Dripping Mira 88 shower and stuck stop valve to water cyl

[John.Stitch]

The Mira 88 installed some 30 years ago is dripping hot water from the rose. Mira are pretty good with spares
So to take it apart I have to shut off the supply.
IE the cold inlet (no problem) and the cold supply to the hot water cylinder.

The AGA supplies hot water to the cylinder as well as the immersion heater (when turned on).

There are two (inlet) pipes on opposite sides at the bottom of the water cyl, one from the cold tank in the loft, this has a valve that I can turn 1/2 a turn but only after using a wrench to turn the black hand wheel. It is also starting to weep at the top or end of the valve that the wheel goes onto after my efforts.

The other pipe I assume is a feed from the AGA, I have found a valve for this.

It is a high scale area, Limestone so hard they stopped quarrying it 80 years ago.

So what's the plan Sam?

Do I continue trying to ease the valve?

 

[doitall]

Do not touch the AGA unless you want a big bang.

You need to isolate the cold feed to the cylinder, plus the tank cold to the valve, the best plan if the valve is stuck is to bung the storage tank, otherwise you stand a good chance of breaking the valve and not being able to turn it back on.

 

[seco services]

bung the tank in the loft, run the hot tap till it stops, then change the gate valve.

or isolate the ball valve in the loft, run tap till it emptys the tank, then change the gate valve.

 

[John.Stitch]

Thanks for your advice.

Had a closer look in the loft.
There are two tanks one is the overflow and the larger is the header.

The header is lined with scale, should this be cleared out, or will it come back anyway?

The valve feeding into the header drips a little, would a strip solve it or a replacement be better?

Would a bottle cork cut to shape do as a bung or is one to size from a plumber merchant better?

Not sure why I need to empty the hot water from the cyl via the tap.

 

[seco services]

Thanks for your advice.

Had a closer look in the loft.
There are two tanks one is the overflow and the larger is the header.

you mean f/e tank and cws.

The header is lined with scale, should this be cleared out, or will it come back anyway?

if you clean it out make sure you flush it all out or you'll be stripping the mira again.

The valve feeding into the header drips a little, would a strip solve it or a replacement be better?

cheap enough to buy a new one.

Would a bottle cork cut to shape do as a bung or is one to size from a plumber merchant better?

you can use a cork. just don't snap it in the pipe.

Not sure why I need to empty the hot water from the cyl via the tap.

cause the pipe from the tank to the cylinder is full of water.
open the tap and drain it off. or get wet.

 

[John.Stitch]

To resurrect this thread.
I removed some of the scale in the CWS and then left it for a week to allow the scale to settle.

Then I replaced the seals on the shower.

This week the shower started to drip again on connection point with the hose on the underside of the valve

Does this mean I have to replace the seals again because I did not remove all of the scale and flush it, or could it be something else? EG temperature effects? Can't see that myself though

 

[seco services]

you say its leaking where the hose screws to the shower mixer ?
replace the 1/2" rubber washer in the end of the hose.

 

[John.Stitch]

Sorry, I removed the hose and it leaks from the outlet threaded boss that connect to the hose at the bottom of the valve

 

[seco services]

did you replace that o ring when you fitted the seals ?
if i remember that o ring don't come in the service kit.

 

[John.Stitch]

No I did not, but it is irrelevant surely.

With the hose not attached to the valve there is a drip from the threaded boss on the underside of the valve to which the hose attaches.

Hope you understand what I mean.

 

[seco services]

i take it you mean when the showers not on ?

 

[John.Stitch]

That's right, it drips