Mira 88 shower (gravity feed) no cold water

[Puzzled2016]

Plumber came round to fix leak (not from shower head, but from central spindle) using the Mira 88 service pack (936.12). This fixed the leak, but the shower now behaves in a most curious fashion.

With the mixer knob in the COLD position hot water flows but at a low rate. Advancing the knob towards the hot position, the water flow completely stops, but before the halfway setting. Then further turning the mixer towards HOT, hot water flows (at about the rate experienced previously in the hot position).

Plumber says that problem is an air lock in cold water feed, but I think that doesn't explain current mixer action (ie no water flow at all in intermediate position), and I think he made a mistake in applying the service kit.

Who is likely to be right?

 

[jeff the gasman]

I can’t comment as my crystal ball is in the van!
Can’t really fit them incorrectly though. Didn’t he try to remove airlock?

 

[Deleted member 267285]

Check the cold water storage cistern 1st. Who is likely to be right - No idea.

 

[Puzzled2016]

OK, so sent email to [email protected]. Will see what they say. If they confirm that problem could have been caused by incorrect reassembly of mixer valve will post further.

 

[Hugh Jaleak]

Been a while since I had one apart, but from memory it was difficult to get them wrong during reassembly. Servicing was just a case of replacing the various O rings, lubricating the moving parts and reassembly. I have to wonder if some foreign matter has got in there during the operation and is now causing the described issues.

 

[jeff the gasman]

Been a while since I had one apart, but from memory it was difficult to get them wrong during reassembly. Servicing was just a case of replacing the various O rings, lubricating the moving parts and reassembly. I have to wonder if some foreign matter has got in there during the operation and is now causing the described issues.

Everything including the ring with the spur has to be properly in place before full assembly can take place.
Foolproof if you ask me and my first attempt was a challenge a long moon ago.

 

[HERTS P&D]

Your plumber feked it up.

Andy

 

[Puzzled2016]

Well, finally the shower is fixed. I've lost count of how many times the mixer unit was removed and re-installed but on at least 4 occasions once reinstalled there was no cold water flow. This happened even when I had a different plumber in to have a go.

But this last plumber did finally get it to work by removing a washer. This washer was 25 mm in diameter (external) and where in came from, whether it was wrongly included in the service kit or was left in when it should have been replaced, I do not know. I was too overjoyed at having the shower finally working to bother to ask the plumber about its origin.

Anyway the You Tube video on servicing the Mira 88 shower (which I had brought to the original plumbers attention) does at two points warn about leaving a washer in (see from 9 mins onwards) when servicing. Apparently an old washer can get stuck in place leading to the new washer being seated on top.

The correspondence with the manufacture, whilst supplying a very detailed PDF on installing the shower, did not otherwise produce any useful advice.

What should have been a fairly simple and inexpensive job turned into a nightmare of broken promises to attend, buying parts that I could have avoided buying, and several months of choosing between having a lukewarm shower or getting scalded as I juggled with duration of the boiler being on.

MY ADVICE if you do need have you Mira 88 shower serviced - insist on your plumber watching the You Tube video carefully, and check that the shower works before you pay him.

 

[Puzzled2016]

This is the You Tube link referred to above

and this is the link for the PDF guide

http://resources.kohler.com/plumbing/mira/pdf/p2741-11-mira-88-installation-and-user-guide.pdf

see pages 28 to 33

 

[jeff the gasman]

Oh yeah I remember that washer. It’s a friction washer, sits in the bottom of the valve body.