Triton Ivory II water pressure low

[curpin]

Hi,
When the shower is ON, now, if I connect the shower head, the water starts coming out from the pressure release device (PRD), as if the shower head is blocking the water. The shower head is definitely fine.
When I take the shower head off and let the water flow, I am noticing that the water pressure is low, and also as if it is coming with pulses.

Some background before this has happened, the shower had been behaving inconsistently, sometimes hot and sometimes cold.
Now that we removed the shower head, the water is consistent, in terms of heat, but pressure is low.

Any help would be greatly appreciated.
I must mention it is a Triton Ivory 2 9.5kw.

 

[45yearsagasman]

Remove the hose from the shower end and try it. If it's ok then either clear the hose or fit a new one.

 

[curpin]

Thank you for the reply.
I have tried with and without the hose and filled a small tank to see the speed of water flow and they filled it both in almost the same time.
I conclude that the hose is not the culprit.

 

[seco services]

First did you fix the leaking prd ?

Water leaking from prd is showerhead/hose related problem.
Pulsating water flow can be stabiliser valve related fault.

You say your flow is low when you fill a bucket, At what number on the flow dial is it when you do the test ?

 

[curpin]

Hi, sorry if I was confusing.
The prd was not leaking, it was just kicking off as soon as I connect the shower head. I have my doubts that the shower head is blocked. I suspect the water flow is weak.
When I did my tests of the water flow, I used the cold water dial.

PS
some update, I bought a new hose and a new shower head. When I dial to the cold water, it looks fine, although the water flow is weak. When I dial the second hot dial, and then if I raise the shower up, the prd starts flushing out water at the same time as the shower head. If I leave the shower head downward (with the hose) then the prd stops flushing out water.
Any ideas?? thanks