple as that."
The Leixlip plant is due for a major upgrade next year. Councillor Ward has urged Irish Water to install a mechanical filtration system as part of this upgrade.
The Sinn Fein representative raised the issue at a recent area committee meeting of South Dublin County Council.
A spokeswoman for Irish Water said: "Both the Leixlip and Ballymore Eustace supply sources meet drinking water regulations but have different characteristics, with Leixlip water being classified as moderately hard compared to Ballymore Eustace.
"Hardness is a natural characteristic of much of Ireland's drinking water supply. Hard water contains high levels of natural minerals absorbed from rock and soil.
"Hard water is not harmful to your health, in fact, the higher mineral content of hard water (such as Calcium and Magnesium) may confer health benefits above that of soft water."
