What would cause the hot water pressure to decrease significantly from a faucet (say after 10 seconds)?

Question

This is happening in my tenant's unit kitchen sink.

Answer 1

I have the same problem periodically on a bathroom's hot water faucet (the only sink in the house that is not a modern washerless one).

The problem has always been that the washer deteriorates (from hot water and from faucet seat cutting into it). After it does it gets loose and tends to float off its location when the water is on and pop into the faucet's exit area. That clogs the flow with a slamming noise and no water comes out until the faucet is opened wider. The cure is always simple. Just replace the washer with a new one. It is a a fifteen minute job after you shut off the sink's wall valve.

In fact it started doing that again and the replacement is on my fix-it list for this weekend.

Answer 2

Replacing the washer might work but it sounds more like a volume problem. If your house is old, the lines may be undersized now. It sounds like your lines are filling up and holding a good pressure untill the valve is opened and the pressure is lost because there is simply not enough water there to be pushed. Look around the house at the heater and main supply line. If they are 1/2" they are definately too small. You may have restrictions in the lines or shut off valves, such as debris, corrosion, partially opened valves, etc, somewhere in the system causing the same problem. When the lines are not bieng used they fill up and are pressurized equal to your source. When a faucet/ valve is opened, the water after the restriction will rush out, but the water before the restriction will only push out as much as the restriction will allow the water to flow through.

Answer 3

change the faucet on the sink. especially if it's a single handle as these types have many washers inside and need to be replaced using a kit designed for it.

Answer 4

Check your pressure switch on your pump. Might have to be adjusted or it's faulty. You should have a gauge on your pump, turn your water on and when the pressure drops to 30 it should turn on and when it hits 50 psi it should turn off. If it drops below 30 psi use a screw driver and just tap it easy if it clicks on it's a faulty switch.

Answer 5

Maybe there is a broken pipe outside somewhere causing the decrease in pressure.

Answer 6

sediment [little piece's of stuff ] from an aging or old water heater may be traveling and gathering at a spot or spots in the popes just like a clog.

Answer 7

Sounds like a blockage...Call a plumber.

Answer 8

i think the hot water heaters pump is probably on its way out