Shower Water Too Hot - Saunier Duval

[spidermonkey]

I have just moved into a new house. I know very little about heating etc. The shower is just a hose from the bath taps. The water from this is scalding hot making it unusable. Running the cold water simultaneously does literally nothing. Running the cold water from the bath only is cold, but together with the hot tap its scalding. The only way I can cool it slightly is by running the hot tap in the bathroom sink at full power which slows the pressure and very slightly the temperature but this is far from ideal.

The strange thing is the hot water from the bathroom sink and kitchen sink is at a perfectly acceptable temperature. The boiler makes NO strange sounds whilst running the shower. As stated the boiler is a Saunier Duval.

Any ideas?

Many thanks in advance

 

[Beerlover]

In order to help further, what model of SD is the boiler, and do you still have a cold water tank in the loft?

 

[spidermonkey]

The water tank is on the upper half of the airing cupboard. This is going to sound stupid but i honestly cant see a serial or model number or anything in fact to identify the boiler i have just checked again now. I have checked top, sides and under. The bottom third of the boiler face where the controls are - Top left of this is the timer, underneath pressure gauge. Most right hand side is on and off knob, left of that is the knob for heating levels and switching to just hot water

 

[Beerlover]

Right then.

First problem is that your hot water is at mains pressure while the cold is from the tank. this will make the hot overpower the cold to the shower as you will have effectively no head of pressure at the shower head. This can be solved by ditching the tank and connecting the cold to the mains supply.

Next on the control panel you will see two holes at the top left and right. Using a flat head screwdriver turn them a quarte turn and the flap will drop down. You will see the model type there. Check the ntc (temperature sensor) on the copper pipe front left is securely clipped to the straight part of the pipe.

Post back when you have done the second one. the first will need a plumber unless you are confident at diy

 

[spidermonkey]

1 screw turning with no resistance other frigging screw is flaking and not turning, will need wd40 before i gnaw away too much. will write back then

 

[Beerlover]

the screws turn the opposite way to each other

 

[spidermonkey]

Can you tell im not exactly a diy man! Ok flap is open its a F23 E. I slid the sensor that grips the front left pipe up by 2 inches - making it almost in the middle of the straight bit of pipe. The water is still the same unfortunately, and that whole pipe obviously gets scalding as you would expect. There are plenty of knobs are levers to play with but i havent fiddled with anything.

Additionally this may or not help - I have noticed that the cold water pressure from bath taps is low, nowhere near as high as the hot. Is there anything else i could try?

 

[Agile]

As has been explained you seem to have a cold water supply at low pressure from a loft tank. Connect it to the mains supply.

That stupid boiler probably had no temperature control? Otherwise you would have turned it down?

 

[spidermonkey]

Yeah no temp controls sadly. Was hoping there would be a way of turning it down somewhat using the internal dials are levers. Guess not
What i dont understand is why the temperature is fine elsewhere?