Thermostatic shower

Hi everyone

I have recently had a new thermostatic mixer shower installed by my friendly local plumber. It is a Sfera drop plus

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However, the output is lukewarm at best and opening another tap in the house causes the shower temperature to plunge!!

I have had a new 30kw condensing boiler fitted and all other taps in the house are producing lots of hot water. Does anyone have any idea how I can improve this? Do I have a dodgy thermostatic cartridge?

Thanks in advance for your help

Reply to
Magpie
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Sounds like the water is the wrong way round. ie the hot is going in the cold and the cold is going in the hot.

Reply to
EricP

I will try switching the feeds to see if that helps. Thanks for the advice Eric.

Reply to
news.tiscali.co.uk

Surely if that was the case, turning the knob to cold would show if that was happening. Cartridges can be buggars but why not get the plumber back to do it properly. Must be under warranty

Reply to
Mal

Hi Mal

The plumber has tried switching the feeds but the shower just runs cold. Looks like I have got a dodgy shower... does anyone else have experience of this model (not one of the major brands, I know!!!).

Reply to
news.tiscali.co.uk

Is it fed from a tank or a combi boiler?

Mike

Reply to
Mike

It is fed from a condensing boiler which is brand new. There is loads of hot water to the adjacent bath. The hot feed pipe to the shower is hot to the touch.

Reply to
magpie

I'm no plumer and this is based on advice I received when I opted for a combi system ten years ago. As the shower is fed from the boiler it's relies on the amount of water the boiler can produce (measured in litres per min). Although this might behot and sufficient for filling a sink or bath it's prob not enough for a decent shower.

My combi boiler is 32kw and produces 13 odd litres per min, if I use the mixer head on the bath tap the effect is fine for rinsing my hair but would not make an impressive shower! Your 30kw boiler will prob put out a little less insufficient for a good shower IMO.

As it is fed from the boiler, any additional hot water demand will affect the amount of hot water supplied to your shower though I would have thought the thermostat would reduce the amount of cold water used to balance the drop in the hot water. There might be a small brief temp fluctuation but more noticable would be the reduction in water output from the shower.

It does say 'Ideal for use with a Combi Boiler' but probably one with a much higher flow rate. I had a look at the technical download not much help as it was in italian and looked like fitting instructions rather than specs.

The shower does look pretty though.

Mike

Mike

Reply to
Mike

Sorry I didn't get it for you. Reason I gave that answer was I put mine in 3 weeks ago and got exactly what you had for the reason I gave. Changing the feeds produced a superb shower. (Now overused by the whole household.)

Best of luck.

Reply to
EricP

Hi Mike

Since my first post I readjusted the spindle "set point" and the shower was more than hot enough with a really good flow rate. My plumber seems convinced that we have more than enough pressure to drive this shower.

The problem remains that the shower is not very controllable - and opening a tap elsewhere causes the shower temperature to drop drastically. I am thinking that this is a problem with the thermostatic cartridge. My plumber has returned today so I will see if he has any bright ideas otherwise I will try and get a new cartridge out of the manufacturers.

Thanks again for the advice everyone, your help is greatly appreciated. I will let you know how I get on...

Reply to
Magpie

This can happen if the valve does not contain a pressure balancing mechanism. Such a system is absolutely essential to a mains pressure shower, such as one fed from a combi. You can get external add on valves if your shower valve does not incorporate one.

Obiviously, your combi can only supply a certain amount of hot water, so if you turn on a hot tap elsewhere and use more than you can produce, it won't work. However, the pressure balancing valve will help in other circumstances, such as drawing a small amount of water elsewhere, or turning on a cold tap (or flushing a toilet).

Christian.

Reply to
Christian McArdle

Thanks for the info Christian

Right, this shower is driving me nuts now!! I have just tested the shower again and now it seems to have improved - not perfect but a definite improvement.

The shower is chucking out loads of hot water at a really good flow rate

- no complaints there. Yesterday, if a hot tap was turned on elsewhere, the shower would go really cold. Today, the temperature is (more or less) holding at a reduced flow rate. Yesterday, the temperature control had little effect - today, the temperature is much more controllable.

This is all very odd.... Could it be that the shower needed a bit of a "run-in" period??? Perhaps a bit of grit has been flushed out of the cartridge??? I really don't know what to make of all this - does anyone have an explanation.

Cheers aga>> The problem remains that the shower is not very controllable - and

Reply to
magpie

In message , magpie writes

There was a thread on Aqualisa showers recently. Different cartridges for each type of hot water supply. Yours may be the same but in Italian:-)

My shower cartridge (storage cistern type) only controls at a highish flow rate. If yours is similar you may exceed your hot water supply. I suppose you could try a shower head with smaller jets.

If the plumber chose the unit, knowing your boiler capacity, I think it is his problem.

regards

Reply to
Tim Lamb

Morning everyone

Well, I have just had my morning shower so I thought that I would report back!!! The shower performance seems to be pretty good now with the temperature remaining pretty stable even when a cold tap is opened. When a hot tap is opened the temp does drop (5 degrees or so) - presumably because the boiler output cannot match the demand.

Is this normal or would I get better thermostatic performance from a different model? This shower requires pressure of 2 bar to drive it - I have noticed that some showers can run off 0.3 bar.

Thanks once again for all the advice.

Reply to
magpie

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