ChatterBank2 mins ago
Hot Water Flow In Kitchen Sink.
34 Answers
Has anyone any idea as to why the hot water tap in the kitchen is so pathetic? We did have a Homeserve plumber have a look at it and he said it was probably an air lock but didn't do anything about it. The rest of the taps in the house are fine and the cold water, from the same dual swan neck tap, comes out fine. When we switch from cold to hot, the pressure is minimal and it takes ages to fill a bowl with hot water in the kitchen sink.
Answers
If you have a hot tank Tills it is probably gravity fed( the weight of water in the tank determines the pressure) That being the case the pipe work could have a partial blockage reducing the flow, or as I have said the tap is itself goosed. Visual inspections from tank out to tap is the first step.
20:20 Tue 02nd Mar 2021
Can we ask Tills, is the hot tank upstairs or even in an attic or loft? If you live in a bungalow(I do) you do not have much of what is called a "head" of water. (no weight behind it) The bottom of the tank is therefor liable to be only about 4ft off the floor. The hot out pipe is going to be at the bottom(obvs). Your bath and bathroom basins are going to be fairly low but if you put a swan neck tap on a 930mm kitchen worktop sink then you have just halved the pressure if the swan neck tap is one of the Franke bigguns. ( the top of the swan neck will determine the height). It may even be above the tank outlet. That would reduce the hot pressure/flow without any other restrictions like the armoured connector link as well. You are basically trying to deliver hot water through a straw ... uphill.
The fact you do have a some flow, says you don't have an air lock.
In a gravity fed system you need to allow the water to flow a easily as possible.
The first thing I would do is have a look in the water tank.. In the past I have removed pigeons, mice and even a rat from loft tanks. Any of these would reduce the flow.
Failing that I would be looking under the sink. The flexible braided hose could partially collapse after some time. I always carried flexible pipes with a larger bore, increasing the pipe diameter by a couple of millimeters could increase the flow by thirty percent.
The other culprit that will reduce the flow is the service valve. Nearly all of them reduce the flow. In a gravity fed system I would only fit a 'full bore' valve.
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