Mixer shower not very hot

Jeepers_Creepers

Don't forget to have your yet-to-be-convinced wife recording this on camera.

Just in case she's right...

Jeepers_Creepers

Silly Qs - what type of property is it - house, bungie, flat? What is on the other side of that wall - a cupboard? What about above the bathroom - a loft space?

Just in case it is possible to trace the supply pipes and find isolating valves.

ck7ah

Jeepers_Creepers said:

Silly Qs - what type of property is it - house, bungie, flat? What is on the other side of that wall - a cupboard? What about above the bathroom - a loft space?

Just in case it is possible to trace the supply pipes and find isolating valves.

It's a semi detached house. Behind the wall is the outside wall, it's an extension that was built by the previous owner. Above is a flat roof. The room next door is the utility room where the boiler is.

Jeepers_Creepers

No sign of the supply pipes to the shower, then?

ck7ah

Jeepers_Creepers said:

No sign of the supply pipes to the shower, then?

Nope, absolutely nothing. 

Jeepers_Creepers

Your call what to do, then. I think there's a good chance that you can undo the thermo cartridge without having to shut off the H&C first - ie by simply leaving the 'flow' control on the shower 'off', but I cannot guarantee that.

In any case, it's best having the supplies fully turned off just in case something goes wrong during the job...

What I would do is turn off the boiler and mains water. Make sure the immersion heater (if fitted) is offski too). Check that the cold taps have stopped running. Now shut off the red lever valve at the top of the cylinder (see pic). That is the hot water draw-off. (The blue-arrowed lever is - I think - the cold feed to the cylinder, which should be entering the cylinder near its bottom, but I don't know for sure, so leave that one).

Check - once you've turned the top valve - that the hot from your taps have stopped. Turn on your shower - now't should come out.

Prise off the end cap, reveal screwhead - remove screw. Pull the handle off.

Look at a pic of a typical thermo valve:

It has a large nut just before the valve disappears into the shower body - that's where you put your spanner.

Ok, these can be tight to start with, and you will be placing a fair amount of torque on the whole shower mixer. Two things to do; one is to support the shower body with your other hand as much as possible. The other is to slip the spanner on from below so the spanner handle it pointing downwards. That means you need to push it in towards the shower wall to make the valve turn, yes? I think this'll make it easier to control the force you are applying to it, whilst still pulling upwards on the valve body to counter this, but you try and see what's best for you.

Once it's out, take photos and measurements and use that to source a replacement. Give the old cartridge O-ring and thread a smear of silicone grease (every home should have a tube of this...) and replace, doing it up firmly but not tightly.

If you want, you can try turning on the hot and cold levers and see if water comes out with the flow valve still shut - if no water comes out, then you know you can swap that cartridge without having to turn off the H&C&boiler again.

ck7ah

Good news - wife called a handyman (an ex-plumber) as she didnt want me to touch it.  Luckily the issue was that the thermostatic value needed adjusting, so thats been done now and the water is hot again.  Apparently this happens after so many years on these showers.
Charged me £20 so didnt complain.

Jeepers_Creepers

Cool - to call out a pro was a pro move, done in a very pro way.

Happy New Hot Shower.