Kitchen hot tap fine/bathroom hot starts and then petersout

[CURIOSITY]

I have a closed CH system with hotwater cylinder upstairs about 5years old. The boiler is in kitchen. The cold feeder to the H/W cylinder has an extension with drain tap. The pressure reads normal at 1bar. Problem started 3 days ago. Please help with any solutions.Thanks.

 

[gas4you]

Faulty tap washer/ tap body?

 

[CURIOSITY]

Thanks Dave,
I will have a go at it and report back
Joe

 

[CURIOSITY]

Hi Dave,
Did remove tap, but no problem there. Even with the tap removed water flows for a few seconds and stops.
Also, if I allow the down stairs kitchen on, for a longer time the flow peters out there, as well.
When I bled the short spur drain- cock of the C/W inlet to the cylinder,situated towards the bottom end, the water is cold .
But the top end of cylinder is warm/hot.
After draining for a little while and when I open the H/W taps there is gurgling noise of the air with some water and then stops flowing altogether.
Could it be due to an air-pocket . If so how does one bleed it out ?
Any suggestions please?
THANKS AGAIN
Joe.

 

[JohnD]

Does the pressure gauge show a drop as soon as you turn tap on? It might be the supply to the cylinder that has the fault (I understand that it is one that runs at high pressure from the mains supply?).

If you have a pressure-reducing valve on the supply from the mains to the cylinder, it might have gone wrong (mine does, especially if not used for a while)

 

[gas4you]

JohnD, I am now assuming rightly or wrongly now that op has system boiler and standard vented cylinder

OP I sounds like a partial blockage in the cold feed to the hot water cylinder, so when the hot taps are off the pressure builds up for a few seconds hot water then runs out.

Go to hot water cold feed gate valve and turn off. Run all hot taps until nothing comes out. Undo nut on bottom of gate valve and seperate pipe. Put bucket under valve and open it. Does cold water gush out continuously? If so blockage will be after this point. If no water comes out you could check your cold storage tank outlet or connect hose to gate valve point and blast through with cold mains to see if it will clear.

Worst one I had was a dead mouse stuck in the cold fill pipe between tank and cylinder. Tank didn't have a lid on it!

The way it shot out with the mains pressure it could have been the first mouse in space

 

[kevplumb]

Go to hot water cold feed gate valve and turn off. Run all hot taps until nothing comes out. Undo nut on bottom of gate valve and seperate pipe. Put bucket under valve and open it.

only if the valve is ABOVE the cylinder

 

[gas4you]

I just assumed this in my own mind kev

By the way, I heard you first time

 

[kevplumb]

we do mate, the average novice at the game won't

 

[CURIOSITY]

Thanks every one for your help. This is how I ultimately got it working.
Took a long garden hose, fixed one end firmly with an adapter to the cold tap in the kitchen (meaning main pressure) held the other end with a noozle into the outlet of the feeder tank and blasted, keeping the H/W and C/W taps opened for about 1 or 2 mts.
It did not work the first time. Tried again for a further 2 or 3 mts, the H/W tap in the bath room began to splutter/spitting air and water With that the problem seemed resolved to this day after 4 days