Input water temperature for electric shower

[jouleflow]

I have a solar pv system that has an Iboost fitted to send excess generation to my hot water tank. Combined with my solid fuel back boilers we almost always have hot water.

I also have a cold mains fed 11kW shower - not a power shower. I would like to feed the shower with luke warm water via a preset mixing valve probably about 20 deg C. This will increase the input temperature of the input water & should allow me to use the lower setting on the shower unit. I'm told that this is feasable & I'm sure it has been done before. I can't find any info relating to a maxmum input temperature. The mains pressure works fine I want to use some of my free hot water. Any suggestions?

 

[Spoon]

Have you tried contacting the manufacturer and asking them?

 

[davesparks]

I would have a look at the specifications for your shower, it should hopefully tell you what is required of the incoming water supply.

 

[Gary K]

I would assume that the shower is designed to be fed with mains cold water. If you feed warm water through it, you will have to increase the volume of water going through the shower so that the output temperature of the water is as required. Most showers will cut off the power to the elements if the output temp is above a preset.
My 10.5 Kw shower is only used on low power through out the year- it just outputs less water at the required temperature during the colder months when the input temp is less.

 

[Charlie_]

Do you still have a boiler?

 

[jouleflow]

Do you still have a boiler?

Yes we have two log burners with back boilers that both feed the tank.

 

[jouleflow]

I would assume that the shower is designed to be fed with mains cold water. If you feed warm water through it, you will have to increase the volume of water going through the shower so that the output temperature of the water is as required. Most showers will cut off the power to the elements if the output temp is above a preset.
My 10.5 Kw shower is only used on low power through out the year- it just outputs less water at the required temperature during the colder months when the input temp is less.

Yes that is fine, what I believe could happen is that we will have a very fast flow on the lowest setting. Win Win.

 

[Charlie_]

Do you use your boiler as the primary heat source or just as back up for when the other 2 are not producing heat?

 

[Gary K]

Yes that is fine, what I believe could happen is that we will have a very fast flow on the lowest setting. Win Win.

If you could pre warm the water enough, you could turn the shower to cold and still have a warm shower.
Pressure would probably be an issue so you might need a pump.

 

[jouleflow]

Do you use your boiler as the primary heat source or just as back up for when the other 2 are not producing heat?

The log burners are our primary source of heat, they heat the water in the energy storage tank which in turn feeds the radiators & supplies mains fed hot water via a coil. This tank is always being topped up by the solar excess generation that feeds two immersion heaters. This gives us hot water throughout the year. I don't have any other boiler as I have no gas.

 

[jouleflow]

If you could pre warm the water enough, you could turn the shower to cold and still have a warm shower.
Pressure would probably be an issue so you might need a pump.

The shower is mains fed so we don't have a current pressure problem. If I fit a mixing valve to control the input temperature I think the pressure would remain the same.

 

[Charlie_]

Sorry I read that wrong, thought you said you did have a boiler..
Well that’s a good set up you have then..
Does it cope all year round with heating and hot water? How many in your house and what type of heating do you have?

 

[jouleflow]

Sorry I read that wrong, thought you said you did have a boiler..
Well that’s a good set up you have then..
Does it cope all year round with heating and hot water? How many in your house and what type of heating do you have?

We use the log burners to heat two rooms and 8 radiators. There are also 4 economy 7 radiators to take the chill off in the morning. These keep the house nice and warm all year. The solar iboost set up takes care of the hot water. This is for a house with 4 adults.

 

[telectrix]

be civilised and use the hot water for a bath. unlike a shower, it will not swamp your jack Daniels or extinguish your smoke. if you feel the urge to have a shower, go out in the rain.

 

[Wilko]

Hi - In theory, increasing the input water temp will mean the output water can be hotter for the same flow and power, or any combination of these depending on the heater controller’s capability. However, as has been said at some point it might just trigger the unit’s thermal protection and shut it down. If you can advise the make / model we might be able to be more specific.

This one lists max input water temp as 28C, for example.