A few DHW questions

[mrbg07546]

i got a modern system boiler and a unistor 250.

I had a few questions.

1.what is the typical temperature loss of. DHW. So for example if temperature comes in at 55 degrees. How much would you typically lose in say 6 hour So?

2. Ok presuming you had 250 go in when hot water was running. And you didn’t have hot water running once full. If you used 125L would that mean( as you don’t have hot water running), it would be refilled with cold water so you would reduce the tempreture drastically as you have 125L of cold water mixed in?

 

[AGAS]

1.what is the typical temperature loss of. DHW. So for example if temperature comes in at 55 degrees. How much would you typically lose in say 6 hour So?

2. Ok presuming you had 250 go in when hot water was running. And you didn’t have hot water running once full. If you used 125L would that mean( as you don’t have hot water running), it would be refilled with cold water so you would reduce the tempreture drastically as you have 125L of cold water mixed in?

why are you worried when the water would probably be heated up to stat temp within 10mins

 

[mrbg07546]

why are you worried when the water would probably be heated up to stat temp within 10mins

Because I have it on timer. 30 minutes in morning and 30 minutes in afternoon

 

[AGAS]

Because I have it on timer. 30 minutes in morning and 30 minutes in afternoon

whats up ? you've spent all your money on your vaillant gear

 

[Elkato531]

The water in the cylinder should be stratified. ie hot water rises to the top and the incoming cold sits at the bottom. The hot water is drawn off from the top of the cylinder. There will be a bit of mixing as new cold is introduced but you should still have the hottest water at the top

 

[dilalio]

You don't have to time it to go off when cylinder is up to temp... the stat will do that!

 

[mrbg07546]

You don't have to time it to go off when cylinder is up to temp... the stat will do that!

To save money? Why do you want it to keep heating something when you don’t need it to

 

[Dan Robinson]

You're not Heating something. You're maintaining something. A cylinder will cost you less than 20 a day to keep hot.

There's these amazing new devices. They're called...... Wait for it........



Thermostats.




Your installer should have gone through it with you. but obviously he was a moron.

 

[mrbg07546]

You're not Heating something. You're maintaining something. A cylinder will cost you less than 20 a day to keep hot.

There's these amazing new devices. They're called...... Wait for it........



Thermostats.




Your installer should have gone through it with you. but obviously he was a moron.

I’ve read a few threads. Having it on all the time vs having small intervals to heat cylinder. The rule is that using a timer to heat it , is more cost effcient. And given our current regime means we never run out of water given our usage, I can’t see why it is at a better option

 

[oldbuffer]

If you look up the Vaillant literature you'll see the heat loss is 1.44Kw in 24hours. It won't be linear, but take the first 6 hours as losing half the heat you'll lose 0.72Kw, but its probably less.

 

[Dan Robinson]

I’ve read a few threads

And this forum is full of threads with misinformation and DIY numpties giving stupid advice.

The rule is that using a timer to heat it , is more cost effcient

What rule?

, I can’t see why it is at a better option

Then why ask the question?