My shower only gets warm not hot

Chickabiddybex

I need some advice. I have a combi boiler and a mixer shower. Unfortunately my shower won't get hot, it only goes from cold to warm. It used to work fine. The taps still get hot.

My shower is like this: https://www.diy.com/departments/triton-benito-rear-fed-chrome-effect-thermostatic-bar-mixer-shower/1516886_BQ.prd

I think I need to take the shower to bits to see if there is something faulty in there, maybe a valve or something. But can anyone help me with what exactly I'll be looking for? What do valves look like? What part is the cartridge? Which part of the shower should I be looking in? And do I need to turn the water off at the mains first?

Browntoa

The cartridge is the tap part , there's a valve to regulate temperature.

Is the water pressure good ?

https://youtu.be/eo2d1Tfp018

Ebe_Scrooge

One thought occurs to me. If you've got a combi boiler, it's possible that it's just to do with the outside temperature. A combi boiler works by taking in a cold water feed and heating it up "on the fly". There is a maximum amount of heat it can give out. Let's say, using purely hypothetical figures, that it can raise the temperature of the water by 40 degrees at full flow. In summer, if the incoming water is already at 15 degrees then the water coming out will be at 55 degrees. In the current weather, if the incoming water is at 2 degrees then the output will be at 42 degrees.


Does the water get hotter if you reduce the flow rate ?

Chickabiddybex

I did think it could be that, so I've already tested it and no it doesn't heat up if I reduce the flow rate. It also still did it today even though the temperature has picked up considerably compared to a few days ago.

big_mortgage

What is the temperature of the water from the other hot taps? If they are also only warm, it might well be the thermostatic valve is leaking cold through and needs replacing

bris

The cartridge in the shower may be faulty. If the taps are getting hot then that's the most likely cause.

Will2208

In my job I regularly deal with problems with showers and usually a new thermostatic cartridge will resolve a water temperature problem. I would contact B & Q customer service and they should be able to source one for you.

Chickabiddybex

I tried to get into the bar to get at the cartridge but I was unable to - it doesn't look like it comes apart. Just gonna get a new one, it's been there since before I moved in so it's not too bad!

Rexxel

Hiya,

I recently had the same issue with our new shower.

https://www.victorianplumbing.co.uk/burlington-avon-thermostatic-two-outlet-exposed-shower-valve-rigid-riser-kit-with-fixed-head

We had to get a new boiler anyway and expected that to solve the issue as at first it went warm and cold throughout. The new boiler stopped the fluctuation but the shower still wasn't hot, just warm.

We had to unscrew the valve bit and change the max temperature. I think there's a certain temperature that the manufacturers have to advise as the safe max temp but it can be increased.

It might say something similar in your manual?

Chickabiddybex

I figured it out - turns out the shower was made by "Big Shaq".

Will definitely have to buy a new one!