Hot water off but water still hot.

Louscorp

theoretica said:

The immersion heater is the thing on the top going to the electric switch on the wall - now off. Only use as a very occasional boost addition.

The temperature dial is for the gas boiler water heating, I would probably want it a bit higher because of legionella.  As mentioned, the red box will be the pump for the boiler.

Can I also ask, should I set the dial back to 80 and the pump back to three bars? These are the only things I've altered.

Bendy_House

Louscorp said:

Have added one pic, does this give enough info?

Oh, yes... It tells us a lot :-) (I'm not sniggering - honestly...)

Ok, I've composed myself.

A - is your immersion heater. This is powered by leccy, and is only used to heat the hot cylinder if your gas boiler is kaput. You can also use it to speed up the heating of your hot cylinder if, say, the water is stone cold and you want to 'help' the gas boiler to reheat it - eg if you've been away and have come back to a cold house and water. Otherwise leave it (item B ) off.

B - is the on/off switch for the immersion heater. This looks currently to be 'off' - unless it's upside-down. Did you turn it off, or was it always off?

C - this is the cylinder thermostat and is what controls the temp of the hot water as heated by your gas boiler. NOT your immersion. This should be at ~60oC which will ensure your water is hot enough, and also 'safe' from Legionnaires. Please put this back to 60oC (or hotter if you want).

D - is your circulating pump. This is what has the three bars? This is connected to your gas boiler, and only works with this. What is it set to at the moment?

Louscorp

Bendy_House said:

Louscorp said:

Have added one pic, does this give enough info?

Oh, yes... It tells us a lot :-) (I'm not sniggering - honestly...)

Ok, I've composed myself.

A - is your immersion heater. This is powered by leccy, and is only used to heat the hot cylinder if your gas boiler is kaput. You can also use it to speed up the heating of your hot cylinder if, say, the water is stone cold and you want to 'help' the gas boiler to reheat it - eg if you've been away and have come back to a cold house and water. Otherwise leave it (item B ) off.

B - is the on/off switch for the immersion heater. This looks currently to be 'off' - unless it's upside-down. Did you turn it off, or was it always off?

C - this is the cylinder thermostat and is what controls the temp of the hot water as heated by your gas boiler. NOT your immersion. This should be at ~60oC which will ensure your water is hot enough, and also 'safe' from Legionnaires. Please put this back to 60oC (or hotter if you want).

D - is your circulating pump. This is what has the three bars? This is connected to your gas boiler, and only works with this. What is it set to at the moment?

This is brilliant, thanks again. So, the switch (B) was already set to off, I have not touched this. Ok, I will set the dial (C) back to at least 60 as instructed. Yes, the circulating pump (D) was set to three bars and I switched it to one bar, I take it I should switch it back to three?
Sooo, if the immersion (A) is off and the hot water is set to off on the boiler downstairs, I can't work out why I have hot water, what is heating it? 

theoretica

How long ago did you turn the hot water to 'off'?  It couldn't just be that the tank insulation means it hasn't cooled down yet?

Louscorp

theoretica said:

How long ago did you turn the hot water to 'off'?  It couldn't just be that the tank insulation means it hasn't cooled down yet?

Probably at least a month ago!

Bendy_House

Louscorp said:

This is brilliant, thanks again. So, the switch (B) was already set to off, I have not touched this. Ok, I will set the dial (C) back to at least 60 as instructed. Yes, the circulating pump (D) was set to three bars and I switched it to one bar, I take it I should switch it back to three?
Sooo, if the immersion (A) is off and the hot water is set to off on the boiler downstairs, I can't work out why I have hot water, what is heating it? 

That's a very good question.

Two possibilities. The first is that the immersion heater switch (B) is fitted upside-down, so on is off and off is on. It doesn't have an indicator light, so it's tricky to tell. On balance, this would be unlikely - almost certainly your electric immersion heater is 'off', as it should be.

The other most likely possibility is that the motorised valves are faulty (these are the silver things above the red pump, and below/in front of it). So, when the CH is on - heating your radiators - some of the boiler's hot water is also getting through to heat up the hot cylinder when it shouldn't be.

[Deleted User]

Hi,

you could test heater switch (B) by switching it 'ON', you should hear it starting to boil, like a kettle, depending on water temp, remember to switch 'OFF'

FreeBear

frugalmacdugal said: you could test heater switch (B) by switching it 'ON', you should hear it starting to boil, like a kettle, depending on water temp, remember to switch 'OFF'

And watch the dial (flashing light if a smart meter) spin like crazy.

Louscorp

[Deleted User] said:

Hi,

you could test heater switch (B) by switching it 'ON', you should hear it starting to boil, like a kettle, depending on water temp, remember to switch 'OFF'

Yep if I switch it on it sounds like a kettle starting to boil. (have turned it off again)

Louscorp

Bendy_House said:

Louscorp said:

This is brilliant, thanks again. So, the switch (B) was already set to off, I have not touched this. Ok, I will set the dial (C) back to at least 60 as instructed. Yes, the circulating pump (D) was set to three bars and I switched it to one bar, I take it I should switch it back to three?
Sooo, if the immersion (A) is off and the hot water is set to off on the boiler downstairs, I can't work out why I have hot water, what is heating it? 

That's a very good question.

Two possibilities. The first is that the immersion heater switch (B) is fitted upside-down, so on is off and off is on. It doesn't have an indicator light, so it's tricky to tell. On balance, this would be unlikely - almost certainly your electric immersion heater is 'off', as it should be.

The other most likely possibility is that the motorised valves are faulty (these are the silver things above the red pump, and below/in front of it). So, when the CH is on - heating your radiators - some of the boiler's hot water is also getting through to heat up the hot cylinder when it shouldn't be.

I switched it (B) on and it sounded like a kettle starting to boil, I switched it back off afterwards. It seem that whether the heating is on or off the hot water is consistently hot. I'm flummoxed.