Is this a dumb idea?

breaking_free

Here's my setup.

Incidentally the water from the kitchen sink feels much hotter so I'm wondering if this is actually a problem with the thermostatic valve on the shower rather than insufficient heat output from the boiler. This shower is also just over a year old (I bought a bungalow that had been entirely gutted and refurbished - new pipework, new electrics, new roof, etc). So everything is new.

Had a close eyeball of the shower and couldn't see any allen-key friendly points of adjustment.

breaking_free

Just did a wee test: turned the hot water tap on in the bathroom basin - fantastically hot. So the problem appears to be with the shower, not the boiler. Any suggestions on things to check/do?

hedgewitchery

Hiya, 

I've been posting recently on a similar topic:

https://forums.moneysavingexpert.com/discussion/6417513/mixer-shower-issue-how-to-isolate

In my case, based on advice from my shower manufacturer's website, I tried first removing the shower head and then the hose to check they weren't impeding the hot water somehow: the water was still lukewarm, so I knew it wasn't them. Doing a bit of reading online, it turned out that it was likely to be the "cartridge", which I'd never heard of before - I just thought mixer showers were like taps and didn't realise there was a balancing bit doing something complicated in there! A brief description of a cartridge is here:

https://support.showerspares.com/support/solutions/articles/77000484439-what-is-a-shower-cartridge-#:~:text=Thermostatic cartridge (temperature/mixer cartridges,maintain a selected blended temperature.

Don't know if this is your problem, but thought it might save you some time on troubleshooting if it is!

ThisIsWeird

breaking_free said:

Just did a wee test: turned the hot water tap on in the bathroom basin - fantastically hot. So the problem appears to be with the shower, not the boiler. Any suggestions on things to check/do?

Ah! So the issue is with the actual temp, and not the amount of flow? Cool - that's sortable.

We'd ideally need to know the make of the shower mixer, or at least some good close-up photos of the temp control.

First, have a good look at it - turn the temp down and up, and look at the whole of the handle/lever, all around it. Is there a button on it? Or on the mixer body right next to the rotating handle? Almost certainly there will be - and this is the 'stop' to prevent the temp from being turned up by what the manufacturers consider to be 'safe'. You should find that if you press that button, the temp control will not turn a wee bitty further towards 'hot'.

I'm assuming that the mixer is a 'thermostatic' type, and has one control for 'on/off flow', and one for 'temp'? If you look real close, can you see any temps etched on the body - 39o or summat like that?

Anyhoo, have a good look all around the temp knob, and look/feel for a 'button' to press.

Slinky

We had this problem with a new shower, mentioned it to the plumber and he came back and adjusted it. The hot flow needed to be adjusted.  Our other shower had one of the buttons TIW mentions where you can push it in and turn past the 'safe' level. The plumber said it's to stop children scalding themselves.

breaking_free

Images below. I have rotated the temp control only to take the picture: I normally push that button and rotate the temp control round as far as it will go. 

breaking_free

No idea what brand of shower this is as I bought the house with this already in it. Probably a Screwfix special!

grumbler

Do you realise that it's thermostatic and you can control the temperature with the right handle (and flow with the left one)? Make the flow low and if temperature control doesn't work, then, possibly there is a problem with the thermostatic valve. Give some time hot water to reach the shower from the boiler first.

Belenus

breaking_free said:

Thanks all.
It's a Worcester 32Cdi compact - apparently this is a 30 kWH boiler (and less than a year old).
I'm female and always turn the temp up on my bloke's leccy shower when I stay over (yes of course I turn it back down afterwards). I'm pretty sure women like a significantly higher temperature than most men.
The shower is hottish, but nothing like what I'm used to. Wish I could measure the actual output temp...

Not always.

In winter I have a very hot shower, set at about 3/4 of the way to hot, whereas my wife turns it down to about 1/2 way for her shower.

In the warmer weather I have a cooler shower and in very hot weather I have the shower set to fully cold whereas she stays nearer to half way all year.

breaking_free

grumbler said:

Do you realise that it's thermostatic and you can control the temperature with the right handle (and flow with the left one)? Make the flow low and if temperature control doesn't work, then, possibly there is a problem with the thermostatic valve. Give some time hot water to reach the shower from the boiler first.

Hi yes I do know this. The left side controller also determines if the waterfall showerhead or the hand-held showerhead operates (it's a dual headed shower as shown in the one of the original pics I posted). I can reduce the flow a little bit it makes no difference. I stay in the shower for 6 or more minutes which is plenty of time for the water to heat up. I'm leaning towards this being a problem with the thermostatic control.