mira 722 shower unable to change temprature setting?

the gear wheel/cog in question in plastic is part no 352.01 cost about £10 ,in brass the part no is 352.03 cost about £ 20 direct from mira

mike
August 2016

Hi Jim here , I've had the same problem a few years ago with this shower mixer . This is a very weak point with this unit , as the splines on this little fellow are very fine and also it's made of plastic ! You can buy this piece on its own and easily change it in a few minutes ! This piece is for rotating the heat controller coil with in the mixer . Also make sure to put plenty of Vaseline on the assembly of this unit when replacing it . Ps , these spares are quiet expensive , and they are of only plastic , can't understand why they didn't make them from brass ! ..then we wouldn't have this problem accuring ever so often .

Jim Conlon
September 2015

Michael, September 2009, did not need to replace the temp. reg assembly. It looks as if the teeth were stripped in the splined bush in the lever item. This can be opened (two screws) and old bush replaced.
The damage can occur due to spindle being too stiff to turn. This can be removed and lubricated with vaseline.

Ted O'Keeffe
May 2013

Martin - the temperature control assembly prises off gently by inserting a screwdriver blade and twisting it on opposite sides. Be careful because if you damage the assembly it can be £50+ to replace! You can find an exploded view of the whole thing within the Mira 722 service pack or online

Kevin (not) the plumber
March 2013

I have the same problem with my Mira 722. I'm trying to take the spindle out to replace the washers with my service pack but I cant get the flow knob off. I've taken off the screw with the plastic disc saying Mira 722 but it doesn't look like there's a screw inside that you can turn to take the knob off to gain acess to the temp control etc...

I'm I missing something and can anyone help?

Martin
March 2013

you do need to turn the water off when taking the cover off!!!! but a good strip down and make sure the barrel rotates and after 8 years of hot only we now have a mixer shower. Wife very happy, took all day though.

trevor Wilson
October 2010

I have had this problem, you might find that the gearing mechanism which operates the bi-metal spring tempreture controll has failed because sometimes the plastic teeth on the large controll ring gear get striped smooth by the lower geared smaller teeth on the end of the controll arm. Then WHEREVER you slide the controll arm it will have no efect. Dismanteling temp regulation assembly will reveal the worn area. Solution, replace temp regulation assembly.

MICHAEL
September 2009

had the same problem. There is a brass sleeve inside the assembly which fails to turn because of corrosion. You do not need to turn off the mains water to access it. using pliers, remove the centre screw in the middle of the knob and pull it off (you may need a 3 legged puller to do this if it has been on for some time). Put the temp control lever in its centre position, remove the 2 screws holding it on and pull this off also. If you have a chrome plate covering the entry point from the back of the assembly, this can be prised off by use of a screwdriver leaving a chrome back plate. Remove the screws holding this on and pull it off. There are 4 brass screws holding the temperature control assembly on and htese need to be removed. If they are corroded on, they must be drilled off and replaced with the correct metric equivalent. Pull the cover off (a small amount of water will escape). You will then see a sleeve which should be free to rotate a small amount but will be stiff. Pull it off and clean the back section where it presses against the back plate using fine steel wool. Re-assemble and it should work.

Gordon
November 2008