mixer shower not working

We recently redid our bathroom ourselves. A family member did most of the heavy work including plumbing. Everything works except the new mixer shower. It's just a normal shower with hot and cold tap going into it. We put a new mixer valve on it and a new shower head/pole etc.

The hot water pipe going into the mixer is piping hot but only warm is coming out.

When in the shower you can adjust the heat upwards and it goes hot for about 2 secods and then settles down to a warmish temp. You keep doing this until the dial doesn't turn any more. It just keeps settling at a warm temp.

Any tips on if we could have done something wrong?

I trust the person who did the work as he has replumbed an entire house before including showers with no issues. We have either done something silly wrong or else there is something about the shower I bought that is wrong.

I think it is a Gainsborough that was bought in B&Q for about 250ish. The other taps and fitting I have bought from B&Q all work OK.

It was this one: [broken link removed]

installed with the circular face plate

Hi PGD1

If there is hot water going to shower unit I would suspect that there is a problem with the thermostatic control on shower. You should be able to get a service call free of charge as long as it is not installation related.

We can't see what we did wrong with the installation. It's not like there are many moving parts. I hope I can find the receipt and documentation.....

OK I lost the instructions but B&Q opened another pack and gave them to me. Very kind.

Now I can see I have a "Gainsborough GS500 Thermostatic Shower Mixer"

Q1) I thought I had a "mixer" not a "thermostatic mixer". Does this mean it is tyring to automatically set the temp in some way?... i.e. a maximum and a set level??? I can see no buttons or levers for this

Notes in the instructions:

- This mixer is suitable for any water heating system.... Great!

- This mixer is suitable for high and low pressure systems... Great!

- Q2) Hot Water Supply Recommended 60-65C.... We always can have scalding water from taps so I don't think there is a problem there

- Q3) A 10C difference must be maintained between the system hot water temp and the mixers maximum hot water temp..... WHAT MAXIMUM HOT WATER TEMP?????? Is there support to be a setting???? I do not understand this.

- Q4) Hot and Cold water pressures supplying this mixer must be balanced and from a common source.... I do not know if mine are balanced. I have cold coming from the water tank and hot coming from the immersion.



Any help greatly appreciated!

Q1 : the knob on the right is the temperture control
the knob on left is flow control

When the temperture is set, if there is a loss of pressure, temperture will remain at set level.


Q4: you will have equal pressure as cylinder is also feed from storage tank in attic as the cold

there is a problem with the thermostatic control. it can probably be bought seperately. Check out the parts listing in manual.

thanks,

i've been doing a bit more internet searching and it seems that there should be a setting inside for the max temp and also perhaps a cartridge and some filters that may have become clogged. It's brand new so I don't know.....

Yeah, some thermostatic showers need to be calibrated, (parts lined up right with handle) although I didn't think that was one of them. If so, there should be instructions in book.

the way it seems to be working is that no matter what I set the temp to, it resets itself to "warm". Even if i could reset the "warm" to "warmer" I would be happy enough.

Eventually you get to the max setting and can't adjust it anymore but if you turn it all the way back down again you can start all over again.... but it's only ever warm, not hot.

Anyway I shall experiment a bit more.

A question.... are all mixers thermostatic can you get a simpler one? Is it just that the thermostatic will adjust automatically if the tap is turned on?
I would be happy with a simpler one if it's solves the problem.

thermostatics protect people from getting scolded. think children etc.

You can just get a mixer. you control temp by mixing water. higher risk of scolding.

If shower is piped right hot direct into cylinder and does not share a line with anything else, and cold direct to tank with no tee's off it.This means that if there is water demand elsewhere in home they will not be drawing from shower supply hence effecting your supply and pressure. EG someone turns on a cold tap and person in shower gets scolded, or a shot of cold water when hot tap is on.

If they are direct lines to there respective water sources then a mixer would be safe to use.

Does the shower start with cold ??
Can you turn the control to go from getting cold water to getting as you put it warm water ??
If yes then the thermo control setting needs to be adjusted. as above mentioned

It should be in the booklet about setting the temperature. it can be tricky as it usually involves lining up the spindle that the control fits onto. have a thermometer at hand

i think it starts from cold....

There is NOTHING in the manual re adjusting/setting anything. I will give it another try I guess.

I still don't get the thermostatic option unless there is a MAX setting somewhere..... I can't see any max setting unless it's related to the spindle.....