I have a Mira 88 shower which draws hot water from the main hw tank.
It has worked satisfactorily for several years until this morning,
when the only way I could get hot water out of it was by removing the
shower head and lowering it, which is ok for washing my feet but no
good for anything else. Doing this I can get a good flow of hot water
but it stops as soon as I put the shower head back on its bracket. I
have checked the hose and the shower head and they seem to be ok.
It seems to me that there is a reduction in pressure on the hot water
but I can't work out why. Any ideas? (The hw tank is on the first
floor, the same as the shower, so the rise is just a few feet into the
roof space.)
TIA

"Peter Johnson" wrote in message
...
I have a Mira 88 shower which draws hot water from the main hw tank.
It has worked satisfactorily for several years until this morning,
when the only way I could get hot water out of it was by removing the
shower head and lowering it, which is ok for washing my feet but no
good for anything else. Doing this I can get a good flow of hot water
but it stops as soon as I put the shower head back on its bracket. I
have checked the hose and the shower head and they seem to be ok.
It seems to me that there is a reduction in pressure on the hot water
but I can't work out why. Any ideas? (The hw tank is on the first
floor, the same as the shower, so the rise is just a few feet into the
roof space.)
TIA

Is the cold water tank filling properly? Is there any foreign body in the
outlet in the bottom of the cold water (Header) tank?

"Peter Johnson" wrote in message
...
I have a Mira 88 shower which draws hot water from the main hw tank.
It has worked satisfactorily for several years until this morning,
when the only way I could get hot water out of it was by removing the
shower head and lowering it, which is ok for washing my feet but no
good for anything else. Doing this I can get a good flow of hot water
but it stops as soon as I put the shower head back on its bracket. I
have checked the hose and the shower head and they seem to be ok.
It seems to me that there is a reduction in pressure on the hot water
but I can't work out why. Any ideas? (The hw tank is on the first
floor, the same as the shower, so the rise is just a few feet into the
roof space.)
TIA


This system is cold water storage tank fed? The cold water tank is in the
loft? The hot water cylinder is one floor below the cold water tank? The
shower room is on the same floor as the hot water cylinder?

If the answers to these questions is yes, then make sure your cold water
tank is filling properly, because the actual pressure for this system is
coming from the highest point in the cold water storage tank.

If you answered no to any of the questions, then can you explain what is
different?

On Mon, 17 Nov 2008 16:43:25 GMT, "BigWallop"
wrote:


This system is cold water storage tank fed? The cold water tank is in the
loft? The hot water cylinder is one floor below the cold water tank? The
shower room is on the same floor as the hot water cylinder?

If the answers to these questions is yes, then make sure your cold water
tank is filling properly, because the actual pressure for this system is
coming from the highest point in the cold water storage tank.

If you answered no to any of the questions, then can you explain what is
different?

Your analysis is correct. I will investigate the tank in the loft
tomorrow. Thanks.

On 17 Nov, 19:59, Peter Johnson
wrote:
On Mon, 17 Nov 2008 16:43:25 GMT, "BigWallop"

wrote:
This system is cold water storage tank fed? *The cold water tank is in the
loft? *The hot water cylinder is one floor below the cold water tank? *The
shower room is on the same floor as the hot water cylinder?

If the answers to these questions is yes, then make sure your cold water
tank is filling properly, because the actual pressure for this system is
coming from the highest point in the cold water storage tank.

If you answered no to any of the questions, then can you explain what is
different?

Your analysis is correct. I will investigate the tank in the loft
tomorrow. Thanks.

I had to resolve a not dissimilar problem in my daughter's house some
years ago. I never did see what was causing a blockage in the cold
water feed to the hot tank, but I had to back flush the system with a
hose between the the mains tap and the hot tap, having drained down
the cold tank first. That didn't work initially but loosened up
whatever it was for the problem to disappear an hour after I'd given
up!!

The suggestion was that the blockage was caused by a slime film build
up.

Rob

My guess also! Has your cold tank a lid? Look inside before draining, it may
have accumulated gunge from years of dust in loft. One other thought---has
loft lagging or, on old lid fallen in ( made of Particle Board)? I've seen
both causes.
"John" wrote in message
...

"Peter Johnson" wrote in message
...
I have a Mira 88 shower which draws hot water from the main hw tank.
It has worked satisfactorily for several years until this morning,
when the only way I could get hot water out of it was by removing the
shower head and lowering it, which is ok for washing my feet but no
good for anything else. Doing this I can get a good flow of hot water
but it stops as soon as I put the shower head back on its bracket. I
have checked the hose and the shower head and they seem to be ok.
It seems to me that there is a reduction in pressure on the hot water
but I can't work out why. Any ideas? (The hw tank is on the first
floor, the same as the shower, so the rise is just a few feet into the
roof space.)
TIA

Is the cold water tank filling properly? Is there any foreign body in the
outlet in the bottom of the cold water (Header) tank?

On Mon, 17 Nov 2008 16:24:25 -0000, "John"
wrote:


Is the cold water tank filling properly? Is there any foreign body in the
outlet in the bottom of the cold water (Header) tank?


I've been in the loft and the tank was full, lid in place. I turned
the water off and drained the hw, all ok and nothing obviously
blocking the outlets. Tank refilled ok but no improvement in pressure.
It's now obvious, as well, that hw pressure is low at the taps but
obviously it's more noticeable when the shower doesn't work. I think
I'm at the limit of my capability now. I've got a plumber coming
tomorrow. Thanks to all for comments etc. I'll report back.

On Tue, 18 Nov 2008 15:54:07 +0000, Peter Johnson
wrote:

I'll report back.

Plumber arrived 10 minutes early, looked at the installation,
explained that he would try the tank blow-back method and asked me to
turn off the water preparatory to draining the header tank. Whilst I
was doing that he took the head off the shower, held the hose
downwards and turned the water on - result air lock blown out,
everything now ok. No charge for that so he's coming back to flush the
central heating, which I was recommended to do two years ago.