Why doesn't hot water last long for showers?

[laujen]

Ive noticed with my power shower that if I have the setting on halfway around 4/5 the water doesn't seem to be as hot as it used to. Also there a four of us wanting to use the shower one after the other in the morning and after Ihave spent 5 mins in there and then my wife probably 5-10 mins when my daughter gets in she says the water is getting cold. Currently I have the HW setting to 24 hrs and also the immersion is plugged in as well as that seemed to provide a quicker back up when the water ran out.

Can anyone advise why the water doesn't seem to last long (and we only have it on half flow) and why it doesn't seem to be so hot?

I thought about replacing with electric shower but i guess that would mean a lot of rewiring work?

Thanks

 

[Agile]

To make it last longer you will need to reduce the flow rate. Measure it and tell us. Litres per minute!

Therer may be issues with the cylinder but you have not given us any details of that. Or the cylinder size.

For four short showers you need a 210 li cylinder!

Tony

 

[laujen]

Thanks Tony. We have always had the flow rate on half way and never used to have a problem so not sure why now? When you say the cylinder you mean the immersion heater tank? Does it make any difference having both the immersion on and the HW from the CH24hrs a day. Where does the power shower take the supply from first?

 

[DP]

If your cylinder hold 120l of water and shower is delivery 10l per minute, hot water will have been used up in 12 minutes.

No chance of four people being able to shower.

Know a family with two sons and 300l HW cylinder. Boys take a shower and 300l cylinder is cold. Old man sits down and has a cuppa and then gets his shower. Coil in the cylinder is rated at appro 24kwatts.

If your cylinder is old un with insulation jacket and is gravity HW cylinder replacing the cylinder will help. Some cylinders will reaheat within 30 minutes, some even faster (subject to boiler have the guts to do the hard work)

 

[Tipper]

If you're in a hard water area then the tank, if it's been there a few years could be half full of scale which reduces the effective volume of water held in the tank and so reduces time of avaliable hot water.

When I changed my last HW cylinder I couldn't lift it when drained due to the amount of scale in the bottom of it! Water softener installed shortly after...

 

[laujen]

Thanks apologies for being stupid but I'm still confused. As per my previous question do I need both the immersion and the HW on ?

The cylinder appears to have a sort of polystyrene type jacket on it that you can into if you push hard enough. So a larger cylinder may be the answer?

 

[craig51]

No, you only use the immersio when the HW from the boiler stops working! It will cost a fortune to run for constantly.

Before anyone here can give you any advice, go to your hot water tank (with an immersion heater attached, have a look for a data badge and tell us what it says, in particular the size of the tank. Failing that, tell us how tall it is, and how wide.

 

[laujen]

Thanks guys will try and have a look tonight