Hot water problem

[niceguy]

Hi Everyone!

After fitting some new taps in the bathroom yesterday,
I find today that the shower is no longer working and
that the hot water only lasts for a few mins and then
there is no hot water coming out at all (its the same
in all the taps downstairs and up). The cold water
is fine and if I leave the hot water for a little while
then I will get a few mins of water until it dies down
again. Do you think shutting the valve off yesterday to
fix the taps has caused some kind of blockage? Is there
anything I can do to fix this? We have a back boiler
syetem.

Thanks for all your help in advance

[Phelps]

When you shut off some main valve, it is possible that the washer came off and is lodged in the seat area of the valve. The reason you get pressure initially is that in theory, you could have only one drip at a time supplying the water. But let it sit long enough and even those drips will build up to the established water pressure. So then when you turn on a faucet it will come out good and hard...at first. Then it will steadily peter out.

It is how slow the water runs at it's slowest point that indicates the kind of blockage you have. And yours sounds pretty blocked. And it is blocked at either in the cold water line before the water heater...yet beyond where any cold water branches off to some other faucet, spigot, laundry hookup or whatever... or at the hot water heater's cold water side shut off valve, or in the hot water line just after the water heater, but before it gets to the place in the line that splits to feed the different faucets.

You can test to see if it is before the water heater or at the water heater's shut off valve by hooking a garden hose to your water heaters drain fitting and then turning on the drain and see if you have actual pressure there, *that is sustained*. Leave all faucets off in the house when doing this test. Reason: A water heater will not even drain well if all the faucets are closed. Therefore, if you have sustained good pressure coming out of the water heater drain, then you will KNOW that there is no obstruction before the water heater, nor in the water heater's shut off valve.

But if the water heater drain valve DOES peter out, then you know it IS in the cold water line before the water heater...but also before any other branch off to some other cold water faucet.