DIY Doctor UK DIY Forums

Having fitted a new kitchen mixer tap a couple of days ago, using flexi hose connectors supplied with the tap, I have switched the hot and cold water back on at the valves fitted under the sink. The flow from the cold water is strong, but the hot water is ok but not great. The morning after, the overflow from the large tank in the loft began leaking and when I turned the hot water supply to the kitchen tap off, the leak from the overflow stopped. Since fitting the tap I did notice that there was a sound similar to flowing water coming from the tap. Can anybody suggest what the problem might be here.

The old tap was connected using copper pipes not flexi and the new flexi pipes are a smaller diameter than the old copper pipes, not sure if this is contributing to the problem.

Did you take care not to twist the flexible tap connector? There is a soft rubber tube inside the braided outer which can easily be twisted which causes it to collapse and restrict the flow of water.

Yes i do recall twisting the hot hose l will get a new hose and replace. Would this restriction be causing the overflow problem. Thank you for your reply.

I wonder if the new tap is a non approved type with the water mixing in the spout. Is there just one outlet, or concentric outlets for hot and cold.
You may well need a check valve on the hot supply to prevent the cold back feeding into the hot.

The overflow problem could be coincidental but you might have disturbed a foreign body during the work and it could be lodged in the ballcock valve. An simple check you can perform is to manually open the valve wide by pushing down on the float then release. This will frequently dislodge debris which is keeping the valve from closing fully.

I've seen this problem before when fitting a kitchen. In fact, I've seen it several times. The first time, it took me until nearly 8pm one day at a customer's house trying to figure out what was happening.

Esentially, you have a faulty tap. There is a fault in the casting that is allowing the water to travel from the cold side to the hot when the tap is switched off.

You will need to return it for replacement.

plumbbob wrote:I've seen this problem before when fitting a kitchen. In fact, I've seen it several times. The first time, it took me until nearly 8pm one day at a customer's house trying to figure out what was happening.

Esentially, you have a faulty tap. There is a fault in the casting that is allowing the water to travel from the cold side to the hot when the tap is switched off.

You will need to return it for replacement.

Every day is a school day eh! I never met that situation before, but I will remember that for again. Thanks plumbbob