Why do I not have hot water from my shower, but I do everywhere else?

[formulaquestion]

Mumsnetters you are my last hope... my shower won't get hot.. slightly warm yes but not hot enough to use.

We have hot water working properly from all other taps.

The shower unit is reasonably new and I also called the company because it's under warranty and they said it won't be that causing it.

Can anyone advise me? I have had 2 plumbers who both barely looked and said they don't know

how is the water pressure?
we had an issue with the shower when a new estate was added to the water network and our water pressure dropped considerably.

Water pressure is ok and hasn't changed since the hot water stopped

Water pressure is ok and hasn't changed since the hot water stopped

We had this. It was the filters in the thermostatic mixer that were gunged up with limescale. We took them out, dumped them in vinegar overnight, put them back in the next morning and hey presto, hot shower.

thanks for the pic.

You don't have a hot-water cylinder, do you?

There might be a small button on the mixer, near or behind the control knob. The button is to prevent the knob being turned fully high, as an anti-scald measure. See if it is operating correctly.

For some reason, bar showers are cheaper and not as good as round mixers. They are usually very easy to swap for new, though. The big nuts at the back (probably) screw onto an adaptor plate fixed to the wall, and a new one (probably) goes straight on. If you have the instructions you can try taking it apart in case the filters are clogged. There may also be limescale in the mechanism.

If you want a really good mixer, the round-knob Aqualisa is your best bet, though it probably costs five times as much as a bar mixer.

@PigletJohn thank you so much . Here I go with my screwdriver 🤣 wish me luck

Thanks everyone

@formulaquestion sounds like it!!

How did you get on Op?

@BenoneBeauty I didn't even attempt it after my DP said that i have to turn the water off at the mains. And that is in the street outside. No idea how to do it 😩

So sorry Op, what a nightmare for you!

There is usually a stop cock under the kitchen sink.

Literally going insane! I just want to wash my hair properly 😭

[quote formulaquestion]@BenoneBeauty I didn't even attempt it after my DP said that i have to turn the water off at the mains. And that is in the street outside. No idea how to do it 😩[/quote]
prise open the little hatch with the handle end of an old teaspoon.

If you have a water meter, there may be a blue T-handle

Or there may be an old brass tap at the bottom, under a layer of mud, rainwater and woodlice. Take a torch and a long ladle. you can wear gloves if you want.

It might be just inside where the front gate used to be, when the house was built, and it might have been hidden or buried by a previous occupant who wanted you to suffer when you get a burst. If you can't find yours, ask where neighbours, with similar houses, have it.

Once you have got access, there is a stopcock tool you can use to reach down to the "T," depending how far it is and what size.

Even if you have an indoor stopcock under the sink, you need to know where the outside one is, before the day you need it.

@PigletJohn thank you so much

I once had to dig out a stopcock in a muddy lane in the dark with rain lashing down and managed to dislodge a large chunk of granite hedge wall in the process.
Needless to say I wish I had followed piglet’s advice to identify stopcocks in a calm dry non emergency moment.